kernel.git/mm/workingset.c, branch linux-4.18.y

page cache: use xa_lock

2018-04-11T17:28:39Z

Remove the address_space ->tree_lock and use the xa_lock newly added to the radix_tree_root. Rename the address_space ->page_tree to ->i_pages, since we don't really care that it's a tree. [willy@infradead.org: fix nds32, fs/dax.c] Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.org Signed-off-by: Matthew Wilcox Acked-by: Jeff Layton Cc: Darrick J. Wong Cc: Dave Chinner Cc: Ryusuke Konishi Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, truncate: do not check mapping for every page being truncated

2017-11-16T02:21:06Z

During truncation, the mapping has already been checked for shmem and dax so it's known that workingset_update_node is required. This patch avoids the checks on mapping for each page being truncated. In all other cases, a lookup helper is used to determine if workingset_update_node() needs to be called. The one danger is that the API is slightly harder to use as calling workingset_update_node directly without checking for dax or shmem mappings could lead to surprises. However, the API rarely needs to be used and hopefully the comment is enough to give people the hint. sparsetruncate (tiny) 4.14.0-rc4 4.14.0-rc4 oneirq-v1r1 pickhelper-v1r1 Min Time 141.00 ( 0.00%) 140.00 ( 0.71%) 1st-qrtle Time 142.00 ( 0.00%) 141.00 ( 0.70%) 2nd-qrtle Time 142.00 ( 0.00%) 142.00 ( 0.00%) 3rd-qrtle Time 143.00 ( 0.00%) 143.00 ( 0.00%) Max-90% Time 144.00 ( 0.00%) 144.00 ( 0.00%) Max-95% Time 147.00 ( 0.00%) 145.00 ( 1.36%) Max-99% Time 195.00 ( 0.00%) 191.00 ( 2.05%) Max Time 230.00 ( 0.00%) 205.00 ( 10.87%) Amean Time 144.37 ( 0.00%) 143.82 ( 0.38%) Stddev Time 10.44 ( 0.00%) 9.00 ( 13.74%) Coeff Time 7.23 ( 0.00%) 6.26 ( 13.41%) Best99%Amean Time 143.72 ( 0.00%) 143.34 ( 0.26%) Best95%Amean Time 142.37 ( 0.00%) 142.00 ( 0.26%) Best90%Amean Time 142.19 ( 0.00%) 141.85 ( 0.24%) Best75%Amean Time 141.92 ( 0.00%) 141.58 ( 0.24%) Best50%Amean Time 141.69 ( 0.00%) 141.31 ( 0.27%) Best25%Amean Time 141.38 ( 0.00%) 140.97 ( 0.29%) As you'd expect, the gain is marginal but it can be detected. The differences in bonnie are all within the noise which is not surprising given the impact on the microbenchmark. radix_tree_update_node_t is a callback for some radix operations that optionally passes in a private field. The only user of the callback is workingset_update_node and as it no longer requires a mapping, the private field is removed. Link: http://lkml.kernel.org/r/20171018075952.10627-3-mgorman@techsingularity.net Signed-off-by: Mel Gorman Acked-by: Johannes Weiner Reviewed-by: Jan Kara Cc: Andi Kleen Cc: Dave Chinner Cc: Dave Hansen Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

mm: memcontrol: per-lruvec stats infrastructure

2017-07-06T23:24:35Z

lruvecs are at the intersection of the NUMA node and memcg, which is the scope for most paging activity. Introduce a convenient accounting infrastructure that maintains statistics per node, per memcg, and the lruvec itself. Then convert over accounting sites for statistics that are already tracked in both nodes and memcgs and can be easily switched. [hannes@cmpxchg.org: fix crash in the new cgroup stat keeping code] Link: http://lkml.kernel.org/r/20170531171450.GA10481@cmpxchg.org [hannes@cmpxchg.org: don't track uncharged pages at all Link: http://lkml.kernel.org/r/20170605175254.GA8547@cmpxchg.org [hannes@cmpxchg.org: add missing free_percpu()] Link: http://lkml.kernel.org/r/20170605175354.GB8547@cmpxchg.org [linux@roeck-us.net: hexagon: fix build error caused by include file order] Link: http://lkml.kernel.org/r/20170617153721.GA4382@roeck-us.net Link: http://lkml.kernel.org/r/20170530181724.27197-6-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Signed-off-by: Guenter Roeck Acked-by: Vladimir Davydov Cc: Josef Bacik Cc: Michal Hocko Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: memcontrol: use node page state naming scheme for memcg

2017-05-03T22:52:11Z

The memory controllers stat function names are awkwardly long and arbitrarily different from the zone and node stat functions. The current interface is named: mem_cgroup_read_stat() mem_cgroup_update_stat() mem_cgroup_inc_stat() mem_cgroup_dec_stat() mem_cgroup_update_page_stat() mem_cgroup_inc_page_stat() mem_cgroup_dec_page_stat() This patch renames it to match the corresponding node stat functions: memcg_page_state() [node_page_state()] mod_memcg_state() [mod_node_state()] inc_memcg_state() [inc_node_state()] dec_memcg_state() [dec_node_state()] mod_memcg_page_state() [mod_node_page_state()] inc_memcg_page_state() [inc_node_page_state()] dec_memcg_page_state() [dec_node_page_state()] Link: http://lkml.kernel.org/r/20170404220148.28338-4-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Acked-by: Vladimir Davydov Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: memcontrol: re-use node VM page state enum

2017-05-03T22:52:11Z

The current duplication is a high-maintenance mess, and it's painful to add new items or query memcg state from the rest of the VM. This increases the size of the stat array marginally, but we should aim to track all these stats on a per-cgroup level anyway. Link: http://lkml.kernel.org/r/20170404220148.28338-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Acked-by: Vladimir Davydov Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: vmscan: fix IO/refault regression in cache workingset transition

2017-05-03T22:52:11Z

Since commit 59dc76b0d4df ("mm: vmscan: reduce size of inactive file list") we noticed bigger IO spikes during changes in cache access patterns. The patch in question shrunk the inactive list size to leave more room for the current workingset in the presence of streaming IO. However, workingset transitions that previously happened on the inactive list are now pushed out of memory and incur more refaults to complete. This patch disables active list protection when refaults are being observed. This accelerates workingset transitions, and allows more of the new set to establish itself from memory, without eating into the ability to protect the established workingset during stable periods. The workloads that were measurably affected for us were hit pretty bad by it, with refault/majfault rates doubling and tripling during cache transitions, and the machines sustaining half-hour periods of 100% IO utilization, where they'd previously have sub-minute peaks at 60-90%. Stateful services that handle user data tend to be more conservative with kernel upgrades. As a result we hit most page cache issues with some delay, as was the case here. The severity seemed to warrant a stable tag. Fixes: 59dc76b0d4df ("mm: vmscan: reduce size of inactive file list") Link: http://lkml.kernel.org/r/20170404220052.27593-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Cc: Rik van Riel Cc: Mel Gorman Cc: Michal Hocko Cc: Vladimir Davydov Cc: [4.7+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: workingset: fix premature shadow node shrinking with cgroups

2017-04-01T00:13:30Z

Commit 0a6b76dd23fa ("mm: workingset: make shadow node shrinker memcg aware") enabled cgroup-awareness in the shadow node shrinker, but forgot to also enable cgroup-awareness in the list_lru the shadow nodes sit on. Consequently, all shadow nodes are sitting on a global (per-NUMA node) list, while the shrinker applies the limits according to the amount of cache in the cgroup its shrinking. The result is excessive pressure on the shadow nodes from cgroups that have very little cache. Enable memcg-mode on the shadow node LRUs, such that per-cgroup limits are applied to per-cgroup lists. Fixes: 0a6b76dd23fa ("mm: workingset: make shadow node shrinker memcg aware") Link: http://lkml.kernel.org/r/20170322005320.8165-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Acked-by: Vladimir Davydov Cc: Michal Hocko Cc: [4.6+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'idr-4.11' of git://git.infradead.org/users/willy/linux-dax

2017-03-01T04:29:41Z

Pull IDR rewrite from Matthew Wilcox: "The most significant part of the following is the patch to rewrite the IDR & IDA to be clients of the radix tree. But there's much more, including an enhancement of the IDA to be significantly more space efficient, an IDR & IDA test suite, some improvements to the IDR API (and driver changes to take advantage of those improvements), several improvements to the radix tree test suite and RCU annotations. The IDR & IDA rewrite had a good spin in linux-next and Andrew's tree for most of the last cycle. Coupled with the IDR test suite, I feel pretty confident that any remaining bugs are quite hard to hit. 0-day did a great job of watching my git tree and pointing out problems; as it hit them, I added new test-cases to be sure not to be caught the same way twice" Willy goes on to expand a bit on the IDR rewrite rationale: "The radix tree and the IDR use very similar data structures. Merging the two codebases lets us share the memory allocation pools, and results in a net deletion of 500 lines of code. It also opens up the possibility of exposing more of the features of the radix tree to users of the IDR (and I have some interesting patches along those lines waiting for 4.12) It also shrinks the size of the 'struct idr' from 40 bytes to 24 which will shrink a fair few data structures that embed an IDR" * 'idr-4.11' of git://git.infradead.org/users/willy/linux-dax: (32 commits) radix tree test suite: Add config option for map shift idr: Add missing __rcu annotations radix-tree: Fix __rcu annotations radix-tree: Add rcu_dereference and rcu_assign_pointer calls radix tree test suite: Run iteration tests for longer radix tree test suite: Fix split/join memory leaks radix tree test suite: Fix leaks in regression2.c radix tree test suite: Fix leaky tests radix tree test suite: Enable address sanitizer radix_tree_iter_resume: Fix out of bounds error radix-tree: Store a pointer to the root in each node radix-tree: Chain preallocated nodes through ->parent radix tree test suite: Dial down verbosity with -v radix tree test suite: Introduce kmalloc_verbose idr: Return the deleted entry from idr_remove radix tree test suite: Build separate binaries for some tests ida: Use exceptional entries for small IDAs ida: Move ida_bitmap to a percpu variable Reimplement IDR and IDA using the radix tree radix-tree: Add radix_tree_iter_delete ...

mm: remove shmem_mapping() shmem_zero_setup() duplicates

2017-02-25T01:46:56Z

Remove the prototypes for shmem_mapping() and shmem_zero_setup() from linux/mm.h, since they are already provided in linux/shmem_fs.h. But shmem_fs.h must then provide the inline stub for shmem_mapping() when CONFIG_SHMEM is not set, and a few more cfiles now need to #include it. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1702081658250.1549@eggly.anvils Signed-off-by: Hugh Dickins Cc: Johannes Weiner Cc: Michal Simek Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds