From: riel@redhat.com
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, williams@redhat.com, luto@kernel.org,
mingo@kernel.org, bonzini@redhat.com, fweisbec@redhat.com,
peterz@infradead.org, heiko.carstens@de.ibm.com,
tglx@linutronix.de
Subject: [PATCH 0/3] reduce nohz_full syscall overhead by 10%
Date: Thu, 30 Apr 2015 17:23:52 -0400 [thread overview]
Message-ID: <1430429035-25563-1-git-send-email-riel@redhat.com> (raw)
Profiling reveals that a lot of the overhead from the nohz_full
accounting seems to come not from the accounting itself, but from
disabling and re-enabling interrupts.
This patch series removes the interrupt disabling & re-enabling
from __acct_update_integrals, which is called on both syscall
entry and exit, as well as from the user_exit called on syscall
entry.
Together they speed up a benchmark that calls getpriority in
a row 10 million times by about 10%:
run time system time
vanilla 5.49s 2.08s
__acct patch 5.21s 1.92s
both patches 4.88s 1.71s
next reply other threads:[~2015-04-30 21:24 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-30 21:23 riel [this message]
2015-04-30 21:23 ` [PATCH 1/3] reduce indentation in __acct_update_integrals riel
2015-04-30 21:23 ` [PATCH 2/3] remove local_irq_save from __acct_update_integrals riel
2015-04-30 21:23 ` [PATCH 3/3] context_tracking,x86: remove extraneous irq disable & enable from context tracking on syscall entry riel
2015-04-30 21:56 ` Andy Lutomirski
2015-05-01 6:40 ` Ingo Molnar
2015-05-01 15:20 ` Rik van Riel
2015-05-01 15:59 ` Ingo Molnar
2015-05-01 16:03 ` Andy Lutomirski
2015-05-01 16:21 ` Ingo Molnar
2015-05-01 16:26 ` Rik van Riel
2015-05-01 16:34 ` Ingo Molnar
2015-05-01 18:05 ` Rik van Riel
2015-05-01 18:40 ` Ingo Molnar
2015-05-01 19:11 ` Rik van Riel
2015-05-01 19:37 ` Andy Lutomirski
2015-05-02 5:27 ` Ingo Molnar
2015-05-02 18:27 ` Rik van Riel
2015-05-03 18:41 ` Andy Lutomirski
2015-05-07 10:35 ` Ingo Molnar
2015-05-04 9:26 ` Paolo Bonzini
2015-05-04 13:30 ` Rik van Riel
2015-05-04 14:06 ` Rik van Riel
2015-05-04 14:19 ` Rik van Riel
2015-05-04 15:59 ` question about RCU dynticks_nesting Rik van Riel
2015-05-04 18:39 ` Paul E. McKenney
2015-05-04 19:39 ` Rik van Riel
2015-05-04 20:02 ` Paul E. McKenney
2015-05-04 20:13 ` Rik van Riel
2015-05-04 20:38 ` Paul E. McKenney
2015-05-04 20:53 ` Rik van Riel
2015-05-05 5:54 ` Paul E. McKenney
2015-05-06 1:49 ` Mike Galbraith
2015-05-06 3:44 ` Mike Galbraith
2015-05-06 6:06 ` Paul E. McKenney
2015-05-06 6:52 ` Mike Galbraith
2015-05-06 7:01 ` Mike Galbraith
2015-05-07 0:59 ` Frederic Weisbecker
2015-05-07 15:44 ` Rik van Riel
2015-05-04 19:00 ` Rik van Riel
2015-05-04 19:39 ` Paul E. McKenney
2015-05-04 19:59 ` Rik van Riel
2015-05-04 20:40 ` Paul E. McKenney
2015-05-05 10:53 ` Peter Zijlstra
2015-05-05 12:34 ` Paul E. McKenney
2015-05-05 13:00 ` Peter Zijlstra
2015-05-05 18:35 ` Paul E. McKenney
2015-05-05 21:09 ` Rik van Riel
2015-05-06 5:41 ` Paul E. McKenney
2015-05-05 10:48 ` Peter Zijlstra
2015-05-05 10:51 ` Peter Zijlstra
2015-05-05 12:30 ` Paul E. McKenney
2015-05-02 4:06 ` [PATCH 3/3] context_tracking,x86: remove extraneous irq disable & enable from context tracking on syscall entry Mike Galbraith
2015-05-01 16:37 ` Ingo Molnar
2015-05-01 16:40 ` Rik van Riel
2015-05-01 16:45 ` Ingo Molnar
2015-05-01 16:54 ` Rik van Riel
2015-05-01 17:12 ` Ingo Molnar
2015-05-01 17:22 ` Rik van Riel
2015-05-01 17:59 ` Ingo Molnar
2015-05-01 16:22 ` Rik van Riel
2015-05-01 16:27 ` Ingo Molnar
2015-05-03 13:23 ` Mike Galbraith
2015-05-03 17:30 ` Rik van Riel
2015-05-03 18:24 ` Andy Lutomirski
2015-05-03 18:52 ` Rik van Riel
2015-05-07 10:48 ` Ingo Molnar
2015-05-07 12:18 ` Frederic Weisbecker
2015-05-07 12:29 ` Ingo Molnar
2015-05-07 15:47 ` Rik van Riel
2015-05-08 7:58 ` Ingo Molnar
2015-05-07 12:22 ` Andy Lutomirski
2015-05-07 12:44 ` Ingo Molnar
2015-05-07 12:49 ` Ingo Molnar
2015-05-08 6:17 ` Paul E. McKenney
2015-05-07 12:52 ` Andy Lutomirski
2015-05-07 15:08 ` Ingo Molnar
2015-05-07 17:47 ` Andy Lutomirski
2015-05-08 6:37 ` Ingo Molnar
2015-05-08 10:59 ` Andy Lutomirski
2015-05-08 11:27 ` Ingo Molnar
2015-05-08 12:56 ` Andy Lutomirski
2015-05-08 13:27 ` Ingo Molnar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1430429035-25563-1-git-send-email-riel@redhat.com \
--to=riel@redhat.com \
--cc=bonzini@redhat.com \
--cc=fweisbec@redhat.com \
--cc=heiko.carstens@de.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=williams@redhat.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).