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* mm: fix typos in commentsIngo Molnar2021-05-071-1/+1
| | | | | | | | | | | | | | Fix ~94 single-word typos in locking code comments, plus a few very obvious grammar mistakes. Link: https://lkml.kernel.org/r/20210322212624.GA1963421@gmail.com Link: https://lore.kernel.org/r/20210322205203.GB1959563@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/mempool: minor coding style tweaksZhiyuan Dai2021-05-051-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various coding style tweaks to various files under mm/ [daizhiyuan@phytium.com.cn: mm/swapfile: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614223624-16055-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/sparse: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614227288-19363-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/vmscan: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614227649-19853-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/compaction: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228218-20770-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/oom_kill: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228360-21168-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/shmem: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228504-21491-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/page_alloc: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228613-21754-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/filemap: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228936-22337-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/mlock: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613956588-2453-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/frontswap: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613962668-15045-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/vmalloc: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613963379-15988-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/memory_hotplug: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613971784-24878-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/mempolicy: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613972228-25501-1-git-send-email-daizhiyuan@phytium.com.cn Link: https://lkml.kernel.org/r/1614222374-13805-1-git-send-email-daizhiyuan@phytium.com.cn Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dax: account DAX entries as nrpagesMatthew Wilcox (Oracle)2021-05-051-3/+0
| | | | | | | | | | | | Simplify mapping_needs_writeback() by accounting DAX entries as pages instead of exceptional entries. Link: https://lkml.kernel.org/r/20201026151849.24232-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Vishal Verma <vishal.l.verma@intel.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: stop accounting shadow entriesMatthew Wilcox (Oracle)2021-05-051-13/+0
| | | | | | | | | | | | We no longer need to keep track of how many shadow entries are present in a mapping. This saves a few writes to the inode and memory barriers. Link: https://lkml.kernel.org/r/20201026151849.24232-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Vishal Verma <vishal.l.verma@intel.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: update stale commentRui Sun2021-04-301-1/+1
| | | | | | | | | | | | Commit a6de4b4873e1 ("mm: convert find_get_entry to return the head page") uses @index instead of @offset, but the comment is stale, update it. Link: https://lkml.kernel.org/r/1617948260-50724-1-git-send-email-zhangshaokun@hisilicon.com Signed-off-by: Rui Sun <sunrui26@huawei.com> Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: drop check for truncated page after I/OMatthew Wilcox (Oracle)2021-04-301-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | If the I/O completed successfully, the page will remain Uptodate, even if it is subsequently truncated. If the I/O completed with an error, this check would cause us to retry the I/O if the page were truncated before we woke up. There is no need to retry the I/O; the I/O to fill the page failed, so we can legitimately just return -EIO. This code was originally added by commit 56f0d5fe6851 ("[PATCH] readpage-vs-invalidate fix") in 2005 (this commit ID is from the linux-fullhistory tree; it is also commit ba1f08f14b52 in tglx-history). At the time, truncate_complete_page() called ClearPageUptodate(), and so this was fixing a real bug. In 2008, commit 84209e02de48 ("mm: dont clear PG_uptodate on truncate/invalidate") removed the call to ClearPageUptodate, and this check has been unnecessary ever since. It doesn't do any real harm, but there's no need to keep it. Link: https://lkml.kernel.org/r/20210303222547.1056428-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: William Kucharski <william.kucharski@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: use filemap_read_page in filemap_faultMatthew Wilcox (Oracle)2021-04-301-9/+1
| | | | | | | | | | | | | | | | | | | | | After splitting generic_file_buffered_read() into smaller parts, it turns out we can reuse one of the parts in filemap_fault(). This fixes an oversight -- waiting for the I/O to complete is now interruptible by a fatal signal. And it saves us a few bytes of text in an unlikely path. $ ./scripts/bloat-o-meter before.o after.o add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-207 (-207) Function old new delta filemap_fault 2187 1980 -207 Total: Before=37491, After=37284, chg -0.55% Link: https://lkml.kernel.org/r/20210226140011.2883498-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: use filemap_range_needs_writeback() for O_DIRECT readsJens Axboe2021-04-301-2/+2
| | | | | | | | | | | | | | For the generic page cache read helper, use the better variant of checking for the need to call filemap_write_and_wait_range() when doing O_DIRECT reads. This avoids falling back to the slow path for IOCB_NOWAIT, if there are no pages to wait for (or write out). Link: https://lkml.kernel.org/r/20210224164455.1096727-3-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: provide filemap_range_needs_writeback() helperJens Axboe2021-04-301-0/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Improve IOCB_NOWAIT O_DIRECT reads", v3. An internal workload complained because it was using too much CPU, and when I took a look, we had a lot of io_uring workers going to town. For an async buffered read like workload, I am normally expecting _zero_ offloads to a worker thread, but this one had tons of them. I'd drop caches and things would look good again, but then a minute later we'd regress back to using workers. Turns out that every minute something was reading parts of the device, which would add page cache for that inode. I put patches like these in for our kernel, and the problem was solved. Don't -EAGAIN IOCB_NOWAIT dio reads just because we have page cache entries for the given range. This causes unnecessary work from the callers side, when the IO could have been issued totally fine without blocking on writeback when there is none. This patch (of 3): For O_DIRECT reads/writes, we check if we need to issue a call to filemap_write_and_wait_range() to issue and/or wait for writeback for any page in the given range. The existing mechanism just checks for a page in the range, which is suboptimal for IOCB_NOWAIT as we'll fallback to the slow path (and needing retry) if there's just a clean page cache page in the range. Provide filemap_range_needs_writeback() which tries a little harder to check if we actually need to issue and/or wait for writeback in the range. Link: https://lkml.kernel.org/r/20210224164455.1096727-1-axboe@kernel.dk Link: https://lkml.kernel.org/r/20210224164455.1096727-2-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'netfs-lib-20210426' of ↵Linus Torvalds2021-04-271-2/+63
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull network filesystem helper library updates from David Howells: "Here's a set of patches for 5.13 to begin the process of overhauling the local caching API for network filesystems. This set consists of two parts: (1) Add a helper library to handle the new VM readahead interface. This is intended to be used unconditionally by the filesystem (whether or not caching is enabled) and provides a common framework for doing caching, transparent huge pages and, in the future, possibly fscrypt and read bandwidth maximisation. It also allows the netfs and the cache to align, expand and slice up a read request from the VM in various ways; the netfs need only provide a function to read a stretch of data to the pagecache and the helper takes care of the rest. (2) Add an alternative fscache/cachfiles I/O API that uses the kiocb facility to do async DIO to transfer data to/from the netfs's pages, rather than using readpage with wait queue snooping on one side and vfs_write() on the other. It also uses less memory, since it doesn't do buffered I/O on the backing file. Note that this uses SEEK_HOLE/SEEK_DATA to locate the data available to be read from the cache. Whilst this is an improvement from the bmap interface, it still has a problem with regard to a modern extent-based filesystem inserting or removing bridging blocks of zeros. Fixing that requires a much greater overhaul. This is a step towards overhauling the fscache API. The change is opt-in on the part of the network filesystem. A netfs should not try to mix the old and the new API because of conflicting ways of handling pages and the PG_fscache page flag and because it would be mixing DIO with buffered I/O. Further, the helper library can't be used with the old API. This does not change any of the fscache cookie handling APIs or the way invalidation is done at this time. In the near term, I intend to deprecate and remove the old I/O API (fscache_allocate_page{,s}(), fscache_read_or_alloc_page{,s}(), fscache_write_page() and fscache_uncache_page()) and eventually replace most of fscache/cachefiles with something simpler and easier to follow. This patchset contains the following parts: - Some helper patches, including provision of an ITER_XARRAY iov iterator and a function to do readahead expansion. - Patches to add the netfs helper library. - A patch to add the fscache/cachefiles kiocb API. - A pair of patches to fix some review issues in the ITER_XARRAY and read helpers as spotted by Al and Willy. Jeff Layton has patches to add support in Ceph for this that he intends for this merge window. I have a set of patches to support AFS that I will post a separate pull request for. With this, AFS without a cache passes all expected xfstests; with a cache, there's an extra failure, but that's also there before these patches. Fixing that probably requires a greater overhaul. Ceph also passes the expected tests. I also have patches in a separate branch to tidy up the handling of PG_fscache/PG_private_2 and their contribution to page refcounting in the core kernel here, but I haven't included them in this set and will route them separately" Link: https://lore.kernel.org/lkml/3779937.1619478404@warthog.procyon.org.uk/ * tag 'netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: netfs: Miscellaneous fixes iov_iter: Four fixes for ITER_XARRAY fscache, cachefiles: Add alternate API to use kiocb for read/write to cache netfs: Add a tracepoint to log failures that would be otherwise unseen netfs: Define an interface to talk to a cache netfs: Add write_begin helper netfs: Gather stats netfs: Add tracepoints netfs: Provide readahead and readpage netfs helpers netfs, mm: Add set/end/wait_on_page_fscache() aliases netfs, mm: Move PG_fscache helper funcs to linux/netfs.h netfs: Documentation for helper library netfs: Make a netfs helper module mm: Implement readahead_control pageset expansion mm/readahead: Handle ractl nr_pages being modified fs: Document file_ra_state mm/filemap: Pass the file_ra_state in the ractl mm: Add set/end/wait functions for PG_private_2 iov_iter: Add ITER_XARRAY
| * mm/filemap: Pass the file_ra_state in the ractlMatthew Wilcox (Oracle)2021-04-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | For readahead_expand(), we need to modify the file ra_state, so pass it down by adding it to the ractl. We have to do this because it's not always the same as f_ra in the struct file that is already being passed. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Jeff Layton <jlayton@kernel.org> Tested-by: Dave Wysochanski <dwysocha@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> Link: https://lore.kernel.org/r/20210407201857.3582797-2-willy@infradead.org/ Link: https://lore.kernel.org/r/161789067431.6155.8063840447229665720.stgit@warthog.procyon.org.uk/ # v6
| * mm: Add set/end/wait functions for PG_private_2David Howells2021-04-231-0/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add three functions to manipulate PG_private_2: (*) set_page_private_2() - Set the flag and take an appropriate reference on the flagged page. (*) end_page_private_2() - Clear the flag, drop the reference and wake up any waiters, somewhat analogously with end_page_writeback(). (*) wait_on_page_private_2() - Wait for the flag to be cleared. Wrappers will need to be placed in the netfs lib header in the patch that adds that. [This implements a suggestion by Linus[1] to not mix the terminology of PG_private_2 and PG_fscache in the mm core function] Changes: v7: - Use compound_head() in all the functions to make them THP safe[6]. v5: - Add set and end functions, calling the end function end rather than unlock[3]. - Keep a ref on the page when PG_private_2 is set[4][5]. v4: - Remove extern from the declaration[2]. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Jeff Layton <jlayton@kernel.org> Tested-by: Dave Wysochanski <dwysocha@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: Alexander Viro <viro@zeniv.linux.org.uk> cc: Christoph Hellwig <hch@lst.de> cc: linux-mm@kvack.org cc: linux-cachefs@redhat.com cc: linux-afs@lists.infradead.org cc: linux-nfs@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: ceph-devel@vger.kernel.org cc: v9fs-developer@lists.sourceforge.net cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/1330473.1612974547@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/CAHk-=wjgA-74ddehziVk=XAEMTKswPu1Yw4uaro1R3ibs27ztw@mail.gmail.com/ [1] Link: https://lore.kernel.org/r/20210216102659.GA27714@lst.de/ [2] Link: https://lore.kernel.org/r/161340387944.1303470.7944159520278177652.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539528910.286939.1252328699383291173.stgit@warthog.procyon.org.uk # v4 Link: https://lore.kernel.org/r/20210321105309.GG3420@casper.infradead.org [3] Link: https://lore.kernel.org/r/CAHk-=wh+2gbF7XEjYc=HV9w_2uVzVf7vs60BPz0gFA=+pUm3ww@mail.gmail.com/ [4] Link: https://lore.kernel.org/r/CAHk-=wjSGsRj7xwhSMQ6dAQiz53xA39pOG+XA_WeTgwBBu4uqg@mail.gmail.com/ [5] Link: https://lore.kernel.org/r/20210408145057.GN2531743@casper.infradead.org/ [6] Link: https://lore.kernel.org/r/161653788200.2770958.9517755716374927208.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789066013.6155.9816857201817288382.stgit@warthog.procyon.org.uk/ # v6
* | mm/filemap: fix mapping_seek_hole_data on THP & 32-bitHugh Dickins2021-04-231-10/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No problem on 64-bit, or without huge pages, but xfstests generic/285 and other SEEK_HOLE/SEEK_DATA tests have regressed on huge tmpfs, and on 32-bit architectures, with the new mapping_seek_hole_data(). Several different bugs turned out to need fixing. u64 cast to stop losing bits when converting unsigned long to loff_t (and let's use shifts throughout, rather than mixed with * and /). Use round_up() when advancing pos, to stop assuming that pos was already THP-aligned when advancing it by THP-size. (This use of round_up() assumes that any THP has THP-aligned index: true at present and true going forward, but could be recoded to avoid the assumption.) Use xas_set() when iterating away from a THP, so that xa_index stays in synch with start, instead of drifting away to return bogus offset. Check start against end to avoid wrapping 32-bit xa_index to 0 (and to handle these additional cases, seek_data or not, it's easier to break the loop than goto: so rearrange exit from the function). [hughd@google.com: remove unneeded u64 casts, per Matthew] Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2104221347240.1170@eggly.anvils Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2104211737410.3299@eggly.anvils Fixes: 41139aa4c3a3 ("mm/filemap: add mapping_seek_hole_data") Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/filemap: fix find_lock_entries hang on 32-bit THPHugh Dickins2021-04-231-2/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | No problem on 64-bit, or without huge pages, but xfstests generic/308 hung uninterruptibly on 32-bit huge tmpfs. Since commit 0cc3b0ec23ce ("Clarify (and fix) in 4.13 MAX_LFS_FILESIZE macros"), MAX_LFS_FILESIZE is only a PAGE_SIZE away from wrapping 32-bit xa_index to 0, so the new find_lock_entries() has to be extra careful when handling a THP. Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2104211735430.3299@eggly.anvils Fixes: 5c211ba29deb ("mm: add and use find_lock_entries") Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <dchinner@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: pass pvec directly to find_get_entriesMatthew Wilcox (Oracle)2021-02-261-12/+9
| | | | | | | | | | | | | | | | | | All callers of find_get_entries() use a pvec, so pass it directly instead of manipulating it in the caller. Link: https://lkml.kernel.org/r/20201112212641.27837-14-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: add an 'end' parameter to find_get_entriesMatthew Wilcox (Oracle)2021-02-261-4/+5
| | | | | | | | | | | | | | | | | | This simplifies the callers and leads to a more efficient implementation since the XArray has this functionality already. Link: https://lkml.kernel.org/r/20201112212641.27837-11-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: add and use find_lock_entriesMatthew Wilcox (Oracle)2021-02-261-0/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | We have three functions (shmem_undo_range(), truncate_inode_pages_range() and invalidate_mapping_pages()) which want exactly this function, so add it to filemap.c. Before this patch, shmem_undo_range() would split any compound page which overlaps either end of the range being punched in both the first and second loops through the address space. After this patch, that functionality is left for the second loop, which is arguably more appropriate since the first loop is supposed to run through all the pages quickly, and splitting a page can sleep. [willy@infradead.org: add assertion] Link: https://lkml.kernel.org/r/20201124041507.28996-3-willy@infradead.org Link: https://lkml.kernel.org/r/20201112212641.27837-10-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* iomap: use mapping_seek_hole_dataMatthew Wilcox (Oracle)2021-02-261-5/+32
| | | | | | | | | | | | | | | | | | Enhance mapping_seek_hole_data() to handle partially uptodate pages and convert the iomap seek code to call it. Link: https://lkml.kernel.org/r/20201112212641.27837-9-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: add mapping_seek_hole_dataMatthew Wilcox (Oracle)2021-02-261-0/+76
| | | | | | | | | | | | | | | | | | | | Rewrite shmem_seek_hole_data() and move it to filemap.c. [willy@infradead.org: don't put an xa_is_value() page] Link: https://lkml.kernel.org/r/20201124041507.28996-4-willy@infradead.org Link: https://lkml.kernel.org/r/20201112212641.27837-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: add helper for finding pagesMatthew Wilcox (Oracle)2021-02-261-55/+42
| | | | | | | | | | | | | | | | | | | | | There is a lot of common code in find_get_entries(), find_get_pages_range() and find_get_pages_range_tag(). Factor out find_get_entry() which simplifies all three functions. [willy@infradead.org: remove VM_BUG_ON_PAGE()] Link: https://lkml.kernel.org/r/20201124041507.28996-2-willy@infradead.orgLink: https://lkml.kernel.org/r/20201112212641.27837-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: rename find_get_entry to mapping_get_entryMatthew Wilcox (Oracle)2021-02-261-3/+4
| | | | | | | | | | | | | | | | | | find_get_entry doesn't "find" anything. It returns the entry at a particular index. Link: https://lkml.kernel.org/r/20201112212641.27837-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: add FGP_ENTRYMatthew Wilcox (Oracle)2021-02-261-36/+8
| | | | | | | | | | | | | | | | | | | The functionality of find_lock_entry() and find_get_entry() can be provided by pagecache_get_page(), which lets us delete find_lock_entry() and make find_get_entry() static. Link: https://lkml.kernel.org/r/20201112212641.27837-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: make pagecache tagged lookups return only head pagesMatthew Wilcox (Oracle)2021-02-261-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Overhaul multi-page lookups for THP", v4. This THP prep patchset changes several page cache iteration APIs to only return head pages. - It's only possible to tag head pages in the page cache, so only return head pages, not all their subpages. - Factor a lot of common code out of the various batch lookup routines - Add mapping_seek_hole_data() - Unify find_get_entries() and pagevec_lookup_entries() - Make find_get_entries only return head pages, like find_get_entry(). These are only loosely connected, but they seem to make sense together as a series. This patch (of 14): Pagecache tags are used for dirty page writeback. Since dirtiness is tracked on a per-THP basis, we only want to return the head page rather than each subpage of a tagged page. All the filesystems which use huge pages today are in-memory, so there are no tagged huge pages today. Link: https://lkml.kernel.org/r/20201112212641.27837-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Dave Chinner <dchinner@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memcontrol: convert NR_SHMEM_THPS account to pagesMuchun Song2021-02-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we use struct per_cpu_nodestat to cache the vmstat counters, which leads to inaccurate statistics especially THP vmstat counters. In the systems with hundreds of processors it can be GBs of memory. For example, for a 96 CPUs system, the threshold is the maximum number of 125. And the per cpu counters can cache 23.4375 GB in total. The THP page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like sensible. Although every THP stats update overflows the per-cpu counter, resorting to atomic global updates. But it can make the statistics more accuracy for the THP vmstat counters. So we convert the NR_SHMEM_THPS account to pages. This patch is consistent with 8f182270dfec ("mm/swap.c: flush lru pvecs on compound page arrival"). Doing this also can make the unit of vmstat counters more unified. Finally, the unit of the vmstat counters are pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes or kB. The rest which is without suffix are pages. Link: https://lkml.kernel.org/r/20201228164110.2838-5-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: NeilBrown <neilb@suse.de> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Rafael. J. Wysocki <rafael@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <guro@fb.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memcontrol: convert NR_FILE_THPS account to pagesMuchun Song2021-02-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we use struct per_cpu_nodestat to cache the vmstat counters, which leads to inaccurate statistics especially THP vmstat counters. In the systems with if hundreds of processors it can be GBs of memory. For example, for a 96 CPUs system, the threshold is the maximum number of 125. And the per cpu counters can cache 23.4375 GB in total. The THP page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like sensible. Although every THP stats update overflows the per-cpu counter, resorting to atomic global updates. But it can make the statistics more accuracy for the THP vmstat counters. So we convert the NR_FILE_THPS account to pages. This patch is consistent with 8f182270dfec ("mm/swap.c: flush lru pvecs on compound page arrival"). Doing this also can make the unit of vmstat counters more unified. Finally, the unit of the vmstat counters are pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes or kB. The rest which is without suffix are pages. Link: https://lkml.kernel.org/r/20201228164110.2838-4-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: NeilBrown <neilb@suse.de> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Rafael. J. Wysocki <rafael@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <guro@fb.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: simplify generic_file_read_iterChristoph Hellwig2021-02-241-6/+4
| | | | | | | | | | | | Avoid the pointless goto out just for returning retval. Link: https://lkml.kernel.org/r/20210122160140.223228-19-willy@infradead.org Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: rename generic_file_buffered_read to filemap_readChristoph Hellwig2021-02-241-19/+16
| | | | | | | | | | | | | | Rename generic_file_buffered_read to match the naming of filemap_fault, also update the written parameter to a more descriptive name and improve the kerneldoc comment. Link: https://lkml.kernel.org/r/20210122160140.223228-18-willy@infradead.org Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: don't relock the page after calling readpageMatthew Wilcox (Oracle)2021-02-241-14/+7
| | | | | | | | | | | | | | We don't need to get the page lock again; we just need to wait for the I/O to finish, so use wait_on_page_locked_killable() like the other callers of ->readpage. Link: https://lkml.kernel.org/r/20210122160140.223228-17-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: restructure filemap_get_pagesMatthew Wilcox (Oracle)2021-02-241-43/+28
| | | | | | | | | | | | | Remove the got_pages label, remove indentation, rename find_page to retry, simplify error handling. Link: https://lkml.kernel.org/r/20210122160140.223228-16-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: split filemap_readahead out of filemap_get_pagesMatthew Wilcox (Oracle)2021-02-241-5/+14
| | | | | | | | | | | | This simplifies the error handling. Link: https://lkml.kernel.org/r/20210122160140.223228-15-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: add filemap_range_uptodateMatthew Wilcox (Oracle)2021-02-241-26/+39
| | | | | | | | | | | | | | | | Move the complicated condition and the calculations out of filemap_update_page() into its own function. [willy@infradead.org: unlock page before dropping its refcount] Link: https://lkml.kernel.org/r/20210201125229.GO308988@casper.infradead.org Link: https://lkml.kernel.org/r/20210122160140.223228-14-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: move the iocb checks into filemap_update_pageMatthew Wilcox (Oracle)2021-02-241-14/+10
| | | | | | | | | | | | | We don't need to give up when a non-blocking request sees a !Uptodate page. We may be able to satisfy the read from a partially-uptodate page. Link: https://lkml.kernel.org/r/20210122160140.223228-13-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: convert filemap_update_page to return an errnoMatthew Wilcox (Oracle)2021-02-241-21/+17
| | | | | | | | | | | | | | | Use AOP_TRUNCATED_PAGE to indicate that no error occurred, but the page we looked up is no longer valid. In this case, the reference to the page will have been removed; if we hit any other error, the caller will release the reference. Link: https://lkml.kernel.org/r/20210122160140.223228-12-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: change filemap_create_page calling conventionsMatthew Wilcox (Oracle)2021-02-241-26/+27
| | | | | | | | | | | | | | | By moving the iocb flag checks to the caller, we can pass the file and the page index instead of the iocb. It never needed the iter. By passing the pagevec, we can return an errno (or AOP_TRUNCATED_PAGE) instead of an ERR_PTR. Link: https://lkml.kernel.org/r/20210122160140.223228-11-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: change filemap_read_page calling conventionsMatthew Wilcox (Oracle)2021-02-241-47/+42
| | | | | | | | | | | | | | | Make this function more generic by passing the file instead of the iocb. Check in the callers whether we should call readpage or not. Also make it return an errno / 0 / AOP_TRUNCATED_PAGE, and make calling put_page() the caller's responsibility. Link: https://lkml.kernel.org/r/20210122160140.223228-10-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: don't call ->readpage if IOCB_WAITQ is setMatthew Wilcox (Oracle)2021-02-241-12/+2
| | | | | | | | | | | | | | The readpage operation can block in many (most?) filesystems, so we should punt to a work queue instead of calling it. This was the last caller of lock_page_for_iocb(), so remove it. Link: https://lkml.kernel.org/r/20210122160140.223228-9-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: inline __wait_on_page_locked_async into callerMatthew Wilcox (Oracle)2021-02-241-31/+22
| | | | | | | | | | | | | The previous patch removed wait_on_page_locked_async(), so inline __wait_on_page_locked_async into __lock_page_async(). Link: https://lkml.kernel.org/r/20210122160140.223228-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: support readpage splitting a pageMatthew Wilcox (Oracle)2021-02-241-53/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | For page splitting to succeed, the thread asking to split the page has to be the only one with a reference to the page. Calling wait_on_page_locked() while holding a reference to the page will effectively prevent this from happening with sufficient threads waiting on the same page. Use put_and_wait_on_page_locked() to sleep without holding a reference to the page, then retry the page lookup after the page is unlocked. Since we now get the page lock a little earlier in filemap_update_page(), we can eliminate a number of duplicate checks. The original intent (commit ebded02788b5 ("avoid unnecessary calls to lock_page when waiting for IO to complete during a read")) behind getting the page lock later was to avoid re-locking the page after it has been brought uptodate by another thread. We still avoid that because we go through the normal lookup path again after the winning thread has brought the page uptodate. Link: https://lkml.kernel.org/r/20210122160140.223228-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: pass a sleep state to put_and_wait_on_page_lockedMatthew Wilcox (Oracle)2021-02-241-2/+5
| | | | | | | | | | | | | This is prep work for the next patch, but I think at least one of the current callers would prefer a killable sleep to an uninterruptible one. Link: https://lkml.kernel.org/r/20210122160140.223228-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: use head pages in generic_file_buffered_readMatthew Wilcox (Oracle)2021-02-241-37/+85
| | | | | | | | | | | | | | | | Add filemap_get_read_batch() which returns the head pages which represent a contiguous array of bytes in the file. It also stops when encountering a page marked as Readahead or !Uptodate (but does return that page) so it can be handled appropriately by filemap_get_pages(). That lets us remove the loop in filemap_get_pages() and check only the last page. Link: https://lkml.kernel.org/r/20210122160140.223228-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: convert filemap_get_pages to take a pagevecMatthew Wilcox (Oracle)2021-02-241-44/+38
| | | | | | | | | | | | | Using a pagevec lets us keep the pages and the number of pages together which simplifies a lot of the calling conventions. Link: https://lkml.kernel.org/r/20210122160140.223228-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: remove dynamically allocated array from filemap_readMatthew Wilcox (Oracle)2021-02-241-13/+2
| | | | | | | | | | | | | | Increasing the batch size runs into diminishing returns. It's probably better to make, eg, three calls to filemap_get_pages() than it is to call into kmalloc(). Link: https://lkml.kernel.org/r/20210122160140.223228-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: rename generic_file_buffered_read subfunctionsMatthew Wilcox (Oracle)2021-02-241-29/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Refactor generic_file_buffered_read", v5. This is a combination of Christoph's work to refactor generic_file_buffered_read() and some of my large-page support which was disrupted by Kent's refactoring of generic_file_buffered_read. This patch (of 18): The recent split of generic_file_buffered_read() created some very long function names which are hard to distinguish from each other. Rename as follows: generic_file_buffered_read_readpage -> filemap_read_page generic_file_buffered_read_pagenotuptodate -> filemap_update_page generic_file_buffered_read_no_cached_page -> filemap_create_page generic_file_buffered_read_get_pages -> filemap_get_pages Link: https://lkml.kernel.org/r/20210122160140.223228-1-willy@infradead.org Link: https://lkml.kernel.org/r/20210122160140.223228-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: don't revert iter on -EIOCBQUEUEDPavel Begunkov2021-02-241-2/+4
| | | | | | | | | | | | | | | Currently, if I/O is enqueued for async execution direct paths of generic_file_{read,write}_iter() will always revert the iter. There are no users expecting that, and that is also costly. Leave iterators as is on -EIOCBQUEUED. Link: https://lkml.kernel.org/r/f5247b60e7abbd2ff850cd108491f53a2e0c501a.1610207781.git.asml.silence@gmail.com Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/filemap: remove unused parameter and change to void type for ↵Baolin Wang2021-02-241-6/+1
| | | | | | | | | | | | | | | | replace_page_cache_page() Since commit 74d609585d8b ("page cache: Add and replace pages using the XArray") was merged, the replace_page_cache_page() can not fail and always return 0, we can remove the redundant return value and void it. Moreover remove the unused gfp_mask. Link: https://lkml.kernel.org/r/609c30e5274ba15d8b90c872fd0d8ac437a9b2bb.1610071401.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'arm64-upstream' of ↵Linus Torvalds2021-02-211-44/+135
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: - vDSO build improvements including support for building with BSD. - Cleanup to the AMU support code and initialisation rework to support cpufreq drivers built as modules. - Removal of synthetic frame record from exception stack when entering the kernel from EL0. - Add support for the TRNG firmware call introduced by Arm spec DEN0098. - Cleanup and refactoring across the board. - Avoid calling arch_get_random_seed_long() from add_interrupt_randomness() - Perf and PMU updates including support for Cortex-A78 and the v8.3 SPE extensions. - Significant steps along the road to leaving the MMU enabled during kexec relocation. - Faultaround changes to initialise prefaulted PTEs as 'old' when hardware access-flag updates are supported, which drastically improves vmscan performance. - CPU errata updates for Cortex-A76 (#1463225) and Cortex-A55 (#1024718) - Preparatory work for yielding the vector unit at a finer granularity in the crypto code, which in turn will one day allow us to defer softirq processing when it is in use. - Support for overriding CPU ID register fields on the command-line. * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (85 commits) drivers/perf: Replace spin_lock_irqsave to spin_lock mm: filemap: Fix microblaze build failure with 'mmu_defconfig' arm64: Make CPU_BIG_ENDIAN depend on ld.bfd or ld.lld 13.0.0+ arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line arm64: Defer enabling pointer authentication on boot core arm64: cpufeatures: Allow disabling of BTI from the command-line arm64: Move "nokaslr" over to the early cpufeature infrastructure KVM: arm64: Document HVC_VHE_RESTART stub hypercall arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0 arm64: Add an aliasing facility for the idreg override arm64: Honor VHE being disabled from the command-line arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line arm64: cpufeature: Add an early command-line cpufeature override facility arm64: Extract early FDT mapping from kaslr_early_init() arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding() arm64: cpufeature: Add global feature override facility arm64: Move SCTLR_EL1 initialisation to EL-agnostic code arm64: Simplify init_el2_state to be non-VHE only arm64: Move VHE-specific SPE setup to mutate_to_vhe() arm64: Drop early setting of MDSCR_EL2.TPMS ...
| * mm: filemap: Fix microblaze build failure with 'mmu_defconfig'Will Deacon2021-02-101-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit f9ce0be71d1f ("mm: Cleanup faultaround and finish_fault() codepaths") added a call to 'update_mmu_cache()' in mm/filemap.c, which breaks the build for microblaze: | mm/filemap.c: In function 'filemap_map_pages': | mm/filemap.c:3153:3: error: implicit declaration of function 'update_mmu_cache'; did you mean 'update_mmu_tlb'? Include asm/tlbflush.h in mm/filemap.c to make sure that the function (or indeed, macro) is available. Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20210209202449.GA104837@roeck-us.net Signed-off-by: Will Deacon <will@kernel.org>
| * mm: Pass 'address' to map to do_set_pte() and drop FAULT_FLAG_PREFAULTWill Deacon2021-01-211-14/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than modifying the 'address' field of the 'struct vm_fault' passed to do_set_pte(), leave that to identify the real faulting address and pass in the virtual address to be mapped by the new pte as a separate argument. This makes FAULT_FLAG_PREFAULT redundant, as a prefault entry can be identified simply by comparing the new address parameter with the faulting address, so remove the redundant flag at the same time. Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Will Deacon <will@kernel.org>
| * mm: Allow architectures to request 'old' entries when prefaultingWill Deacon2021-01-201-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 5c0a85fad949 ("mm: make faultaround produce old ptes") changed the "faultaround" behaviour to initialise prefaulted PTEs as 'old', since this avoids vmscan wrongly assuming that they are hot, despite having never been explicitly accessed by userspace. The change has been shown to benefit numerous arm64 micro-architectures (with hardware access flag) running Android, where both application launch latency and direct reclaim time are significantly reduced (by 10%+ and ~80% respectively). Unfortunately, commit 315d09bf30c2 ("Revert "mm: make faultaround produce old ptes"") reverted the change due to it being identified as the cause of a ~6% regression in unixbench on x86. Experiments on a variety of recent arm64 micro-architectures indicate that unixbench is not affected by the original commit, which appears to yield a 0-1% performance improvement. Since one size does not fit all for the initial state of prefaulted PTEs, introduce arch_wants_old_prefaulted_pte(), which allows an architecture to opt-in to 'old' prefaulted PTEs at runtime based on whatever criteria it may have. Cc: Jan Kara <jack@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Will Deacon <will@kernel.org>
| * mm: Cleanup faultaround and finish_fault() codepathsKirill A. Shutemov2021-01-201-43/+134
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | alloc_set_pte() has two users with different requirements: in the faultaround code, it called from an atomic context and PTE page table has to be preallocated. finish_fault() can sleep and allocate page table as needed. PTL locking rules are also strange, hard to follow and overkill for finish_fault(). Let's untangle the mess. alloc_set_pte() has gone now. All locking is explicit. The price is some code duplication to handle huge pages in faultaround path, but it should be fine, having overall improvement in readability. Link: https://lore.kernel.org/r/20201229132819.najtavneutnf7ajp@box Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> [will: s/from from/from/ in comment; spotted by willy] Signed-off-by: Will Deacon <will@kernel.org>