21 Oct, 2018

1 commit


01 Feb, 2018

1 commit

  • We don't have to use an entire 'long' for the number of elements in the
    pagevec; we know it's a number between 0 and 14 (now 15). So we can
    store it in a char, and then the bool packs next to it and we still have
    two or six bytes of padding for more elements in the header. That gives
    us space to cram in an extra page.

    Link: http://lkml.kernel.org/r/20171206022521.GM26021@bombadil.infradead.org
    Signed-off-by: Matthew Wilcox
    Acked-by: Michal Hocko
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Matthew Wilcox
     

16 Nov, 2017

6 commits

  • According to Vlastimil Babka, the drained field in pagevec is
    potentially misleading because it might be interpreted as draining this
    pagevec instead of the percpu lru pagevecs. Rename the field for
    clarity.

    Link: http://lkml.kernel.org/r/20171019093346.ylahzdpzmoriyf4v@techsingularity.net
    Signed-off-by: Mel Gorman
    Suggested-by: Vlastimil Babka
    Cc: Andi Kleen
    Cc: Dave Chinner
    Cc: Dave Hansen
    Cc: Jan Kara
    Cc: Johannes Weiner
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mel Gorman
     
  • Every pagevec_init user claims the pages being released are hot even in
    cases where it is unlikely the pages are hot. As no one cares about the
    hotness of pages being released to the allocator, just ditch the
    parameter.

    No performance impact is expected as the overhead is marginal. The
    parameter is removed simply because it is a bit stupid to have a useless
    parameter copied everywhere.

    Link: http://lkml.kernel.org/r/20171018075952.10627-6-mgorman@techsingularity.net
    Signed-off-by: Mel Gorman
    Acked-by: Vlastimil Babka
    Cc: Andi Kleen
    Cc: Dave Chinner
    Cc: Dave Hansen
    Cc: Jan Kara
    Cc: Johannes Weiner
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mel Gorman
     
  • When a pagevec is initialised on the stack, it is generally used
    multiple times over a range of pages, looking up entries and then
    releasing them. On each pagevec_release, the per-cpu deferred LRU
    pagevecs are drained on the grounds the page being released may be on
    those queues and the pages may be cache hot. In many cases only the
    first drain is necessary as it's unlikely that the range of pages being
    walked is racing against LRU addition. Even if there is such a race,
    the impact is marginal where as constantly redraining the lru pagevecs
    costs.

    This patch ensures that pagevec is only drained once in a given
    lifecycle without increasing the cache footprint of the pagevec
    structure. Only sparsetruncate tiny is shown here as large files have
    many exceptional entries and calls pagecache_release less frequently.

    sparsetruncate (tiny)
    4.14.0-rc4 4.14.0-rc4
    batchshadow-v1r1 onedrain-v1r1
    Min Time 141.00 ( 0.00%) 141.00 ( 0.00%)
    1st-qrtle Time 142.00 ( 0.00%) 142.00 ( 0.00%)
    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 146.00 ( 0.00%) 145.00 ( 0.68%)
    Max-99% Time 198.00 ( 0.00%) 194.00 ( 2.02%)
    Max Time 254.00 ( 0.00%) 208.00 ( 18.11%)
    Amean Time 145.12 ( 0.00%) 144.30 ( 0.56%)
    Stddev Time 12.74 ( 0.00%) 9.62 ( 24.49%)
    Coeff Time 8.78 ( 0.00%) 6.67 ( 24.06%)
    Best99%Amean Time 144.29 ( 0.00%) 143.82 ( 0.32%)
    Best95%Amean Time 142.68 ( 0.00%) 142.31 ( 0.26%)
    Best90%Amean Time 142.52 ( 0.00%) 142.19 ( 0.24%)
    Best75%Amean Time 142.26 ( 0.00%) 141.98 ( 0.20%)
    Best50%Amean Time 141.90 ( 0.00%) 141.71 ( 0.13%)
    Best25%Amean Time 141.80 ( 0.00%) 141.43 ( 0.26%)

    The impact on bonnie is marginal and within the noise because a
    significant percentage of the file being truncated has been reclaimed
    and consists of shadow entries which reduce the hotness of the
    pagevec_release path.

    Link: http://lkml.kernel.org/r/20171018075952.10627-5-mgorman@techsingularity.net
    Signed-off-by: Mel Gorman
    Cc: Andi Kleen
    Cc: Dave Chinner
    Cc: Dave Hansen
    Cc: Jan Kara
    Cc: Johannes Weiner
    Cc: Vlastimil Babka
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mel Gorman
     
  • All users of pagevec_lookup() and pagevec_lookup_range() now pass
    PAGEVEC_SIZE as a desired number of pages. Just drop the argument.

    Link: http://lkml.kernel.org/r/20171009151359.31984-15-jack@suse.cz
    Signed-off-by: Jan Kara
    Reviewed-by: Daniel Jordan
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jan Kara
     
  • Currently pagevec_lookup_range_tag() takes number of pages to look up
    but most users don't need this. Create a new function
    pagevec_lookup_range_nr_tag() that takes maximum number of pages to
    lookup for Ceph which wants this functionality so that we can drop
    nr_pages argument from pagevec_lookup_range_tag().

    Link: http://lkml.kernel.org/r/20171009151359.31984-13-jack@suse.cz
    Signed-off-by: Jan Kara
    Reviewed-by: Daniel Jordan
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jan Kara
     
  • Patch series "Ranged pagevec tagged lookup", v3.

    In this series I provide a ranged variant of pagevec_lookup_tag() and
    use it in places where it makes sense. This series removes some common
    code and it also has a potential for speeding up some operations
    similarly as for pagevec_lookup_range() (but for now I can think of only
    artificial cases where this happens).

    This patch (of 16):

    Implement a variant of find_get_pages_tag() that stops iterating at
    given index. Lots of users of this function (through pagevec_lookup())
    actually want a range lookup and all of them are currently open-coding
    this.

    Also create corresponding pagevec_lookup_range_tag() function.

    Link: http://lkml.kernel.org/r/20171009151359.31984-2-jack@suse.cz
    Signed-off-by: Jan Kara
    Reviewed-by: Daniel Jordan
    Cc: Bob Peterson
    Cc: Chao Yu
    Cc: David Howells
    Cc: David Sterba
    Cc: Ilya Dryomov
    Cc: Jaegeuk Kim
    Cc: Ryusuke Konishi
    Cc: Steve French
    Cc: "Theodore Ts'o"
    Cc: "Yan, Zheng"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jan Kara
     

02 Nov, 2017

1 commit

  • 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
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

07 Sep, 2017

3 commits

  • All users of pagevec_lookup() and pagevec_lookup_range() now pass
    PAGEVEC_SIZE as a desired number of pages.

    Just drop the argument.

    Link: http://lkml.kernel.org/r/20170726114704.7626-11-jack@suse.cz
    Signed-off-by: Jan Kara
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jan Kara
     
  • Implement a variant of find_get_pages() that stops iterating at given
    index. This may be substantial performance gain if the mapping is
    sparse. See following commit for details. Furthermore lots of users of
    this function (through pagevec_lookup()) actually want a range lookup
    and all of them are currently open-coding this.

    Also create corresponding pagevec_lookup_range() function.

    Link: http://lkml.kernel.org/r/20170726114704.7626-4-jack@suse.cz
    Signed-off-by: Jan Kara
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jan Kara
     
  • Make pagevec_lookup() (and underlying find_get_pages()) update index to
    the next page where iteration should continue. Most callers want this
    and also pagevec_lookup_tag() already does this.

    Link: http://lkml.kernel.org/r/20170726114704.7626-3-jack@suse.cz
    Signed-off-by: Jan Kara
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jan Kara
     

04 Apr, 2014

1 commit

  • shmem mappings already contain exceptional entries where swap slot
    information is remembered.

    To be able to store eviction information for regular page cache, prepare
    every site dealing with the radix trees directly to handle entries other
    than pages.

    The common lookup functions will filter out non-page entries and return
    NULL for page cache holes, just as before. But provide a raw version of
    the API which returns non-page entries as well, and switch shmem over to
    use it.

    Signed-off-by: Johannes Weiner
    Reviewed-by: Rik van Riel
    Reviewed-by: Minchan Kim
    Cc: Andrea Arcangeli
    Cc: Bob Liu
    Cc: Christoph Hellwig
    Cc: Dave Chinner
    Cc: Greg Thelen
    Cc: Hugh Dickins
    Cc: Jan Kara
    Cc: KOSAKI Motohiro
    Cc: Luigi Semenzato
    Cc: Mel Gorman
    Cc: Metin Doslu
    Cc: Michel Lespinasse
    Cc: Ozgun Erdogan
    Cc: Peter Zijlstra
    Cc: Roman Gushchin
    Cc: Ryan Mallon
    Cc: Tejun Heo
    Cc: Vlastimil Babka
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Johannes Weiner
     

04 Jul, 2013

1 commit

  • Now that the LRU to add a page to is decided at LRU-add time, remove the
    misleading lru parameter from __pagevec_lru_add. A consequence of this
    is that the pagevec_lru_add_file, pagevec_lru_add_anon and similar
    helpers are misleading as the caller no longer has direct control over
    what LRU the page is added to. Unused helpers are removed by this patch
    and existing users of pagevec_lru_add_file() are converted to use
    lru_cache_add_file() directly and use the per-cpu pagevecs instead of
    creating their own pagevec.

    Signed-off-by: Mel Gorman
    Reviewed-by: Jan Kara
    Reviewed-by: Rik van Riel
    Acked-by: Johannes Weiner
    Cc: Alexey Lyahkov
    Cc: Andrew Perepechko
    Cc: Robin Dong
    Cc: Theodore Tso
    Cc: Hugh Dickins
    Cc: Rik van Riel
    Cc: Bernd Schubert
    Cc: David Howells
    Cc: Trond Myklebust
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Mel Gorman
     

13 Jan, 2012

2 commits

  • What's so special about ____pagevec_lru_add() that it needs four leading
    underscores? Nothing, it just helped to distinguish from
    __pagevec_lru_add() in 2.6.28 development. Cut two leading underscores.

    Signed-off-by: Hugh Dickins
    Reviewed-by: KOSAKI Motohiro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     
  • Replace pagevecs in putback_lru_pages() and move_active_pages_to_lru()
    by lists of pages_to_free: then apply Konstantin Khlebnikov's
    free_hot_cold_page_list() to them instead of pagevec_release().

    Which simplifies the flow (no need to drop and retake lock whenever
    pagevec fills up) and reduces stale addresses in stack backtraces
    (which often showed through the pagevecs); but more importantly,
    removes another 120 bytes from the deepest stacks in page reclaim.
    Although I've not recently seen an actual stack overflow here with
    a vanilla kernel, move_active_pages_to_lru() has often featured in
    deep backtraces.

    However, free_hot_cold_page_list() does not handle compound pages
    (nor need it: a Transparent HugePage would have been split by the
    time it reaches the call in shrink_page_list()), but it is possible
    for putback_lru_pages() or move_active_pages_to_lru() to be left
    holding the last reference on a THP, so must exclude the unlikely
    compound case before putting on pages_to_free.

    Remove pagevec_strip(), its work now done in move_active_pages_to_lru().
    The pagevec in scan_mapping_unevictable_pages() remains in mm/vmscan.c,
    but that is never on the reclaim path, and cannot be replaced by a list.

    Signed-off-by: Hugh Dickins
    Reviewed-by: KOSAKI Motohiro
    Reviewed-by: Konstantin Khlebnikov
    Cc: KAMEZAWA Hiroyuki
    Cc: Mel Gorman
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     

11 Jan, 2012

1 commit


01 Apr, 2009

1 commit


07 Jan, 2009

1 commit

  • speculative page references patch (commit:
    e286781d5f2e9c846e012a39653a166e9d31777d) removed last
    pagevec_release_nonlru() caller.

    So this function can be removed now.

    This patch doesn't have any functional change.

    Signed-off-by: KOSAKI Motohiro
    Cc: Nick Piggin
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    KOSAKI Motohiro
     

20 Oct, 2008

4 commits

  • When the system contains lots of mlocked or otherwise unevictable pages,
    the pageout code (kswapd) can spend lots of time scanning over these
    pages. Worse still, the presence of lots of unevictable pages can confuse
    kswapd into thinking that more aggressive pageout modes are required,
    resulting in all kinds of bad behaviour.

    Infrastructure to manage pages excluded from reclaim--i.e., hidden from
    vmscan. Based on a patch by Larry Woodman of Red Hat. Reworked to
    maintain "unevictable" pages on a separate per-zone LRU list, to "hide"
    them from vmscan.

