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Yin Fengwei c8be038067 filemap: add filemap_map_order0_folio() to handle order0 folio
Kernel test robot reported regressions for several benchmarks [1].
The regression are related with commit:
de74976eb6 ("filemap: add filemap_map_folio_range()")

It turned out that function filemap_map_folio_range() brings these
regressions when handle folio with order0.

Add filemap_map_order0_folio() to handle order0 folio. The benefit
come from two perspectives:
  - the code size is smaller (around 126 bytes)
  - no loop

Testing showed the regressions reported by 0day [1] all are fixed:
commit 9f1f5b60e7: parent commit of de74976eb6
commit fbdf9263a3d7fdbd: latest mm-unstable commit
commit 7fbfe2003f84686d: this fixing patch

9f1f5b60e7 fbdf9263a3d7fdbd            7fbfe2003f84686d
---------------- --------------------------- ---------------------------
   3843810           -21.4%    3020268            +4.6%    4018708      stress-ng.bad-altstack.ops
     64061           -21.4%      50336            +4.6%      66977      stress-ng.bad-altstack.ops_per_sec

   1709026           -14.4%    1462102            +2.4%    1750757      stress-ng.fork.ops
     28483           -14.4%      24368            +2.4%      29179      stress-ng.fork.ops_per_sec

   3685088           -53.6%    1710976            +0.5%    3702454      stress-ng.zombie.ops
     56732           -65.3%      19667            +0.7%      57107      stress-ng.zombie.ops_per_sec

     61874           -12.1%      54416            +0.4%      62136      vm-scalability.median
  13527663           -11.7%   11942117            -0.1%   13513946      vm-scalability.throughput
 4.066e+09           -11.7%   3.59e+09            -0.1%  4.061e+09      vm-scalability.workload

[1]:
https://lore.kernel.org/oe-lkp/72e017b9-deb6-44fa-91d6-716ee2c39cbc@intel.com/T/#m7d2bba30f75a9cee8eab07e5809abd9b3b206c84

Link: https://lkml.kernel.org/r/20230914134741.1937654-1-fengwei.yin@intel.com
Fixes: de74976eb6 ("filemap: add filemap_map_folio_range()")
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202309111556.b2aa3d7a-oliver.sang@intel.com
Cc: Feng Tang <feng.tang@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-19 13:21:34 -07:00
arch sh: mm: re-add lost __ref to ioremap_prot() to fix modpost warning 2023-09-19 13:21:32 -07:00
block blk-mq: fix tags UAF when shrinking q->nr_hw_queues 2023-09-11 16:17:34 -06:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto This update includes the following changes: 2023-08-29 11:23:29 -07:00
Documentation Driver core fix for 6.6-rc2 2023-09-16 11:26:52 -07:00
drivers SCSI fixes on 20230916 2023-09-16 11:54:48 -07:00
fs proc: nommu: /proc/<pid>/maps: release mmap read lock 2023-09-19 13:21:34 -07:00
include mm: memcontrol: fix GFP_NOFS recursion in memory.high enforcement 2023-09-19 13:21:34 -07:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring io_uring/net: fix iter retargeting for selected buf 2023-09-14 10:12:55 -06:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel pidfd: prevent a kernel-doc warning 2023-09-19 13:21:33 -07:00
lib argv_split: fix kernel-doc warnings 2023-09-19 13:21:33 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm filemap: add filemap_map_order0_folio() to handle order0 folio 2023-09-19 13:21:34 -07:00
net kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg(). 2023-09-14 10:43:51 +02:00
rust Documentation work keeps chugging along; stuff for 6.6 includes: 2023-08-30 20:05:42 -07:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts revert "scripts/gdb/symbols: add specific ko module load command" 2023-09-19 13:21:33 -07:00
security selinux: fix handling of empty opts in selinux_fs_context_submount() 2023-09-12 17:31:08 -04:00
sound sound fixes for 6.6-rc1 2023-09-08 13:07:50 -07:00
tools selftests/proc: fixup proc-empty-vm test after KSM changes 2023-09-19 13:21:33 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap for-linus-2023083101 2023-09-01 12:31:44 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS This pull-request renames the genpd subsystem to pmdomain. 2023-09-13 14:18:19 -07:00
Makefile Linux 6.6-rc2 2023-09-17 14:40:24 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.