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android / kernel / common / 3889296829f1a1fc18da8b3d99caaf834db2691b
commit3889296829f1a1fc18da8b3d99caaf834db2691b[log] [tgz]
authorLei Liu <liulei.rjpt@vivo.corp-partner.google.com>Wed Jul 03 15:03:58 2024 +0800
committerLei Liu <liulei.rjpt@vivo.corp-partner.google.com>Wed Jul 03 15:03:58 2024 +0800
treec7459fa2531098c6e09606db3f38c61511c1adcf
parent6d9feaf249b225744582e627c4b7aa9488b218d7 [diff]
FROMLIST: binder_alloc: Replace kcalloc with kvcalloc to mitigate OOM issues

In binder_alloc, there is a frequent need for order3 memory allocation,
especially on small-memory mobile devices, which can lead to OOM and
cause foreground applications to be killed, resulting in flashbacks.

We use kvcalloc to allocate memory, which can reduce system OOM
occurrences, as well as decrease the time and probability of failure for
order3 memory allocations. Additionally, It has little impact on the
throughput of the binder. (as verified by Google's binder_benchmark
testing tool).

We have conducted multiple tests on an 8GB memory phone, kvcalloc has
little performance degradation and resolves frequent OOM issues, Below
is a partial excerpt of the test data.

throughput(TH_PUT) = (size * Iterations)/Time
kcalloc->kvcalloc:

Sample with kcalloc():
adb shell stop/ kcalloc /8+256G
---------------------------------------------------------------------
Benchmark                Time     CPU   Iterations  TH-PUT  TH-PUTCPU
                         (ns)     (ns)              (GB/s)    (GB/s)
---------------------------------------------------------------------
BM_sendVec_binder4      39126    18550    38894    3.976282  8.38684
BM_sendVec_binder8      38924    18542    37786    7.766108  16.3028
BM_sendVec_binder16     38328    18228    36700    15.32039  32.2141
BM_sendVec_binder32     38154    18215    38240    32.07213  67.1798
BM_sendVec_binder64     39093    18809    36142    59.16885  122.977
BM_sendVec_binder128    40169    19188    36461    116.1843  243.2253
BM_sendVec_binder256    40695    19559    35951    226.1569  470.5484
BM_sendVec_binder512    41446    20211    34259    423.2159  867.8743
BM_sendVec_binder1024   44040    22939    28904    672.0639  1290.278
BM_sendVec_binder2048   47817    25821    26595    1139.063  2109.393
BM_sendVec_binder4096   54749    30905    22742    1701.423  3014.115
BM_sendVec_binder8192   68316    42017    16684    2000.634  3252.858
BM_sendVec_binder16384  95435    64081    10961    1881.752  2802.469
BM_sendVec_binder32768  148232  107504     6510    1439.093  1984.295
BM_sendVec_binder65536  326499  229874     3178    637.8991  906.0329
NORAML TEST                                 SUM    10355.79  17188.15
stressapptest eat 2G                        SUM    10088.39  16625.97

Sample with kvcalloc():
adb shell stop/ kvcalloc /8+256G
----------------------------------------------------------------------
Benchmark                Time     CPU   Iterations  TH-PUT  TH-PUTCPU
                         (ns)     (ns)              (GB/s)    (GB/s)
----------------------------------------------------------------------
BM_sendVec_binder4       39673    18832    36598    3.689965  7.773577
BM_sendVec_binder8       39869    18969    37188    7.462038  15.68369
BM_sendVec_binder16      39774    18896    36627    14.73405  31.01355
BM_sendVec_binder32      40225    19125    36995    29.43045  61.90013
BM_sendVec_binder64      40549    19529    35148    55.47544  115.1862
BM_sendVec_binder128     41580    19892    35384    108.9262  227.6871
BM_sendVec_binder256     41584    20059    34060    209.6806  434.6857
BM_sendVec_binder512     42829    20899    32493    388.4381  796.0389
BM_sendVec_binder1024    45037    23360    29251    665.0759  1282.236
BM_sendVec_binder2048    47853    25761    27091    1159.433  2153.735
BM_sendVec_binder4096    55574    31745    22405    1651.328  2890.877
BM_sendVec_binder8192    70706    43693    16400    1900.105  3074.836
BM_sendVec_binder16384   96161    64362    10793    1838.921  2747.468
BM_sendVec_binder32768  147875   107292     6296    1395.147  1922.858
BM_sendVec_binder65536  330324   232296     3053    605.7126  861.3209
NORAML TEST                                 SUM     10033.56  16623.35
stressapptest eat 2G                        SUM      9958.43  16497.55

Signed-off-by: Lei Liu <liulei.rjpt@vivo.com>
Acked-by: Carlos Llamas <cmllamas@google.com>

Bug: 350604214
Bug: 331900628
Link: https://lore.kernel.org/all/20240619113841.3362-1-liulei.rjpt@vivo.com/