    Kosaki Motohiro added the support for the memory controller unevictable
    lru list.

    Pages on the unevictable list have both PG_unevictable and PG_lru set.
    Thus, PG_unevictable is analogous to and mutually exclusive with
    PG_active--it specifies which LRU list the page is on.

    The unevictable infrastructure is enabled by a new mm Kconfig option
    [CONFIG_]UNEVICTABLE_LRU.

    A new function 'page_evictable(page, vma)' in vmscan.c tests whether or
    not a page may be evictable. Subsequent patches will add the various
    !evictable tests. We'll want to keep these tests light-weight for use in
    shrink_active_list() and, possibly, the fault path.

    To avoid races between tasks putting pages [back] onto an LRU list and
    tasks that might be moving the page from non-evictable to evictable state,
    the new function 'putback_lru_page()' -- inverse to 'isolate_lru_page()'
    -- tests the "evictability" of a page after placing it on the LRU, before
    dropping the reference. If the page has become unevictable,
    putback_lru_page() will redo the 'putback', thus moving the page to the
    unevictable list. This way, we avoid "stranding" evictable pages on the
    unevictable list.

    [akpm@linux-foundation.org: fix fallout from out-of-order merge]
    [riel@redhat.com: fix UNEVICTABLE_LRU and !PROC_PAGE_MONITOR build]
    [nishimura@mxp.nes.nec.co.jp: remove redundant mapping check]
    [kosaki.motohiro@jp.fujitsu.com: unevictable-lru-infrastructure: putback_lru_page()/unevictable page handling rework]
    [kosaki.motohiro@jp.fujitsu.com: kill unnecessary lock_page() in vmscan.c]
    [kosaki.motohiro@jp.fujitsu.com: revert migration change of unevictable lru infrastructure]
    [kosaki.motohiro@jp.fujitsu.com: revert to unevictable-lru-infrastructure-kconfig-fix.patch]
    [kosaki.motohiro@jp.fujitsu.com: restore patch failure of vmstat-unevictable-and-mlocked-pages-vm-events.patch]
    Signed-off-by: Lee Schermerhorn
    Signed-off-by: Rik van Riel
    Signed-off-by: KOSAKI Motohiro
    Debugged-by: Benjamin Kidwell
    Signed-off-by: Daisuke Nishimura
    Signed-off-by: KAMEZAWA Hiroyuki
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Lee Schermerhorn
     
  • Split the LRU lists in two, one set for pages that are backed by real file
    systems ("file") and one for pages that are backed by memory and swap
    ("anon"). The latter includes tmpfs.

    The advantage of doing this is that the VM will not have to scan over lots
    of anonymous pages (which we generally do not want to swap out), just to
    find the page cache pages that it should evict.

    This patch has the infrastructure and a basic policy to balance how much
    we scan the anon lists and how much we scan the file lists. The big
    policy changes are in separate patches.

    [lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset]
    [kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru]
    [kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page]
    [hugh@veritas.com: memcg swapbacked pages active]
    [hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED]
    [akpm@linux-foundation.org: fix /proc/vmstat units]
    [nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration]
    [kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo]
    [kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()]
    Signed-off-by: Rik van Riel
    Signed-off-by: Lee Schermerhorn
    Signed-off-by: KOSAKI Motohiro
    Signed-off-by: Hugh Dickins
    Signed-off-by: Daisuke Nishimura
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Rik van Riel
     
  • If vm_swap_full() (swap space more than 50% full), the system will free
    swap space at swapin time. With this patch, the system will also free the
    swap space in the pageout code, when we decide that the page is not a
    candidate for swapout (and just wasting swap space).

    Signed-off-by: Rik van Riel
    Signed-off-by: Lee Schermerhorn
    Signed-off-by: MinChan Kim
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Rik van Riel
     
  • Turn the pagevecs into an array just like the LRUs. This significantly
    cleans up the source code and reduces the size of the kernel by about 13kB
    after all the LRU lists have been created further down in the split VM
    patch series.

    Signed-off-by: Rik van Riel
    Signed-off-by: KOSAKI Motohiro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    KOSAKI Motohiro
     

09 Jan, 2006

1 commit


17 Apr, 2005

1 commit

  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds