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* maple_tree: fix mas_empty_area_rev() null pointer dereferenceLiam R. Howlett14 days1-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | Currently the code calls mas_start() followed by mas_data_end() if the maple state is MA_START, but mas_start() may return with the maple state node == NULL. This will lead to a null pointer dereference when checking information in the NULL node, which is done in mas_data_end(). Avoid setting the offset if there is no node by waiting until after the maple state is checked for an empty or single entry state. A user could trigger the events to cause a kernel oops by unmapping all vmas to produce an empty maple tree, then mapping a vma that would cause the scenario described above. Link: https://lkml.kernel.org/r/20240422203349.2418465-1-Liam.Howlett@oracle.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reported-by: Marius Fleischer <fleischermarius@gmail.com> Closes: https://lore.kernel.org/lkml/CAJg=8jyuSxDL6XvqEXY_66M20psRK2J53oBTP+fjV5xpW2-R6w@mail.gmail.com/ Link: https://lore.kernel.org/lkml/CAJg=8jyuSxDL6XvqEXY_66M20psRK2J53oBTP+fjV5xpW2-R6w@mail.gmail.com/ Tested-by: Marius Fleischer <fleischermarius@gmail.com> Tested-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge tag 'mm-stable-2024-03-13-20-04' of ↵Linus Torvalds2024-03-141-4/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames from hotplugged memory rather than only from main memory. Series "implement "memmap on memory" feature on s390". - More folio conversions from Matthew Wilcox in the series "Convert memcontrol charge moving to use folios" "mm: convert mm counter to take a folio" - Chengming Zhou has optimized zswap's rbtree locking, providing significant reductions in system time and modest but measurable reductions in overall runtimes. The series is "mm/zswap: optimize the scalability of zswap rb-tree". - Chengming Zhou has also provided the series "mm/zswap: optimize zswap lru list" which provides measurable runtime benefits in some swap-intensive situations. - And Chengming Zhou further optimizes zswap in the series "mm/zswap: optimize for dynamic zswap_pools". Measured improvements are modest. - zswap cleanups and simplifications from Yosry Ahmed in the series "mm: zswap: simplify zswap_swapoff()". - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has contributed several DAX cleanups as well as adding a sysfs tunable to control the memmap_on_memory setting when the dax device is hotplugged as system memory. - Johannes Weiner has added the large series "mm: zswap: cleanups", which does that. - More DAMON work from SeongJae Park in the series "mm/damon: make DAMON debugfs interface deprecation unignorable" "selftests/damon: add more tests for core functionalities and corner cases" "Docs/mm/damon: misc readability improvements" "mm/damon: let DAMOS feeds and tame/auto-tune itself" - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs extension" Rakie Kim has developed a new mempolicy interleaving policy wherein we allocate memory across nodes in a weighted fashion rather than uniformly. This is beneficial in heterogeneous memory environments appearing with CXL. - Christophe Leroy has contributed some cleanup and consolidation work against the ARM pagetable dumping code in the series "mm: ptdump: Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute". - Luis Chamberlain has added some additional xarray selftesting in the series "test_xarray: advanced API multi-index tests". - Muhammad Usama Anjum has reworked the selftest code to make its human-readable output conform to the TAP ("Test Anything Protocol") format. Amongst other things, this opens up the use of third-party tools to parse and process out selftesting results. - Ryan Roberts has added fork()-time PTE batching of THP ptes in the series "mm/memory: optimize fork() with PTE-mapped THP". Mainly targeted at arm64, this significantly speeds up fork() when the process has a large number of pte-mapped folios. - David Hildenbrand also gets in on the THP pte batching game in his series "mm/memory: optimize unmap/zap with PTE-mapped THP". It implements batching during munmap() and other pte teardown situations. The microbenchmark improvements are nice. - And in the series "Transparent Contiguous PTEs for User Mappings" Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte mappings"). Kernel build times on arm64 improved nicely. Ryan's series "Address some contpte nits" provides some followup work. - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has fixed an obscure hugetlb race which was causing unnecessary page faults. He has also added a reproducer under the selftest code. - In the series "selftests/mm: Output cleanups for the compaction test", Mark Brown did what the title claims. - Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring". - Even more zswap material from Nhat Pham. The series "fix and extend zswap kselftests" does as claimed. - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in our handling of DAX on archiecctures which have virtually aliasing data caches. The arm architecture is the main beneficiary. - Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic improvements in worst-case mmap_lock hold times during certain userfaultfd operations. - Some page_owner enhancements and maintenance work from Oscar Salvador in his series "page_owner: print stacks and their outstanding allocations" "page_owner: Fixup and cleanup" - Uladzislau Rezki has contributed some vmalloc scalability improvements in his series "Mitigate a vmap lock contention". It realizes a 12x improvement for a certain microbenchmark. - Some kexec/crash cleanup work from Baoquan He in the series "Split crash out from kexec and clean up related config items". - Some zsmalloc maintenance work from Chengming Zhou in the series "mm/zsmalloc: fix and optimize objects/page migration" "mm/zsmalloc: some cleanup for get/set_zspage_mapping()" - Zi Yan has taught the MM to perform compaction on folios larger than order=0. This a step along the path to implementaton of the merging of large anonymous folios. The series is named "Enable >0 order folio memory compaction". - Christoph Hellwig has done quite a lot of cleanup work in the pagecache writeback code in his series "convert write_cache_pages() to an iterator". - Some modest hugetlb cleanups and speedups in Vishal Moola's series "Handle hugetlb faults under the VMA lock". - Zi Yan has changed the page splitting code so we can split huge pages into sizes other than order-0 to better utilize large folios. The series is named "Split a folio to any lower order folios". - David Hildenbrand has contributed the series "mm: remove total_mapcount()", a cleanup. - Matthew Wilcox has sought to improve the performance of bulk memory freeing in his series "Rearrange batched folio freeing". - Gang Li's series "hugetlb: parallelize hugetlb page init on boot" provides large improvements in bootup times on large machines which are configured to use large numbers of hugetlb pages. - Matthew Wilcox's series "PageFlags cleanups" does that. - Qi Zheng's series "minor fixes and supplement for ptdesc" does that also. S390 is affected. - Cleanups to our pagemap utility functions from Peter Xu in his series "mm/treewide: Replace pXd_large() with pXd_leaf()". - Nico Pache has fixed a few things with our hugepage selftests in his series "selftests/mm: Improve Hugepage Test Handling in MM Selftests". - Also, of course, many singleton patches to many things. Please see the individual changelogs for details. * tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits) mm/zswap: remove the memcpy if acomp is not sleepable crypto: introduce: acomp_is_async to expose if comp drivers might sleep memtest: use {READ,WRITE}_ONCE in memory scanning mm: prohibit the last subpage from reusing the entire large folio mm: recover pud_leaf() definitions in nopmd case selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements selftests/mm: skip uffd hugetlb tests with insufficient hugepages selftests/mm: dont fail testsuite due to a lack of hugepages mm/huge_memory: skip invalid debugfs new_order input for folio split mm/huge_memory: check new folio order when split a folio mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure mm: add an explicit smp_wmb() to UFFDIO_CONTINUE mm: fix list corruption in put_pages_list mm: remove folio from deferred split list before uncharging it filemap: avoid unnecessary major faults in filemap_fault() mm,page_owner: drop unnecessary check mm,page_owner: check for null stack_record before bumping its refcount mm: swap: fix race between free_swap_and_cache() and swapoff() mm/treewide: align up pXd_leaf() retval across archs mm/treewide: drop pXd_large() ...
| * maple_tree: avoid duplicate variable init in mast_spanning_rebalance()Lukas Bulwahn2024-02-221-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The local variables r_tmp and l_tmp in mast_spanning_rebalance() are already initialized at its declaration; there is no need to assign the value again. Remove the duplicate initialization of {r,l}_tmp. No functional change. Due to common compiler optimizations, also no change to object code. This issue was identified with clang-analyzer's dead stores analysis. Link: https://lkml.kernel.org/r/20240122102000.29558-1-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * maple_tree: fix comment describing mas_node_count_gfp()Sidhartha Kumar2024-02-211-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The function description comment for mas_node_count_gfp() mistakingly refers to the function as mas_node_count(). Change it to refer to the correct function. Link: https://lkml.kernel.org/r/20240109223119.162357-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: Add mtree_alloc_cyclic()Chuck Lever2024-02-211-0/+93
|/ | | | | | | | | I need a cyclic allocator for the simple_offset implementation in fs/libfs.c. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Link: https://lore.kernel.org/r/170820144179.6328.12838600511394432325.stgit@91.116.238.104.host.secureserver.net Signed-off-by: Christian Brauner <brauner@kernel.org>
* maple_tree: avoid checking other gaps after getting the largest gapPeng Zhang2023-12-201-0/+3
| | | | | | | | | | | | | | The last range stored in maple tree is typically quite large. By checking if it exceeds the sum of the remaining ranges in that node, it is possible to avoid checking all other gaps. Running the maple tree test suite in user mode almost always results in a near 100% hit rate for this optimization. Link: https://lkml.kernel.org/r/20231215074632.82045-1-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* maple_tree: fix typos/spellos etcRandy Dunlap2023-12-201-4/+4
| | | | | | | | | | Fix typos/grammar and spellos in documentation. Link: https://lkml.kernel.org/r/20231210063839.29967-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* lib/maple_tree.c: fix build error due to hotfix alterationAndrew Morton2023-12-201-1/+1
| | | | | | | | | | | | | | Commit 0de56e38b307 ("maple_tree: use maple state end for write operations") was broken by a later patch "maple_tree: do not preallocate nodes for slot stores". But the later patch was scheduled ahead of 0de56e38b307, for 6.7-rc. This fixlet undoes the damage. Fixes: 0de56e38b307 ("maple_tree: use maple state end for write operations") Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* sync mm-stable with mm-hotfixes-stable to pick up depended-upon changesAndrew Morton2023-12-201-0/+11
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| * maple_tree: do not preallocate nodes for slot storesSidhartha Kumar2023-12-201-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mas_preallocate() defaults to requesting 1 node for preallocation and then ,depending on the type of store, will update the request variable. There isn't a check for a slot store type, so slot stores are preallocating the default 1 node. Slot stores do not require any additional nodes, so add a check for the slot store case that will bypass node_count_gfp(). Update the tests to reflect that slot stores do not require allocations. User visible effects of this bug include increased memory usage from the unneeded node that was allocated. Link: https://lkml.kernel.org/r/20231213205058.386589-1-sidhartha.kumar@oracle.com Fixes: 0b8bb544b1a7 ("maple_tree: update mas_preallocate() testing") Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Cc: <stable@vger.kernel.org> [6.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: change return type of mas_split_final_node as void.Levi Yun2023-12-121-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | mas_split_final_node() always returns true and its return value is never checked. Change return type to void. Link: https://lkml.kernel.org/r/20231109160821.16248-2-ppbuk5246@gmail.com Signed-off-by: Levi Yun <ppbuk5246@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: simplify mas_leaf_set_meta()Peng Zhang2023-12-121-18/+4
| | | | | | | | | | | | | | | | | | | | | | | | Now it seems that the incoming 'end' is already pointing to the last item, so we can simplify this function, considering only whether the last slot is being used. This has passed the maple tree test suite. Link: https://lkml.kernel.org/r/20231120070937.35481-6-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: delete one of the two identical checksPeng Zhang2023-12-121-3/+0
| | | | | | | | | | | | | | | | | | | | There are two identical checks, delete one of them. Link: https://lkml.kernel.org/r/20231120070937.35481-5-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: remove an unused parameter for ma_meta_end()Peng Zhang2023-12-121-6/+4
| | | | | | | | | | | | | | | | | | | | The parameter maple_type is not used, so remove it. Link: https://lkml.kernel.org/r/20231120070937.35481-4-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: avoid ascending when mas->min is also the parent's minimumPeng Zhang2023-12-121-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | When the child node is the first child of its parent node, mas->min does not need to be updated. This can reduce the number of ascending times in some cases. Link: https://lkml.kernel.org/r/20231120070937.35481-3-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: move the check forward to avoid static check warningPeng Zhang2023-12-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Some cleanups of maple tree", v2. These are some small cleanups of maple tree. This patch (of 5): Put the check for gap before its reference to avoid Smatch static check warnings. This is not a bug, it's just a validation program. Even with this change, Smatch may still generate warnings because MT_BUG_ON() doesn't necessarily stop the program. It may require fixing Smatch itself to avoid these warnings. Link: https://lkml.kernel.org/r/20231120070937.35481-1-zhangpeng.00@bytedance.com Link: https://lkml.kernel.org/r/20231120070937.35481-2-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: http://lists.infradead.org/pipermail/maple-tree/2023-November/003046.html Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: remove unused functionJiapeng Chong2023-12-121-29/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function are defined in the maple_tree.c file, but not called elsewhere, so delete the unused function. lib/maple_tree.c:689:29: warning: unused function 'mas_pivot'. Link: https://lkml.kernel.org/r/20231027084944.24888-1-jiapeng.chong@linux.alibaba.com Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Reported-by: Abaci Robot <abaci@linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=7064 Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: mtree_range_walk() clean upLiam R. Howlett2023-12-121-15/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mtree_range_walk() needed to be updated to avoid checking if there was a pivot value. On closer examination, the code could avoid setting min or max in certain scenarios. The commit removes the extra check for pivot[offset] before setting max and only sets max when necessary. It also only sets min if it is necessary by checking offset 0 prior to the loop (as it has always done). The commit also drops a dead node check since the end of the node will return the array size when the last slot is occupied (by a potential reuse in a dead node). The data will be discarded later if the node is marked dead. Benchmarking these changes results in an increase in performance of 5.45% using the BENCH_WALK in the maple tree test code. Link: https://lkml.kernel.org/r/20231101171629.3612299-13-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: don't find node end in mtree_lookup_walk()Liam R. Howlett2023-12-121-9/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the pivot being set is now reliable, the optimized loop no longer needs to find the node end. The redundant check for a dead node can also be avoided as there is no danger of using the wrong pivot since the results will be thrown out in the case of a dead node by the later check. This patch also adds a benchmark test for the function to the maple tree test framework. The benchmark shows an average increase performance of 5.98% over 3 runs with this commit. Link: https://lkml.kernel.org/r/20231101171629.3612299-12-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: use maple state end for write operationsLiam R. Howlett2023-12-121-22/+24
| | | | | | | | | | | | | | | | | | | | | | | | ma_wr_state was previously tracking the end of the node for writing. Since the implementation of the ma_state end tracking, this is duplicated work. This patch removes the maple write state tracking of the end of the node and uses the maple state end instead. Link: https://lkml.kernel.org/r/20231101171629.3612299-11-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: remove mas_searchable()Liam R. Howlett2023-12-121-50/+16
| | | | | | | | | | | | | | | | | | | | | | Now that the status of the maple state is outside of the node, the mas_searchable() function can be dropped for easier open-coding of what is going on. Link: https://lkml.kernel.org/r/20231101171629.3612299-10-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: separate ma_state node from statusLiam R. Howlett2023-12-121-183/+276
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The maple tree node is overloaded to keep status as well as the active node. This, unfortunately, results in a re-walk on underflow or overflow. Since the maple state has room, the status can be placed in its own enum in the structure. Once an underflow/overflow is detected, certain modes can restore the status to active and others may need to re-walk just that one node to see the entry. The status being an enum has the benefit of detecting unhandled status in switch statements. [Liam.Howlett@oracle.com: fix comments about MAS_*] Link: https://lkml.kernel.org/r/20231106154124.614247-1-Liam.Howlett@oracle.com [Liam.Howlett@oracle.com: update forking to separate maple state and node] Link: https://lkml.kernel.org/r/20231106154551.615042-1-Liam.Howlett@oracle.com [Liam.Howlett@oracle.com: fix mas_prev() state separation code] Link: https://lkml.kernel.org/r/20231207193319.4025462-1-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20231101171629.3612299-9-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: clean up inlines for some functionsLiam R. Howlett2023-12-121-39/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a few functions which were inlined but are somewhat too large to inline, so remove the inline key word. There are also several very small functions which are used in critical code sections which gcc was not inlining, so make this more strict and use __always_line for these functions. Link: https://lkml.kernel.org/r/20231101171629.3612299-8-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: use cached node end in mas_destroy()Liam R. Howlett2023-12-121-1/+1
| | | | | | | | | | | | | | | | | | | | The node end is set during the walk, so use the resulting end instead of re-fetching it. Link: https://lkml.kernel.org/r/20231101171629.3612299-7-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: use cached node end in mas_next()Liam R. Howlett2023-12-121-6/+8
| | | | | | | | | | | | | | | | | | | | When looking for the next entry, don't recalculate the node end as it is now tracked in the maple state. Link: https://lkml.kernel.org/r/20231101171629.3612299-6-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: add end of node tracking to the maple stateLiam R. Howlett2023-12-121-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | Analysis of the mas_for_each() iteration showed that there is a significant time spent finding the end of a node. This time can be greatly reduced if the end of the node is cached in the maple state. Care must be taken to update & invalidate as necessary. Link: https://lkml.kernel.org/r/20231101171629.3612299-5-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: make mas_erase() more robustLiam R. Howlett2023-12-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | mas_erase() may not deal correctly with all maple states. Make the function more robust by ensuring the state is in one of the two acceptable states. Link: https://lkml.kernel.org/r/20231101171629.3612299-3-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: remove unnecessary default labels from switch statementsLiam R. Howlett2023-12-121-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "maple_tree: iterator state changes". These patches have some general cleanup and a change to separate the maple state status tracking from the maple state node. The maple state status change allows for walks to continue from previous places when the status needs to be recorded to make logical sense for the next call to the maple state. For instance, it allows for prev/next to function in a way that better resembles the linked list. It also allows switch statements to be used to detect missed states during compile, and the addition of fast-path "active" state is cleaner as an enum. While making the status change, perf showed some very small (one line) functions that were not inlined even with the inline key word. Making these small functions __always_inline is less expensive according to perf. As part of that change, some inlines have been dropped from larger functions. Perf also showed that the commonly used mas_for_each() iterator was spending a lot of time finding the end of the node. This series introduces caching of the end of the node in the maple state (and updating it during writes). This caching along with the inline changes yielded at 23.25% improvement on the BENCH_MAS_FOR_EACH maple tree test framework benchmark. I've also included a change to mtree_range_walk and mtree_lookup_walk to take advantage of Peng's change [1] to the initial pivot setup. mmtests did not produce any significant gains. [1] https://lore.kernel.org/all/20230711035444.526-1-zhangpeng.00@bytedance.com/T/#u This patch (of 12): Removing the default types from the switch statements will cause compile warnings on missing cases. Link: https://lkml.kernel.org/r/20231101171629.3612299-2-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: preserve the tree attributes when destroying maple treePeng Zhang2023-12-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When destroying maple tree, preserve its attributes and then turn it into an empty tree. This allows it to be reused without needing to be reinitialized. Link: https://lkml.kernel.org/r/20231027033845.90608-10-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Mike Christie <michael.christie@oracle.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: introduce interfaces __mt_dup() and mtree_dup()Peng Zhang2023-12-101-0/+274
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce interfaces __mt_dup() and mtree_dup(), which are used to duplicate a maple tree. They duplicate a maple tree in Depth-First Search (DFS) pre-order traversal. It uses memcopy() to copy nodes in the source tree and allocate new child nodes in non-leaf nodes. The new node is exactly the same as the source node except for all the addresses stored in it. It will be faster than traversing all elements in the source tree and inserting them one by one into the new tree. The time complexity of these two functions is O(n). The difference between __mt_dup() and mtree_dup() is that mtree_dup() handles locks internally. Analysis of the average time complexity of this algorithm: For simplicity, let's assume that the maximum branching factor of all non-leaf nodes is 16 (in allocation mode, it is 10), and the tree is a full tree. Under the given conditions, if there is a maple tree with n elements, the number of its leaves is n/16. From bottom to top, the number of nodes in each level is 1/16 of the number of nodes in the level below. So the total number of nodes in the entire tree is given by the sum of n/16 + n/16^2 + n/16^3 + ... + 1. This is a geometric series, and it has log(n) terms with base 16. According to the formula for the sum of a geometric series, the sum of this series can be calculated as (n-1)/15. Each node has only one parent node pointer, which can be considered as an edge. In total, there are (n-1)/15-1 edges. This algorithm consists of two operations: 1. Traversing all nodes in DFS order. 2. For each node, making a copy and performing necessary modifications to create a new node. For the first part, DFS traversal will visit each edge twice. Let T(ascend) represent the cost of taking one step downwards, and T(descend) represent the cost of taking one step upwards. And both of them are constants (although mas_ascend() may not be, as it contains a loop, but here we ignore it and treat it as a constant). So the time spent on the first part can be represented as ((n-1)/15-1) * (T(ascend) + T(descend)). For the second part, each node will be copied, and the cost of copying a node is denoted as T(copy_node). For each non-leaf node, it is necessary to reallocate all child nodes, and the cost of this operation is denoted as T(dup_alloc). The behavior behind memory allocation is complex and not specific to the maple tree operation. Here, we assume that the time required for a single allocation is constant. Since the size of a node is fixed, both of these symbols are also constants. We can calculate that the time spent on the second part is ((n-1)/15) * T(copy_node) + ((n-1)/15 - n/16) * T(dup_alloc). Adding both parts together, the total time spent by the algorithm can be represented as: ((n-1)/15) * (T(ascend) + T(descend) + T(copy_node) + T(dup_alloc)) - n/16 * T(dup_alloc) - (T(ascend) + T(descend)) Let C1 = T(ascend) + T(descend) + T(copy_node) + T(dup_alloc) Let C2 = T(dup_alloc) Let C3 = T(ascend) + T(descend) Finally, the expression can be simplified as: ((16 * C1 - 15 * C2) / (15 * 16)) * n - (C1 / 15 + C3). This is a linear function, so the average time complexity is O(n). Link: https://lkml.kernel.org/r/20231027033845.90608-4-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Suggested-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Mike Christie <michael.christie@oracle.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: add mt_free_one() and mt_attr() helpersPeng Zhang2023-12-101-1/+11
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Introduce __mt_dup() to improve the performance of fork()", v7. This series introduces __mt_dup() to improve the performance of fork(). During the duplication process of mmap, all VMAs are traversed and inserted one by one into the new maple tree, causing the maple tree to be rebalanced multiple times. Balancing the maple tree is a costly operation. To duplicate VMAs more efficiently, mtree_dup() and __mt_dup() are introduced for the maple tree. They can efficiently duplicate a maple tree. Here are some algorithmic details about {mtree,__mt}_dup(). We perform a DFS pre-order traversal of all nodes in the source maple tree. During this process, we fully copy the nodes from the source tree to the new tree. This involves memory allocation, and when encountering a new node, if it is a non-leaf node, all its child nodes are allocated at once. This idea was originally from Liam R. Howlett's Maple Tree Work email, and I added some of my own ideas to implement it. Some previous discussions can be found in [1]. For a more detailed analysis of the algorithm, please refer to the logs for patch [3/10] and patch [10/10]. There is a "spawn" in byte-unixbench[2], which can be used to test the performance of fork(). I modified it slightly to make it work with different number of VMAs. Below are the test results. The first row shows the number of VMAs. The second and third rows show the number of fork() calls per ten seconds, corresponding to next-20231006 and the this patchset, respectively. The test results were obtained with CPU binding to avoid scheduler load balancing that could cause unstable results. There are still some fluctuations in the test results, but at least they are better than the original performance. 21 121 221 421 821 1621 3221 6421 12821 25621 51221 112100 76261 54227 34035 20195 11112 6017 3161 1606 802 393 114558 83067 65008 45824 28751 16072 8922 4747 2436 1233 599 2.19% 8.92% 19.88% 34.64% 42.37% 44.64% 48.28% 50.17% 51.68% 53.74% 52.42% Thanks to Liam and Matthew for the review. This patch (of 10): Add two helpers: 1. mt_free_one(), used to free a maple node. 2. mt_attr(), used to obtain the attributes of maple tree. Link: https://lkml.kernel.org/r/20231027033845.90608-1-zhangpeng.00@bytedance.com Link: https://lkml.kernel.org/r/20231027033845.90608-2-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Mike Christie <michael.christie@oracle.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* maple_tree: add GFP_KERNEL to allocations in mas_expected_entries()Liam R. Howlett2023-10-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Users complained about OOM errors during fork without triggering compaction. This can be fixed by modifying the flags used in mas_expected_entries() so that the compaction will be triggered in low memory situations. Since mas_expected_entries() is only used during fork, the extra argument does not need to be passed through. Additionally, the two test_maple_tree test cases and one benchmark test were altered to use the correct locking type so that allocations would not trigger sleeping and thus fail. Testing was completed with lockdep atomic sleep detection. The additional locking change requires rwsem support additions to the tools/ directory through the use of pthreads pthread_rwlock_t. With this change test_maple_tree works in userspace, as a module, and in-kernel. Users may notice that the system gave up early on attempting to start new processes instead of attempting to reclaim memory. Link: https://lkml.kernel.org/r/20230915093243epcms1p46fa00bbac1ab7b7dca94acb66c44c456@epcms1p4 Link: https://lkml.kernel.org/r/20231012155233.2272446-1-Liam.Howlett@oracle.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Peng Zhang <zhangpeng.00@bytedance.com> Cc: <jason.sim@samsung.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* maple_tree: add MAS_UNDERFLOW and MAS_OVERFLOW statesLiam R. Howlett2023-09-291-58/+163
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When updating the maple tree iterator to avoid rewalks, an issue was introduced when shifting beyond the limits. This can be seen by trying to go to the previous address of 0, which would set the maple node to MAS_NONE and keep the range as the last entry. Subsequent calls to mas_find() would then search upwards from mas->last and skip the value at mas->index/mas->last. This showed up as a bug in mprotect which skips the actual VMA at the current range after attempting to go to the previous VMA from 0. Since MAS_NONE may already be set when searching for a value that isn't contained within a node, changing the handling of MAS_NONE in mas_find() would make the code more complicated and error prone. Furthermore, there was no way to tell which limit was hit, and thus which action to take (next or the entry at the current range). This solution is to add two states to track what happened with the previous iterator action. This allows for the expected behaviour of the next command to return the correct item (either the item at the range requested, or the next/previous). Tests are also added and updated accordingly. Link: https://lkml.kernel.org/r/20230921181236.509072-3-Liam.Howlett@oracle.com Link: https://gist.github.com/heatd/85d2971fae1501b55b6ea401fbbe485b Link: https://lore.kernel.org/linux-mm/20230921181236.509072-1-Liam.Howlett@oracle.com/ Fixes: 39193685d585 ("maple_tree: try harder to keep active node with mas_prev()") Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reported-by: Pedro Falcato <pedro.falcato@gmail.com> Closes: https://gist.github.com/heatd/85d2971fae1501b55b6ea401fbbe485b Closes: https://bugs.archlinux.org/task/79656 Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* maple_tree: clean up mas_wr_append()Liam R. Howlett2023-08-241-14/+20
| | | | | | | | | | | | | | | | | Avoid setting the variables until necessary, and actually use the variables where applicable. Introducing a variable for the slots array avoids spanning multiple lines. Add the missing argument to the documentation. Use the node type when setting the metadata instead of blindly assuming the type. Finally, add a trace point to the function for successful store. Link: https://lkml.kernel.org/r/20230819004356.1454718-3-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* merge mm-hotfixes-stable into mm-stable to pick up depended-upon changesAndrew Morton2023-08-241-0/+7
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| * maple_tree: disable mas_wr_append() when other readers are possibleLiam R. Howlett2023-08-241-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current implementation of append may cause duplicate data and/or incorrect ranges to be returned to a reader during an update. Although this has not been reported or seen, disable the append write operation while the tree is in rcu mode out of an abundance of caution. During the analysis of the mas_next_slot() the following was artificially created by separating the writer and reader code: Writer: reader: mas_wr_append set end pivot updates end metata Detects write to last slot last slot write is to start of slot store current contents in slot overwrite old end pivot mas_next_slot(): read end metadata read old end pivot return with incorrect range store new value Alternatively: Writer: reader: mas_wr_append set end pivot updates end metata Detects write to last slot last lost write to end of slot store value mas_next_slot(): read end metadata read old end pivot read new end pivot return with incorrect range set old end pivot There may be other accesses that are not safe since we are now updating both metadata and pointers, so disabling append if there could be rcu readers is the safest action. Link: https://lkml.kernel.org/r/20230819004356.1454718-2-Liam.Howlett@oracle.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: replace data before marking dead in split and spanning storeLiam R. Howlett2023-08-211-325/+168
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reorder the operations for split and spanning stores so that new data is placed in the tree prior to marking the old data as dead. This will limit re-walks on dead data to just once instead of a retry loop. The order of operations is as follows: Create the new data, put the new data in place, mark the top node of the old data as dead. Then repair parent links in the reused nodes through all levels of the tree, following the new nodes downwards. Finally walk the top dead node looking for nodes that are no longer used, or subtrees that should be destroyed (marked dead throughout then freed), follow the partially used nodes downwards to discover other dead nodes and subtrees. Link: https://lkml.kernel.org/r/20230804165951.2661157-7-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: change mas_adopt_children() parent usageLiam R. Howlett2023-08-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | All calls to mas_adopt_children() currently pass the parent as the node in the maple state. Allow for the parent pointer that is passed in to be used instead. Link: https://lkml.kernel.org/r/20230804165951.2661157-6-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: introduce mas_tree_parent() definitionLiam R. Howlett2023-08-211-8/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Add a definition to shorten long code lines and clarify what the code is doing. Use the new definition to get the maple tree parent pointer from the maple state where possible. Link: https://lkml.kernel.org/r/20230804165951.2661157-5-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: introduce mas_put_in_tree()Liam R. Howlett2023-08-211-46/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | mas_replace() has a single user that takes a flag which is now always true. Replace this function with mas_put_in_tree() to better align with mas_replace_node(). Inline the remaining logic into the only caller; mas_wmb_replace(). Link: https://lkml.kernel.org/r/20230804165951.2661157-4-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: reorder replacement of nodes to avoid live lockLiam R. Howlett2023-08-211-10/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replacing nodes may cause a live lock-up if CPU resources are saturated by write operations on the tree by continuously retrying on dead nodes. To avoid the continuous retry scenario, ensure the new node is inserted into the tree prior to marking the old data as dead. This will define a window where old and new data is swapped. When reusing lower level nodes, ensure the parent pointer is updated after the parent is marked dead. This ensures that the child is still reachable from the top of the tree, but walking up to a dead node will result in a single retry that will start a fresh walk from the top down through the new node. Link: https://lkml.kernel.org/r/20230804165951.2661157-3-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: add hex output to maple_arange64 dumpLiam R. Howlett2023-08-211-4/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "maple_tree: Change replacement strategy". The maple tree marks nodes dead as soon as they are going to be replaced. This could be problematic when used in the RCU context since the writer may be starved of CPU time by the readers. This patch set addresses the issue by switching the data replacement strategy to one that will only mark data as dead once the new data is available. This series changes the ordering of the node replacement so that the new data is live before the old data is marked 'dead'. When readers hit 'dead' nodes, they will restart from the top of the tree and end up in the new data. In more complex scenarios, the replacement strategy means a subtree is built and graphed into the tree leaving some nodes to point to the old parent. The view of tasks into the old data will either remain with the old data, or see the new data once the old data is marked 'dead'. Iterators will see the 'dead' node and restart on their own and switch to the new data. There is no risk of the reader seeing old data in these cases. The 'dead' subtree of data is then fully marked dead, but reused nodes will still point to the dead nodes until the parent pointer is updated. Walking up to a 'dead' node will cause a re-walk from the top of the tree and enter the new data area where old data is not reachable. Once the parent pointers are fully up to date in the active data, the 'dead' subtree is iterated to collect entirely 'dead' subtrees, and dead nodes (nodes that partially contained reused data). This patch (of 6): When dumping the tree, honour formatting request to output hex for the maple node type arange64. Link: https://lkml.kernel.org/r/20230804165951.2661157-1-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20230804165951.2661157-2-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: reduce resets during store setupLiam R. Howlett2023-08-181-11/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | mas_prealloc() may walk partially down the tree before finding that a split or spanning store is needed. When the write occurs, relax the logic on resetting the walk so that partial walks will not restart, but walks that have gone too far (a store that affects beyond the current node) should be restarted. Link: https://lkml.kernel.org/r/20230724183157.3939892-15-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: refine mas_preallocate() node calculationsLiam R. Howlett2023-08-181-1/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Calculate the number of nodes based on the pending write action instead of assuming the worst case. This addresses a performance regression introduced in platforms that have longer allocation timing. Link: https://lkml.kernel.org/r/20230724183157.3939892-14-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: move mas_wr_end_piv() below mas_wr_extend_null()Liam R. Howlett2023-08-181-16/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | Relocate it and call mas_wr_extend_null() from within mas_wr_end_piv(). Extending the NULL may affect the end pivot value so call mas_wr_endtend_null() from within mas_wr_end_piv() to keep it all together. Link: https://lkml.kernel.org/r/20230724183157.3939892-12-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: adjust node allocation on mas_rebalance()Liam R. Howlett2023-08-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | mas_rebalance() is called to rebalance an insufficient node into a single node or two sufficient nodes. The preallocation estimate is always too many in this case as the height of the tree will never grow and there is no possibility to have a three way split in this case, so revise the node allocation count. Link: https://lkml.kernel.org/r/20230724183157.3939892-9-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: re-introduce entry to mas_preallocate() argumentsLiam R. Howlett2023-08-181-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The current preallocation strategy is to preallocate the absolute worst-case allocation for a tree modification. The entry (or NULL) is needed to know how many nodes are needed to write to the tree. Start by adding the argument to the mas_preallocate() definition. Link: https://lkml.kernel.org/r/20230724183157.3939892-8-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: Be more strict about lockingLiam R. Howlett2023-08-181-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use lockdep to check the write path in the maple tree holds the lock in write mode. Introduce mt_write_lock_is_held() to check if the lock is held for writing. Update the necessary checks for rcu_dereference_protected() to use the new write lock check. Link: https://lkml.kernel.org/r/20230714195551.894800-5-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oliver Sang <oliver.sang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: mtree_insert: fix typo in kernel-doc description of GFP flagsMike Rapoport (IBM)2023-08-181-1/+1
| | | | | | | | | | | | | | | | | | Replace FGP_FLAGS with GFP_FLAGS Link: https://lkml.kernel.org/r/20230715084038.987955-1-rppt@kernel.org Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | maple_tree: mtree_insert*: fix typo in kernel-doc descriptionMike Rapoport (IBM)2023-08-181-2/+2
| | | | | | | | | | | | | | | | | | | | Replace "Insert and entry at a give index" with "Insert an entry at a given index" Link: https://lkml.kernel.org/r/20230715143920.994812-1-rppt@kernel.org Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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