7f8e249dcc
Unfair rwsem should be used when blk-cg is on. Otherwise, there is regression.
FYI, we noticed a -26.7% regression of aim7.jobs-per-min due to commit:
commit: e4544b63a7ee49e7fbebf35ece0a6acd3b9617ae ("f2fs: move f2fs to use reader-unfair rwsems")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
in testcase: aim7
on test machine: 88 threads 2 sockets Intel(R) Xeon(R) Gold 6238M CPU @ 2.10GHz with 128G memory
with following parameters:
disk: 4BRD_12G
md: RAID0
fs: f2fs
test: sync_disk_rw
load: 100
cpufreq_governor: performance
ucode: 0x500320a
test-description: AIM7 is a traditional UNIX system level benchmark suite which is used to test and measure the performance of multiuser system.
test-url: https://sourceforge.net/projects/aimbench/files/aim-suite7/
Reported-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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.