Change-Id: I46e19121d03466e9f1ac42c8c7731c92b9eb9bbf
Signed-off-by: Lei Liu <liulei.rjpt@vivo.corp-partner.google.com>
1 file changed
tree: c7459fa2531098c6e09606db3f38c61511c1adcf
  1. android/
  2. arch/
  3. block/
  4. certs/
  5. crypto/
  6. Documentation/
  7. drivers/
  8. fs/
  9. include/
  10. init/
  11. io_uring/
  12. ipc/
  13. kernel/
  14. lib/
  15. LICENSES/
  16. mm/
  17. net/
  18. samples/
  19. scripts/
  20. security/
  21. sound/
  22. tools/
  23. usr/
  24. virt/
  25. .clang-format
  26. .cocciconfig
  27. .get_maintainer.ignore
  28. .gitattributes
  29. .gitignore
  30. .mailmap
  31. build.config.aarch64
  32. build.config.allmodconfig
  33. build.config.allmodconfig.aarch64
  34. build.config.allmodconfig.arm
  35. build.config.allmodconfig.x86_64
  36. build.config.amlogic
  37. build.config.arm
  38. build.config.common
  39. build.config.db845c
  40. build.config.gki
  41. build.config.gki-debug.aarch64
  42. build.config.gki-debug.x86_64
  43. build.config.gki.aarch64
  44. build.config.gki.aarch64.fips140
  45. build.config.gki.aarch64.fips140_eval_testing
  46. build.config.gki.x86_64
  47. build.config.gki_kasan
  48. build.config.gki_kasan.aarch64
  49. build.config.gki_kasan.x86_64
  50. build.config.gki_kprobes
  51. build.config.gki_kprobes.aarch64
  52. build.config.gki_kprobes.x86_64
  53. build.config.hikey960
  54. build.config.khwasan
  55. build.config.rockchip
  56. build.config.x86_64
  57. COPYING
  58. CREDITS
  59. Kbuild
  60. Kconfig
  61. MAINTAINERS
  62. Makefile
  63. OWNERS
  64. README
  65. README.md
README.md

How do I submit patches to Android Common Kernels

  1. BEST: Make all of your changes to upstream Linux. If appropriate, backport to the stable releases. These patches will be merged automatically in the corresponding common kernels. If the patch is already in upstream Linux, post a backport of the patch that conforms to the patch requirements below.

    • Do not send patches upstream that contain only symbol exports. To be considered for upstream Linux, additions of EXPORT_SYMBOL_GPL() require an in-tree modular driver that uses the symbol -- so include the new driver or changes to an existing driver in the same patchset as the export.
    • When sending patches upstream, the commit message must contain a clear case for why the patch is needed and beneficial to the community. Enabling out-of-tree drivers or functionality is not not a persuasive case.

  2. LESS GOOD: Develop your patches out-of-tree (from an upstream Linux point-of-view). Unless these are fixing an Android-specific bug, these are very unlikely to be accepted unless they have been coordinated with kernel-team@android.com. If you want to proceed, post a patch that conforms to the patch requirements below.

Common Kernel patch requirements

  • All patches must conform to the Linux kernel coding standards and pass script/checkpatch.pl
  • Patches shall not break gki_defconfig or allmodconfig builds for arm, arm64, x86, x86_64 architectures (see https://source.android.com/setup/build/building-kernels)
  • If the patch is not merged from an upstream branch, the subject must be tagged with the type of patch: UPSTREAM:, BACKPORT:, FROMGIT:, FROMLIST:, or ANDROID:.
  • All patches must have a Change-Id: tag (see https://gerrit-review.googlesource.com/Documentation/user-changeid.html)
  • If an Android bug has been assigned, there must be a Bug: tag.
  • All patches must have a Signed-off-by: tag by the author and the submitter

Additional requirements are listed below based on patch type

Requirements for backports from mainline Linux: UPSTREAM:, BACKPORT:

  • If the patch is a cherry-pick from Linux mainline with no changes at all
    • tag the patch subject with UPSTREAM:.
    • add upstream commit information with a (cherry picked from commit ...) line
    • Example:
      • if the upstream commit message is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>
  • then Joe Smith would upload the patch for the common kernel as
        UPSTREAM: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch requires any changes from the upstream version, tag the patch with BACKPORT: instead of UPSTREAM:.
    • use the same tags as UPSTREAM:
    • add comments about the changes under the (cherry picked from commit ...) line
    • Example:
        BACKPORT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        [joe: Resolved minor conflict in drivers/foo/bar.c ]
        Signed-off-by: Joe Smith <joe.smith@foo.org>

Requirements for other backports: FROMGIT:, FROMLIST:,

  • If the patch has been merged into an upstream maintainer tree, but has not yet been merged into Linux mainline
    • tag the patch subject with FROMGIT:
    • add info on where the patch came from as (cherry picked from commit <sha1> <repo> <branch>). This must be a stable maintainer branch (not rebased, so don't use linux-next for example).
    • if changes were required, use BACKPORT: FROMGIT:
    • Example:
      • if the commit message in the maintainer tree is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>
  • then Joe Smith would upload the patch for the common kernel as
        FROMGIT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        (cherry picked from commit 878a2fd9de10b03d11d2f622250285c7e63deace
         https://git.kernel.org/pub/scm/linux/kernel/git/foo/bar.git test-branch)
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch has been submitted to LKML, but not accepted into any maintainer tree
    • tag the patch subject with FROMLIST:
    • add a Link: tag with a link to the submittal on lore.kernel.org
    • add a Bug: tag with the Android bug (required for patches not accepted into a maintainer tree)
    • if changes were required, use BACKPORT: FROMLIST:
    • Example:
        FROMLIST: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Link: https://lore.kernel.org/lkml/20190619171517.GA17557@someone.com/
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>

Requirements for Android-specific patches: ANDROID:

  • If the patch is fixing a bug to Android-specific code
    • tag the patch subject with ANDROID:
    • add a Fixes: tag that cites the patch with the bug
    • Example:
        ANDROID: fix android-specific bug in foobar.c

        This is the detailed description of the important fix

        Fixes: 1234abcd2468 ("foobar: add cool feature")
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch is a new feature
    • tag the patch subject with ANDROID:
    • add a Bug: tag with the Android bug (required for android-specific features)