Chengming Zhou 94ace3fec8 mm/zswap: change zswap_pool kref to percpu_ref
All zswap entries will take a reference of zswap_pool when zswap_store(),
and drop it when free.  Change it to use the percpu_ref is better for
scalability performance.

Although percpu_ref use a bit more memory which should be ok for our use
case, since we almost have only one zswap_pool to be using.  The
performance gain is for zswap_store/load hotpath.

Testing kernel build (32 threads) in tmpfs with memory.max=2GB.  (zswap
shrinker and writeback enabled with one 50GB swapfile, on a 128 CPUs
x86-64 machine, below is the average of 5 runs)

        mm-unstable  zswap-global-lru
real    63.20        63.12
user    1061.75      1062.95
sys     268.74       264.44

[chengming.zhou@linux.dev: fix zswap_pools_lock usages after changing to percpu_ref]
  Link: https://lkml.kernel.org/r/20240228154954.3028626-1-chengming.zhou@linux.dev
Link: https://lkml.kernel.org/r/20240210-zswap-global-lru-v3-2-200495333595@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04 17:01:13 -08:00
2023-12-20 19:26:31 -05:00
2022-09-28 09:02:20 +02:00
2024-02-18 12:56:25 -08:00

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.
S
Description
No description provided
Readme
5.7 GiB
Languages
C 96.9%
Assembly 0.9%
Rust 0.6%
Shell 0.6%
Python 0.5%
Other 0.3%