linux-kernel - [PATCH 0/2] task

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Sat, 18 Jul 2020 11:32:50 +0300
From:   Pavel Begunkov <asml.silence@...il.com>
To:     Jens Axboe <axboe@...nel.dk>, io-uring@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 0/2] task_put batching

For my a bit exaggerated test case perf continues to show high CPU
cosumption by io_dismantle(), and so calling it io_iopoll_complete().
Even though the patch doesn't yield throughput increase for my setup,
probably because the effect is hidden behind polling, but it definitely
improves relative percentage. And the difference should only grow with
increasing number of CPUs. Another reason to have this is that atomics
may affect other parallel tasks (e.g. which doesn't use io_uring)

before:
io_iopoll_complete: 5.29%
io_dismantle_req:   2.16%

after:
io_iopoll_complete: 3.39%
io_dismantle_req:   0.465%

Pavel Begunkov (2):
  tasks: add put_task_struct_many()
  io_uring: batch put_task_struct()

 fs/io_uring.c              | 28 ++++++++++++++++++++++++++--
 include/linux/sched/task.h |  6 ++++++
 2 files changed, 32 insertions(+), 2 deletions(-)

-- 
2.24.0