Kernel for Galaxy S24, rebased on CLO sources (WIP)
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Andrea Arcangeli 25db7c13d8 UPSTREAM: mm/rmap: support move to different root anon_vma in folio_move_anon_rmap()
Patch series "userfaultfd move option", v6.

This patch series introduces UFFDIO_MOVE feature to userfaultfd, which has
long been implemented and maintained by Andrea in his local tree [1], but
was not upstreamed due to lack of use cases where this approach would be
better than allocating a new page and copying the contents.  Previous
upstraming attempts could be found at [6] and [7].

UFFDIO_COPY performs ~20% better than UFFDIO_MOVE when the application
needs pages to be allocated [2].  However, with UFFDIO_MOVE, if pages are
available (in userspace) for recycling, as is usually the case in heap
compaction algorithms, then we can avoid the page allocation and memcpy
(done by UFFDIO_COPY).  Also, since the pages are recycled in the
userspace, we avoid the need to release (via madvise) the pages back to
the kernel [3].  We see over 40% reduction (on a Google pixel 6 device) in
the compacting thread's completion time by using UFFDIO_MOVE vs.
UFFDIO_COPY.  This was measured using a benchmark that emulates a heap
compaction implementation using userfaultfd (to allow concurrent accesses
by application threads).  More details of the usecase are explained in
[3].

Furthermore, UFFDIO_MOVE enables moving swapped-out pages without
touching them within the same vma. Today, it can only be done by mremap,
however it forces splitting the vma.

TODOs for follow-up improvements:
- cross-mm support. Known differences from single-mm and missing pieces:
	- memcg recharging (might need to isolate pages in the process)
	- mm counters
	- cross-mm deposit table moves
	- cross-mm test
	- document the address space where src and dest reside in struct
	  uffdio_move

- TLB flush batching.  Will require extensive changes to PTL locking in
  move_pages_pte().  OTOH that might let us reuse parts of mremap code.

This patch (of 5):

For now, folio_move_anon_rmap() was only used to move a folio to a
different anon_vma after fork(), whereby the root anon_vma stayed
unchanged.  For that, it was sufficient to hold the folio lock when
calling folio_move_anon_rmap().

However, we want to make use of folio_move_anon_rmap() to move folios
between VMAs that have a different root anon_vma.  As folio_referenced()
performs an RMAP walk without holding the folio lock but only holding the
anon_vma in read mode, holding the folio lock is insufficient.

When moving to an anon_vma with a different root anon_vma, we'll have to
hold both, the folio lock and the anon_vma lock in write mode.
Consequently, whenever we succeeded in folio_lock_anon_vma_read() to
read-lock the anon_vma, we have to re-check if the mapping was changed in
the meantime.  If that was the case, we have to retry.

Note that folio_move_anon_rmap() must only be called if the anon page is
exclusive to a process, and must not be called on KSM folios.

This is a preparation for UFFDIO_MOVE, which will hold the folio lock, the
anon_vma lock in write mode, and the mmap_lock in read mode.

Link: https://lkml.kernel.org/r/20231206103702.3873743-1-surenb@google.com
Link: https://lkml.kernel.org/r/20231206103702.3873743-2-surenb@google.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: kernel-team@android.com
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Nicolas Geoffray <ngeoffray@google.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

(cherry picked from commit 880a99b60d467eefd96322e27b0a8c0b805dfa43)

Bug: 274911254
Change-Id: Iad9619c0273e050af26356f66ae9fc88b56d68bd
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
2024-04-22 18:09:14 +00:00
android ANDROID: abi_gki_aarch64_qcom: Update symbol list 2024-04-22 11:04:47 +05:30
arch ANDROID: gki_defconfig: Sync gki_defconfig 2024-04-22 11:02:55 +05:30
block Reapply "ANDROID: block: Add support for filesystem requests and small segments" 2024-04-17 18:38:54 +00:00
certs This is the 6.1.11 stable release 2023-02-09 13:29:55 +00:00
crypto Reapply "Merge tag 'android14-6.1.75_r00' into android14-6.1" 2024-04-02 19:49:12 +00:00
Documentation UPSTREAM: PM: hibernate: Support to select compression algorithm 2024-04-22 10:56:17 +05:30
drivers ANDROID: vendor_hooks: Add hooks to support hibernation 2024-04-22 11:04:11 +05:30
fs ANDROID: vendor_hooks: add restricted vendor hook for meminfo 2024-04-11 00:56:49 +00:00
include ANDROID: vendor_hooks: Add hooks to support hibernation 2024-04-22 11:04:11 +05:30
init Reapply "Merge tag 'android14-6.1.75_r00' into android14-6.1" 2024-04-02 19:49:12 +00:00
io_uring Reapply "Merge tag 'android14-6.1.75_r00' into android14-6.1" 2024-04-02 19:49:12 +00:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel ANDROID: PM: hibernate: Encryption support with compression 2024-04-22 11:05:17 +05:30
lib Reapply "Merge tag 'android14-6.1.75_r00' into android14-6.1" 2024-04-02 19:49:12 +00:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm UPSTREAM: mm/rmap: support move to different root anon_vma in folio_move_anon_rmap() 2024-04-22 18:09:14 +00:00
net UPSTREAM: netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path 2024-04-15 11:20:28 +00:00
rust rust: allocator: Prevent mis-aligned allocation 2023-08-11 12:08:18 +02:00
samples Merge 6.1.60 into android14-6.1-lts 2023-11-03 16:23:47 +00:00
scripts Reapply "Merge tag 'android14-6.1.75_r00' into android14-6.1" 2024-04-02 19:49:12 +00:00
security Reapply "Merge tag 'android14-6.1.75_r00' into android14-6.1" 2024-04-02 19:49:12 +00:00
sound UPSTREAM: ALSA: virtio: Fix "Coverity: virtsnd_kctl_tlv_op(): Uninitialized variables" warning. 2024-04-04 15:35:58 +00:00
tools Reapply "Merge tag 'android14-6.1.75_r00' into android14-6.1" 2024-04-02 19:49:12 +00:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add() 2023-09-13 09:42:46 +02:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore ANDROID: add Android KABI build files to root .gitignore file 2023-06-09 13:12:00 +00:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
BUILD.bazel ANDROID: Add known structs used by modules to KMI 2024-04-16 13:49:35 -07:00
build.config.aarch64 ANDROID: Move NDK_TRIPLE to build.config.constants. 2023-02-14 14:13:51 -08:00
build.config.allmodconfig ANDROID: Revert "ANDROID: allmodconfig: disable WERROR" 2023-08-21 17:29:29 +01:00
build.config.allmodconfig.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.allmodconfig.arm ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.allmodconfig.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.amlogic ANDROID: Unnest MAKE_GOALS from build configs 2023-05-02 13:37:21 +00:00
build.config.arm ANDROID: kleaf: move NDK_TRIPLE for arm to build.config.constants. 2023-05-09 22:36:11 +00:00
build.config.common ANDROID: 6/16/2023 KMI update 2023-06-16 20:49:51 +00:00
build.config.constants ANDROID: clang: update to 17.0.2 2023-05-15 18:53:36 +00:00
build.config.crashdump ANDROID: Move microdroid and crashdump defconfigs to common 2023-09-27 15:30:26 +00:00
build.config.crashdump.aarch64 ANDROID: Move microdroid and crashdump defconfigs to common 2023-09-27 15:30:26 +00:00
build.config.crashdump.x86_64 ANDROID: Move microdroid and crashdump defconfigs to common 2023-09-27 15:30:26 +00:00
build.config.db845c Reapply "Merge tag 'android14-6.1.75_r00' into android14-6.1" 2024-04-02 19:49:12 +00:00
build.config.gki ANDROID: GKI: Source GKI_BUILD_CONFIG_FRAGMENT after setting all variables 2022-12-27 13:52:08 -08:00
build.config.gki_kasan ANDROID: build.config: re-disable LTO properly for KASAN 2022-03-24 12:41:35 -07:00
build.config.gki_kasan.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.gki_kasan.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.gki_kprobes ANDROID: build.configs: migrate away from CC_LD_ARG 2021-07-02 09:49:23 +00:00
build.config.gki_kprobes.aarch64 ANDROID: Adding kprobes build configs for Cuttlefish 2021-03-01 15:29:45 +00:00
build.config.gki_kprobes.x86_64 ANDROID: Adding kprobes build configs for Cuttlefish 2021-03-01 15:29:45 +00:00
build.config.gki-debug.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.gki-debug.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-08-31 15:20:37 +00:00
build.config.gki.aarch64 ANDROID: Delete MODULES_LIST from build configs. 2023-06-21 11:18:02 +00:00
build.config.gki.aarch64.fips140 ANDROID: remove LTO check from build.config.gki.aarch64.fips140 2024-03-04 11:19:25 +00:00
build.config.gki.riscv64 ANDROID: Delete MODULES_LIST from build configs. 2023-06-21 11:18:02 +00:00
build.config.gki.x86_64 ANDROID: Delete MODULES_LIST from build configs. 2023-06-21 11:18:02 +00:00
build.config.khwasan ANDROID: Add a build config fragment for KHWASan. 2021-10-13 19:44:44 +00:00
build.config.microdroid ANDROID: Move microdroid and crashdump defconfigs to common 2023-09-27 15:30:26 +00:00
build.config.microdroid.aarch64 ANDROID: Move microdroid and crashdump defconfigs to common 2023-09-27 15:30:26 +00:00
build.config.microdroid.x86_64 ANDROID: Move microdroid and crashdump defconfigs to common 2023-09-27 15:30:26 +00:00
build.config.riscv64 ANDROID: GKI: Add 64-bit RISC-V config 2022-12-08 20:01:15 +00:00
build.config.rockchip ANDROID: GKI: Add rockchip fragment and build.config 2023-09-19 17:36:15 +00:00
build.config.rockpi4 ANDROID: db845c: Remove MAKE_GOALS from build.config 2023-05-15 07:01:39 +00:00
build.config.x86_64 ANDROID: Move NDK_TRIPLE to build.config.constants. 2023-02-14 14:13:51 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig ANDROID: kbuild: add Kconfig support for external modules 2021-12-13 18:33:18 +00:00
Kconfig.ext ANDROID: kbuild: add Kconfig support for external modules 2021-12-13 18:33:18 +00:00
MAINTAINERS Reapply "Merge tag 'android14-6.1.75_r00' into android14-6.1" 2024-04-02 19:49:12 +00:00
Makefile Reapply "Merge tag 'android14-6.1.75_r00' into android14-6.1" 2024-04-02 19:49:12 +00:00
modules.bzl Revert "ANDROID: Build null_blk and scsi_debug as kernel modules" 2024-02-29 10:22:01 -08:00
OWNERS ANDROID: Enable GKI Dr. No Enforcement 2023-06-15 09:54:33 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
README.md ANDROID: README.md: fix checkpatch.pl path typo 2021-04-07 23:16:50 +00:00

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 scripts/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)