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* mm/ioremap: add slab availability checking in ioremap_protBaoquan He2023-08-181-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Several architectures has done checking if slab if available in ioremap_prot(). In fact it should be done in generic ioremap_prot() since on any architecutre, slab allocator must be available before get_vm_area_caller() and vunmap() are used. Add the checking into generic_ioremap_prot(). Link: https://lkml.kernel.org/r/20230706154520.11257-7-bhe@redhat.com Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Chris Zankel <chris@zankel.net> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonas Bonn <jonas@southpole.se> Cc: Matthew Wilcox <willy@infradead.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Rich Felker <dalias@libc.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: ioremap: allow ARCH to have its own ioremap method definitionBaoquan He2023-08-181-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Architectures can be converted to GENERIC_IOREMAP, to take standard ioremap_xxx() and iounmap() way. But some ARCH-es could have specific handling for ioremap_prot(), ioremap() and iounmap(), than standard methods. In oder to convert these ARCH-es to take GENERIC_IOREMAP method, allow these architecutres to have their own ioremap_prot(), ioremap() and iounmap() definitions. Link: https://lkml.kernel.org/r/20230706154520.11257-6-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Brian Cain <bcain@quicinc.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Chris Zankel <chris@zankel.net> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonas Bonn <jonas@southpole.se> Cc: Matthew Wilcox <willy@infradead.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Rich Felker <dalias@libc.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/ioremap: define generic_ioremap_prot() and generic_iounmap()Christophe Leroy2023-08-181-6/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Define a generic version of ioremap_prot() and iounmap() that architectures can call after they have performed the necessary alteration to parameters and/or necessary verifications. Link: https://lkml.kernel.org/r/20230706154520.11257-5-bhe@redhat.com Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Chris Zankel <chris@zankel.net> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonas Bonn <jonas@southpole.se> Cc: Matthew Wilcox <willy@infradead.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Rich Felker <dalias@libc.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_ext: move functions around for minor cleanups to page_extKemeng Shi2023-08-181-50/+46
| | | | | | | | | | | | | 1. move page_ext_get and page_ext_put down to remove forward declaration of lookup_page_ext. 2. move page_ext_init_flatmem_late down to existing non SPARS block to remove a new non SPARS block and to keep code for non SPARS tight. Link: https://lkml.kernel.org/r/20230714114749.1743032-4-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_ext: remove rollback for untouched mem_section in online_page_extKemeng Shi2023-08-181-0/+1
| | | | | | | | | | | | | | | If init_section_page_ext failed, we only need rollback for mem_section before failed mem_section. Make rollback end point to failed mem_section to remove unnecessary rollback. As pfn += PAGES_PER_SECTION will be executed even if init_section_page_ext failed. So pfn points to mem_section after failed mem_section. Subtract one mem_section from pfn to get failed mem_section. Link: https://lkml.kernel.org/r/20230714114749.1743032-3-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_ext: remove unused return value of offline_page_extKemeng Shi2023-08-181-3/+1
| | | | | | | | | | | | | | | | | | | Patch series "minor cleanups for page_ext". This series contains some random minor cleanups for page_ext. More details can be found in respective patches. This patch (of 3): offline_page_ext always returns 0 and no caller checks the return value. Just remove unused return value of offline_page_ext. Link: https://lkml.kernel.org/r/20230714114749.1743032-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20230714114749.1743032-2-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* migrate: use folio_set_bh() instead of set_bh_page()Matthew Wilcox (Oracle)2023-08-181-1/+1
| | | | | | | | | | | | | | | | | | | This function was converted before folio_set_bh() existed. Catch up to the new API. Link: https://lkml.kernel.org/r/20230713035512.4139457-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Pankaj Raghav <p.raghav@samsung.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Tom Rix <trix@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_table_check: remove unused parameter in [__]page_table_check_pud_setKemeng Shi2023-08-181-2/+1
| | | | | | | | | | Remove unused addr in __page_table_check_pud_set and page_table_check_pud_set. Link: https://lkml.kernel.org/r/20230713172636.1705415-9-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_table_check: remove unused parameter in [__]page_table_check_pmd_setKemeng Shi2023-08-181-2/+1
| | | | | | | | | | Remove unused addr in __page_table_check_pmd_set and page_table_check_pmd_set. Link: https://lkml.kernel.org/r/20230713172636.1705415-8-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_table_check: remove unused parameter in [__]page_table_check_pte_setKemeng Shi2023-08-181-2/+1
| | | | | | | | | | Remove unused addr in __page_table_check_pte_set and page_table_check_pte_set. Link: https://lkml.kernel.org/r/20230713172636.1705415-7-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_table_check: remove unused parameter in [__]page_table_check_pud_clearKemeng Shi2023-08-181-3/+2
| | | | | | | | | | Remove unused addr in __page_table_check_pud_clear and page_table_check_pud_clear. Link: https://lkml.kernel.org/r/20230713172636.1705415-6-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_table_check: remove unused parameter in [__]page_table_check_pmd_clearKemeng Shi2023-08-181-3/+2
| | | | | | | | | | Remove unused addr in page_table_check_pmd_clear and __page_table_check_pmd_clear. Link: https://lkml.kernel.org/r/20230713172636.1705415-5-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_table_check: remove unused parameter in [__]page_table_check_pte_clearKemeng Shi2023-08-181-4/+3
| | | | | | | | | | Remove unused addr in page_table_check_pte_clear and __page_table_check_pte_clear. Link: https://lkml.kernel.org/r/20230713172636.1705415-4-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_table_check: remove unused parameters in page_table_check_set()Kemeng Shi2023-08-181-8/+4
| | | | | | | | | Remove unused mm and addr in page_table_check_set(). Link: https://lkml.kernel.org/r/20230713172636.1705415-3-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/page_table_check: remove unused parameters in page_table_check_clear()Kemeng Shi2023-08-181-8/+4
| | | | | | | | | | | | | | | | | | | | | | Patch series "Remove unused parameters in page_table_check". This series remove unused parameters in functions from page_table_check. The first 2 patches remove unused mm and addr parameters in static common functions page_table_check_clear and page_table_check_set. The last 6 patches remove unused addr parameter in some externed functions which only need addr for cleaned page_table_check_clear or page_table_check_set. There is no intended functional change. This patch (of 8): Remove unused mm and addr in function page_table_check_clear(). Link: https://lkml.kernel.org/r/20230713172636.1705415-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20230713172636.1705415-2-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/memcg: fix obsolete comment above MEM_CGROUP_MAX_RECLAIM_LOOPSMiaohe Lin2023-08-181-1/+1
| | | | | | | | | | | | | | | | | Since commit 5660048ccac8 ("mm: move memcg hierarchy reclaim to generic reclaim code"), mem_cgroup_hierarchical_reclaim() is already renamed to mem_cgroup_soft_reclaim(). Update the corresponding comment. Link: https://lkml.kernel.org/r/20230713121432.273381-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/huge_memory: use RMAP_NONE when calling page_add_anon_rmap()Miaohe Lin2023-08-181-1/+1
| | | | | | | | | | | | It's more convenient and readable to use RMAP_NONE instead of false when calling page_add_anon_rmap(). No functional change intended. Link: https://lkml.kernel.org/r/20230713120557.218592-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/hwpoison: check if a raw page in a hugetlb folio is raw HWPOISONJiaqi Yan2023-08-181-2/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the functionality, is_raw_hwpoison_page_in_hugepage, to tell if a raw page in a hugetlb folio is HWPOISON. This functionality relies on RawHwpUnreliable to be not set; otherwise hugepage's raw HWPOISON list becomes meaningless. is_raw_hwpoison_page_in_hugepage holds mf_mutex in order to synchronize with folio_set_hugetlb_hwpoison and folio_free_raw_hwp who iterate, insert, or delete entry in raw_hwp_list. llist itself doesn't ensure insertion and removal are synchornized with the llist_for_each_entry used by is_raw_hwpoison_page_in_hugepage (unless iterated entries are already deleted from the list). Caller can minimize the overhead of lock cycles by first checking HWPOISON flag of the folio. Exports this functionality to be immediately used in the read operation for hugetlbfs. Link: https://lkml.kernel.org/r/20230713001833.3778937-3-jiaqiyan@google.com Signed-off-by: Jiaqi Yan <jiaqiyan@google.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: James Houghton <jthoughton@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/hwpoison: delete all entries before traversal in __folio_free_raw_hwpJiaqi Yan2023-08-181-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Improve hugetlbfs read on HWPOISON hugepages", v4. Today when hardware memory is corrupted in a hugetlb hugepage, kernel leaves the hugepage in pagecache [1]; otherwise future mmap or read will suject to silent data corruption. This is implemented by returning -EIO from hugetlb_read_iter immediately if the hugepage has HWPOISON flag set. Since memory_failure already tracks the raw HWPOISON subpages in a hugepage, a natural improvement is possible: if userspace only asks for healthy subpages in the pagecache, kernel can return these data. This patchset implements this improvement. It consist of three parts. The 1st commit exports the functionality to tell if a subpage inside a hugetlb hugepage is a raw HWPOISON page. The 2nd commit teaches hugetlbfs_read_iter to return as many healthy bytes as possible. The 3rd commit properly tests this new feature. [1] commit 8625147cafaa ("hugetlbfs: don't delete error page from pagecache") This patch (of 4): Traversal on llist (e.g. llist_for_each_safe) is only safe AFTER entries are deleted from the llist. Correct the way __folio_free_raw_hwp deletes and frees raw_hwp_page entries in raw_hwp_list: first llist_del_all, then kfree within llist_for_each_safe. As of today, concurrent adding, deleting, and traversal on raw_hwp_list from hugetlb.c and/or memory-failure.c are fine with each other. Note this is guaranteed partly by the lock-free nature of llist, and partly by holding hugetlb_lock and/or mf_mutex. For example, as llist_del_all is lock-free with itself, folio_clear_hugetlb_hwpoison()s from __update_and_free_hugetlb_folio and memory_failure won't need explicit locking when freeing the raw_hwp_list. New code that manipulates raw_hwp_list must be careful to ensure the concurrency correctness. Link: https://lkml.kernel.org/r/20230713001833.3778937-1-jiaqiyan@google.com Link: https://lkml.kernel.org/r/20230713001833.3778937-2-jiaqiyan@google.com Signed-off-by: Jiaqi Yan <jiaqiyan@google.com> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: James Houghton <jthoughton@google.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/mmap: move vma operations to mm_struct out of the critical section of ↵Yu Ma2023-08-181-8/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | file mapping lock UnixBench/Execl represents a class of workload where bash scripts are spawned frequently to do some short jobs. When running multiple parallel tasks, hot osq_lock is observed from do_mmap and exit_mmap. Both of them come from load_elf_binary through the call chain "execl->do_execveat_common->bprm_execve->load_elf_binary". In do_mmap,it will call mmap_region to create vma node, initialize it and insert it to vma maintain structure in mm_struct and i_mmap tree of the mapping file, then increase map_count to record the number of vma nodes used. The hot osq_lock is to protect operations on file's i_mmap tree. For the mm_struct member change like vma insertion and map_count update, they do not affect i_mmap tree. Move those operations out of the lock's critical section, to reduce hold time on the lock. With this change, on Intel Sapphire Rapids 112C/224T platform, based on v6.0-rc6, the 160 parallel score improves by 12%. The patch has no obvious performance gain on v6.5-rc1 due to regression of this benchmark from this commit f1a7941243c102a44e8847e3b94ff4ff3ec56f25 (mm: convert mm's rss stats into percpu_counter). Related discussion and conclusion can be referred at the mail thread initiated by 0day as below: Link: https://lore.kernel.org/linux-mm/a4aa2e13-7187-600b-c628-7e8fb108def0@intel.com/ Link: https://lkml.kernel.org/r/20230712145739.604215-1-yu.ma@intel.com Signed-off-by: Yu Ma <yu.ma@intel.com> Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A . Shutemov <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Zhu, Lipeng <lipeng.zhu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/pgtable: notes on pte_offset_map[_lock]()Hugh Dickins2023-08-181-0/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a block of comments on pte_offset_map_lock(), pte_offset_map() and pte_offset_map_nolock() to mm/pgtable-generic.c, to help explain them. Link: https://lkml.kernel.org/r/b791c3b0-25c6-a263-d785-d564344eb644@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Russell King <linux@armlinux.org.uk> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/khugepaged: delete khugepaged_collapse_pte_mapped_thps()Hugh Dickins2023-08-181-110/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that retract_page_tables() can retract page tables reliably, without depending on trylocks, delete all the apparatus for khugepaged to try again later: khugepaged_collapse_pte_mapped_thps() etc; and free up the per-mm memory which was set aside for that in the khugepaged_mm_slot. But one part of that is worth keeping: when hpage_collapse_scan_file() found SCAN_PTE_MAPPED_HUGEPAGE, that address was noted in the mm_slot to be tried for retraction later - catching, for example, page tables where a reversible mprotect() of a portion had required splitting the pmd, but now it can be recollapsed. Call collapse_pte_mapped_thp() directly in this case (why was it deferred before? I assume an issue with needing mmap_lock for write, but now it's only needed for read). [hughd@google.com: fix mmap_locked handlng] Link: https://lkml.kernel.org/r/bfc6cab2-497f-32bf-dd5-98dc1987e4a9@google.com Link: https://lkml.kernel.org/r/a5dce57-6dfa-5559-4698-e817eb2f993@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Russell King <linux@armlinux.org.uk> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/khugepaged: collapse_pte_mapped_thp() with mmap_read_lock()Hugh Dickins2023-08-181-94/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bring collapse_and_free_pmd() back into collapse_pte_mapped_thp(). It does need mmap_read_lock(), but it does not need mmap_write_lock(), nor vma_start_write() nor i_mmap lock nor anon_vma lock. All racing paths are relying on pte_offset_map_lock() and pmd_lock(), so use those. Follow the pattern in retract_page_tables(); and using pte_free_defer() removes most of the need for tlb_remove_table_sync_one() here; but call pmdp_get_lockless_sync() to use it in the PAE case. First check the VMA, in case page tables are being torn down: from JannH. Confirm the preliminary find_pmd_or_thp_or_none() once page lock has been acquired and the page looks suitable: from then on its state is stable. However, collapse_pte_mapped_thp() was doing something others don't: freeing a page table still containing "valid" entries. i_mmap lock did stop a racing truncate from double-freeing those pages, but we prefer collapse_pte_mapped_thp() to clear the entries as usual. Their TLB flush can wait until the pmdp_collapse_flush() which follows, but the mmu_notifier_invalidate_range_start() has to be done earlier. Do the "step 1" checking loop without mmu_notifier: it wouldn't be good for khugepaged to keep on repeatedly invalidating a range which is then found unsuitable e.g. contains COWs. "step 2", which does the clearing, must then be more careful (after dropping ptl to do mmu_notifier), with abort prepared to correct the accounting like "step 3". But with those entries now cleared, "step 4" (after dropping ptl to do pmd_lock) is kept safe by the huge page lock, which stops new PTEs from being faulted in. [hughd@google.com: don't set mmap_locked = true in madvise_collapse()] Link: https://lkml.kernel.org/r/d3d9ff14-ef8-8f84-e160-bfa1f5794275@google.com [hughd@google.com: use ptep_clear() instead of pte_clear()] Link: https://lkml.kernel.org/r/e0197433-8a47-6a65-534d-eda26eeb78b0@google.com Link: https://lkml.kernel.org/r/b53be6a4-7715-51f9-aad-f1347dcb7c4@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Russell King <linux@armlinux.org.uk> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/khugepaged: retract_page_tables() without mmap or vma lockHugh Dickins2023-08-181-103/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simplify shmem and file THP collapse's retract_page_tables(), and relax its locking: to improve its success rate and to lessen impact on others. Instead of its MADV_COLLAPSE case doing set_huge_pmd() at target_addr of target_mm, leave that part of the work to madvise_collapse() calling collapse_pte_mapped_thp() afterwards: just adjust collapse_file()'s result code to arrange for that. That spares retract_page_tables() four arguments; and since it will be successful in retracting all of the page tables expected of it, no need to track and return a result code itself. It needs i_mmap_lock_read(mapping) for traversing the vma interval tree, but it does not need i_mmap_lock_write() for that: page_vma_mapped_walk() allows for pte_offset_map_lock() etc to fail, and uses pmd_lock() for THPs. retract_page_tables() just needs to use those same spinlocks to exclude it briefly, while transitioning pmd from page table to none: so restore its use of pmd_lock() inside of which pte lock is nested. Users of pte_offset_map_lock() etc all now allow for them to fail: so retract_page_tables() now has no use for mmap_write_trylock() or vma_try_start_write(). In common with rmap and page_vma_mapped_walk(), it does not even need the mmap_read_lock(). But those users do expect the page table to remain a good page table, until they unlock and rcu_read_unlock(): so the page table cannot be freed immediately, but rather by the recently added pte_free_defer(). Use the (usually a no-op) pmdp_get_lockless_sync() to send an interrupt when PAE, and pmdp_collapse_flush() did not already do so: to make sure that the start,pmdp_get_lockless(),end sequence in __pte_offset_map() cannot pick up a pmd entry with mismatched pmd_low and pmd_high. retract_page_tables() can be enhanced to replace_page_tables(), which inserts the final huge pmd without mmap lock: going through an invalid state instead of pmd_none() followed by fault. But that enhancement does raise some more questions: leave it until a later release. Link: https://lkml.kernel.org/r/f88970d9-d347-9762-ae6d-da978e8a4df@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Russell King <linux@armlinux.org.uk> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/pgtable: add pte_free_defer() for pgtable as pageHugh Dickins2023-08-181-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the generic pte_free_defer(), to call pte_free() via call_rcu(). pte_free_defer() will be called inside khugepaged's retract_page_tables() loop, where allocating extra memory cannot be relied upon. This version suits all those architectures which use an unfragmented page for one page table (none of whose pte_free()s use the mm arg which was passed to it). Link: https://lkml.kernel.org/r/78e921b0-b681-a1b0-dc20-44c9efa4ef3c@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Russell King <linux@armlinux.org.uk> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/pgtable: add PAE safety to __pte_offset_map()Hugh Dickins2023-08-181-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a faint risk that __pte_offset_map(), on a 32-bit architecture with a 64-bit pmd_t e.g. x86-32 with CONFIG_X86_PAE=y, would succeed on a pmdval assembled from a pmd_low and a pmd_high which never belonged together: their combination not pointing to a page table at all, perhaps not even a valid pfn. pmdp_get_lockless() is not enough to prevent that. Guard against that (on such configs) by local_irq_save() blocking TLB flush between present updates, as linux/pgtable.h suggests. It's only needed around the pmdp_get_lockless() in __pte_offset_map(): a race when __pte_offset_map_lock() repeats the pmdp_get_lockless() after getting the lock, would just send it back to __pte_offset_map() again. Complement this pmdp_get_lockless_start() and pmdp_get_lockless_end(), used only locally in __pte_offset_map(), with a pmdp_get_lockless_sync() synonym for tlb_remove_table_sync_one(): to send the necessary interrupt at the right moment on those configs which do not already send it. CONFIG_GUP_GET_PXX_LOW_HIGH is enabled when required by mips, sh and x86. It is not enabled by arm-32 CONFIG_ARM_LPAE: my understanding is that Will Deacon's 2020 enhancements to READ_ONCE() are sufficient for arm. It is not enabled by arc, but its pmd_t is 32-bit even when pte_t 64-bit. Limit the IRQ disablement to CONFIG_HIGHPTE? Perhaps, but would need a little more work, to retry if pmd_low good for page table, but pmd_high non-zero from THP (and that might be making x86-specific assumptions). Link: https://lkml.kernel.org/r/3adcd8f-9191-2df1-d7ea-c4877698aad@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Russell King <linux@armlinux.org.uk> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/pgtable: add rcu_read_lock() and rcu_read_unlock()sHugh Dickins2023-08-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm: free retracted page table by RCU", v3. Some mmap_lock avoidance i.e. latency reduction. Initially just for the case of collapsing shmem or file pages to THPs: the usefulness of MADV_COLLAPSE on shmem is being limited by that mmap_write_lock it currently requires. Likely to be relied upon later in other contexts e.g. freeing of empty page tables (but that's not work I'm doing). mmap_write_lock avoidance when collapsing to anon THPs? Perhaps, but again that's not work I've done: a quick attempt was not as easy as the shmem/file case. These changes (though of course not these exact patches) have been in Google's data centre kernel for three years now: we do rely upon them. This patch (of 13): Before putting them to use (several commits later), add rcu_read_lock() to pte_offset_map(), and rcu_read_unlock() to pte_unmap(). Make this a separate commit, since it risks exposing imbalances: prior commits have fixed all the known imbalances, but we may find some have been missed. Link: https://lkml.kernel.org/r/7cd843a9-aa80-14f-5eb2-33427363c20@google.com Link: https://lkml.kernel.org/r/d3b01da5-2a6-833c-6681-67a3e024a16f@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Russell King <linux@armlinux.org.uk> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/memory: pass folio into do_page_mkwrite()Sidhartha Kumar2023-08-181-4/+3
| | | | | | | | | | | | | | Saves one implicit call to compound_head(). I'm not sure if I should change the name of the function to do_folio_mkwrite() and update the description comment to reference a folio as the vm_op is still called page_mkwrite. Link: https://lkml.kernel.org/r/20230711053544.156617-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: memory-failure: fix race window when trying to get hugetlb folioMiaohe Lin2023-08-181-4/+16
| | | | | | | | | | | | | | page_folio() is fetched before calling get_hwpoison_hugetlb_folio() without hugetlb_lock being held. So hugetlb page could be demoted before get_hwpoison_hugetlb_folio() holding hugetlb_lock but after page_folio() is fetched. So get_hwpoison_hugetlb_folio() will hold unexpected extra refcnt of hugetlb folio while leaving demoted page un-refcnted. Link: https://lkml.kernel.org/r/20230711055016.2286677-9-linmiaohe@huawei.com Fixes: 25182f05ffed ("mm,hwpoison: fix race with hugetlb page allocation") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: memory-failure: fetch compound head after extra page refcnt is heldMiaohe Lin2023-08-181-2/+1
| | | | | | | | | | | | Page might become thp, huge page or being splited after compound head is fetched but before page refcnt is bumped. So hpage might be a tail page leading to VM_BUG_ON_PAGE(PageTail(page)) in PageTransHuge(). Link: https://lkml.kernel.org/r/20230711055016.2286677-8-linmiaohe@huawei.com Fixes: 415c64c1453a ("mm/memory-failure: split thp earlier in memory error handling") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: memory-failure: minor cleanup for comments and codestyleMiaohe Lin2023-08-181-6/+6
| | | | | | | | | | Fix some wrong function names and grammar error in comments. Also remove unneeded space after for_each_process. No functional change intended. Link: https://lkml.kernel.org/r/20230711055016.2286677-7-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: memory-failure: remove unneeded header filesMiaohe Lin2023-08-181-3/+0
| | | | | | | | | Remove some unneeded header files. No functional change intended. Link: https://lkml.kernel.org/r/20230711055016.2286677-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: memory-failure: use local variable huge to check hugetlb pageMiaohe Lin2023-08-181-2/+2
| | | | | | | | | | | Use local variable huge to check whether page is hugetlb page to avoid calling PageHuge() multiple times to save cpu cycles. PageHuge() will be stable while extra page refcnt is held. Link: https://lkml.kernel.org/r/20230711055016.2286677-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: memory-failure: don't account hwpoison_filter() filtered pagesMiaohe Lin2023-08-181-1/+2
| | | | | | | | | | | | mf_generic_kill_procs() will return -EOPNOTSUPP when hwpoison_filter() filtered dax page. In that case, action_result() isn't expected to be called to update mf_stats. This will results in inaccurate but benign memory failure handling statistics. Link: https://lkml.kernel.org/r/20230711055016.2286677-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: memory-failure: ensure moving HWPoison flag to the raw error pagesMiaohe Lin2023-08-181-0/+2
| | | | | | | | | | | | | | | | If hugetlb_vmemmap_optimized is enabled, folio_clear_hugetlb_hwpoison() called from try_memory_failure_hugetlb() won't transfer HWPoison flag to subpages while folio's HWPoison flag is cleared. So when trying to free this hugetlb page into buddy, folio_clear_hugetlb_hwpoison() is not called to move HWPoison flag from head page to the raw error pages even if now hugetlb_vmemmap_optimized is cleared. This will results in HWPoisoned page being used again and raw_hwp_page leak. Link: https://lkml.kernel.org/r/20230711055016.2286677-3-linmiaohe@huawei.com Fixes: ac5fcde0a96a ("mm, hwpoison: make unpoison aware of raw error info in hwpoisoned hugepage") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: memory-failure: remove unneeded PageHuge() checkMiaohe Lin2023-08-181-3/+0
| | | | | | | | | | | | | | | | | | | | | Patch series "A few fixup and cleanup patches for memory-failure", v2. This series contains a few fixup patches to fix inaccurate mf_stats, fix race window when trying to get hugetlb folio and so on. Also there is minor cleanup for comments and codestyle. More details can be found in the respective changelogs. This patch (of 8): PageHuge() check in me_huge_page() is just for potential problems. Remove it as it's actually dead code and won't catch anything. Link: https://lkml.kernel.org/r/20230711055016.2286677-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20230711055016.2286677-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/memory_hotplug: document the signal_pending() check in offline_pages()David Hildenbrand2023-08-181-0/+5
| | | | | | | | | | | | | | | | | | | | | | Let's update the documentation that any signal is sufficient, and add a comment that not only checking for fatal signals is historical baggage: changing it now could break existing user space. although unlikely. For example, when an app provides a custom SIGALRM handler and triggers memory offlining, the timeout cmd would no longer stop memory offlining, because SIGALRM would no longer be considered a fatal signal. Note that using signal_pending() instead of fatal_signal_pending() is an anti-pattern, but slowly deprecating that behavior to eventually change it in the far future is probably not worth the effort. If this ever becomes relevant for user-space, we might want to rethink. Link: https://lkml.kernel.org/r/20230711174050.603820-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/mm_init.c: mark check_for_memory() as __initHaifeng Xu2023-08-181-1/+1
| | | | | | | | | | | | The only caller of check_for_memory() is free_area_init(), which is annotated with __init, so it should be safe to also mark the former as __init. Link: https://lkml.kernel.org/r/20230710093750.1294-1-haifeng.xu@shopee.com Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* zsmalloc: remove obj_tagged()Sergey Senozhatsky2023-08-181-22/+7
| | | | | | | | | | | | | | obj_tagged() is not needed at this point, because objects can only have one tag: OBJ_ALLOCATED_TAG. We needed obj_tagged() for the zsmalloc LRU implementation, which has now been removed. Simplify zsmalloc code and revert to the previous implementation that was in place before the zsmalloc LRU series. Link: https://lkml.kernel.org/r/20230709025817.3842416-1-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Nhat Pham <nphamcs@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: userfaultfd: support UFFDIO_POISON for hugetlbfsAxel Rasmussen2023-08-182-2/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The behavior here is the same as it is for anon/shmem. This is done separately because hugetlb pte marker handling is a bit different. Link: https://lkml.kernel.org/r/20230707215540.2324998-6-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Acked-by: Peter Xu <peterx@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Gaosheng Cui <cuigaosheng1@huawei.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: userfaultfd: add new UFFDIO_POISON ioctl: fixHugh Dickins2023-08-181-0/+4
| | | | | | | | | | | | Smatch has observed that pte_offset_map_lock() is now allowed to fail, and then ptl should not be unlocked. Use -EAGAIN here like elsewhere. Link: https://lkml.kernel.org/r/bc7bba61-d34f-ad3a-ccf1-c191585ef851@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Axel Rasmussen <axelrasmussen@google.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: userfaultfd: add new UFFDIO_POISON ioctlAxel Rasmussen2023-08-181-1/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The basic idea here is to "simulate" memory poisoning for VMs. A VM running on some host might encounter a memory error, after which some page(s) are poisoned (i.e., future accesses SIGBUS). They expect that once poisoned, pages can never become "un-poisoned". So, when we live migrate the VM, we need to preserve the poisoned status of these pages. When live migrating, we try to get the guest running on its new host as quickly as possible. So, we start it running before all memory has been copied, and before we're certain which pages should be poisoned or not. So the basic way to use this new feature is: - On the new host, the guest's memory is registered with userfaultfd, in either MISSING or MINOR mode (doesn't really matter for this purpose). - On any first access, we get a userfaultfd event. At this point we can communicate with the old host to find out if the page was poisoned. - If so, we can respond with a UFFDIO_POISON - this places a swap marker so any future accesses will SIGBUS. Because the pte is now "present", future accesses won't generate more userfaultfd events, they'll just SIGBUS directly. UFFDIO_POISON does not handle unmapping previously-present PTEs. This isn't needed, because during live migration we want to intercept all accesses with userfaultfd (not just writes, so WP mode isn't useful for this). So whether minor or missing mode is being used (or both), the PTE won't be present in any case, so handling that case isn't needed. Similarly, UFFDIO_POISON won't replace existing PTE markers. This might be okay to do, but it seems to be safer to just refuse to overwrite any existing entry (like a UFFD_WP PTE marker). Link: https://lkml.kernel.org/r/20230707215540.2324998-5-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Acked-by: Peter Xu <peterx@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Gaosheng Cui <cuigaosheng1@huawei.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: userfaultfd: extract file size check out into a helperAxel Rasmussen2023-08-181-18/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This code is already duplicated twice, and UFFDIO_POISON will do the same check a third time. So, it's worth extracting into a helper to save repetitive lines of code. Link: https://lkml.kernel.org/r/20230707215540.2324998-4-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Reviewed-by: Peter Xu <peterx@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Gaosheng Cui <cuigaosheng1@huawei.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: make PTE_MARKER_SWAPIN_ERROR more generalAxel Rasmussen2023-08-186-23/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "add UFFDIO_POISON to simulate memory poisoning with UFFD", v4. This series adds a new userfaultfd feature, UFFDIO_POISON. See commit 4 for a detailed description of the feature. This patch (of 8): Future patches will reuse PTE_MARKER_SWAPIN_ERROR to implement UFFDIO_POISON, so make some various preparations for that: First, rename it to just PTE_MARKER_POISONED. The "SWAPIN" can be confusing since we're going to re-use it for something not really related to swap. This can be particularly confusing for things like hugetlbfs, which doesn't support swap whatsoever. Also rename some various helper functions. Next, fix pte marker copying for hugetlbfs. Previously, it would WARN on seeing a PTE_MARKER_SWAPIN_ERROR, since hugetlbfs doesn't support swap. But, since we're going to re-use it, we want it to go ahead and copy it just like non-hugetlbfs memory does today. Since the code to do this is more complicated now, pull it out into a helper which can be re-used in both places. While we're at it, also make it slightly more explicit in its handling of e.g. uffd wp markers. For non-hugetlbfs page faults, instead of returning VM_FAULT_SIGBUS for an error entry, return VM_FAULT_HWPOISON. For most cases this change doesn't matter, e.g. a userspace program would receive a SIGBUS either way. But for UFFDIO_POISON, this change will let KVM guests get an MCE out of the box, instead of giving a SIGBUS to the hypervisor and requiring it to somehow inject an MCE. Finally, for hugetlbfs faults, handle PTE_MARKER_POISONED, and return VM_FAULT_HWPOISON_LARGE in such cases. Note that this can't happen today because the lack of swap support means we'll never end up with such a PTE anyway, but this behavior will be needed once such entries *can* show up via UFFDIO_POISON. Link: https://lkml.kernel.org/r/20230707215540.2324998-1-axelrasmussen@google.com Link: https://lkml.kernel.org/r/20230707215540.2324998-2-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Acked-by: Peter Xu <peterx@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Gaosheng Cui <cuigaosheng1@huawei.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/memcg: minor cleanup for MEM_CGROUP_ID_MAXMiaohe Lin2023-08-181-0/+1
| | | | | | | | | | | | | | | | | | | | | MEM_CGROUP_ID_MAX is only used when CONFIG_MEMCG is configured. So remove unneeded !CONFIG_MEMCG variant. Also it's only used in mem_cgroup_alloc(), so move it from memcontrol.h to memcontrol.c. And further define it as: #define MEM_CGROUP_ID_MAX ((1UL << MEM_CGROUP_ID_SHIFT) - 1) so if someone changes MEM_CGROUP_ID_SHIFT in the future, then MEM_CGROUP_ID_MAX will be updated accordingly, as suggested by Muchun. Link: https://lkml.kernel.org/r/20230708023304.1184111-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/memory: convert do_read_fault() to use foliosSidhartha Kumar2023-08-181-2/+4
| | | | | | | | | | Saves one implicit call to compound_head(). Link: https://lkml.kernel.org/r/20230706163847.403202-4-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/memory: convert do_shared_fault() to foliosSidhartha Kumar2023-08-181-4/+7
| | | | | | | | | | Saves three implicit calls to compound_head(). Link: https://lkml.kernel.org/r/20230706163847.403202-3-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/memory: convert wp_page_shared() to use foliosSidhartha Kumar2023-08-181-11/+11
| | | | | | | | | | Saves six implicit calls to compound_head(). Link: https://lkml.kernel.org/r/20230706163847.403202-2-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/memory: convert do_page_mkwrite() to use foliosSidhartha Kumar2023-08-181-5/+5
| | | | | | | | | | Saves one implicit call to compound_head(). Link: https://lkml.kernel.org/r/20230706163847.403202-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: hugetlb_vmemmap: fix a race between vmemmap pmd splitMuchun Song2023-08-181-20/+14
| | | | | | | | | | | | | | | | | | | | The local variable @page in __split_vmemmap_huge_pmd() to obtain a pmd page without holding page_table_lock may possiblely get the page table page instead of a huge pmd page. The effect may be in set_pte_at() since we may pass an invalid page struct, if set_pte_at() wants to access the page struct (e.g. CONFIG_PAGE_TABLE_CHECK is enabled), it may crash the kernel. So fix it. And inline __split_vmemmap_huge_pmd() since it only has one user. Link: https://lkml.kernel.org/r/20230707033859.16148-1-songmuchun@bytedance.com Fixes: d8d55f5616cf ("mm: sparsemem: use page table lock to protect kernel pmd operations") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 08:52:38 +0000