linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Russell King <linux@arm.linux.org.uk>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
	Paul Turner <pjt@google.com>, Andrew Hunter <ahh@google.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Andi Kleen <andi@firstfloor.org>,
	Dave Watson <davejwatson@fb.com>, Chris Lameter <cl@linux.com>,
	Ben Maurer <bmaurer@fb.com>, Steven Rostedt <rostedt@goodmis.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Josh Triplett <josh@joshtriplett.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Michael Kerrisk <mtk.manpages@gmail.com>
Subject: Re: [PATCH v4 1/5] getcpu_cache system call: cache CPU number of running thread
Date: Thu, 25 Feb 2016 10:56:35 +0100	[thread overview]
Message-ID: <20160225095635.GO6356@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1456270120-7560-2-git-send-email-mathieu.desnoyers@efficios.com>

On Tue, Feb 23, 2016 at 06:28:36PM -0500, Mathieu Desnoyers wrote:
> This approach is inspired by Paul Turner and Andrew Hunter's work
> on percpu atomics, which lets the kernel handle restart of critical
> sections. [1] [2]

So I'd like a few extra words on the intersection with that work.

Yes, that also needs a CPU number, but that needs a little extra as
well. Can this work be extended to provide the little extra and is the
getcpu name still sane in that case?

Alternatively, could you not, at equal speed, get the CPU number from
the restartable sequence data?

That is, do explain why we want both.

(And remind Paul to keep pushing that)

  parent reply	other threads:[~2016-02-25  9:57 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-23 23:28 [PATCH v4 0/5] getcpu_cache system call for 4.6 Mathieu Desnoyers
2016-02-23 23:28 ` [PATCH v4 1/5] getcpu_cache system call: cache CPU number of running thread Mathieu Desnoyers
2016-02-24 11:11   ` Thomas Gleixner
2016-02-24 17:17     ` Mathieu Desnoyers
2016-02-25 23:32     ` Rasmus Villemoes
2016-02-26 17:47       ` Mathieu Desnoyers
2016-02-25  9:56   ` Peter Zijlstra [this message]
2016-02-25 16:55     ` Mathieu Desnoyers
2016-02-25 17:04       ` Peter Zijlstra
2016-02-25 17:17         ` Mathieu Desnoyers
2016-02-26 11:33           ` Peter Zijlstra
2016-02-26 16:29             ` Thomas Gleixner
2016-02-26 17:20               ` Mathieu Desnoyers
2016-02-26 18:01                 ` Thomas Gleixner
2016-02-26 20:24                   ` Mathieu Desnoyers
2016-02-26 23:04                     ` H. Peter Anvin
2016-02-27  0:40                       ` Mathieu Desnoyers
2016-02-27  6:24                         ` H. Peter Anvin
2016-02-27 14:15                           ` Mathieu Desnoyers
2016-02-27 14:58                             ` Peter Zijlstra
2016-02-27 18:35                               ` Linus Torvalds
2016-02-27 19:01                                 ` H. Peter Anvin
2016-02-27 23:53                                 ` Mathieu Desnoyers
     [not found]                                   ` <CA+55aFwcgwRxvVBz5kk_3O8dESXAGJ4KHBkf=pSXjiS7Xh4NwA@mail.gmail.com>
     [not found]                                     ` <1082926946.10326.1456619994590.JavaMail.zimbra@efficios.com>
2016-02-28  0:57                                       ` Linus Torvalds
2016-02-28 14:32                                         ` Mathieu Desnoyers
2016-02-29 10:35                                           ` Peter Zijlstra
2016-03-01 20:23                                             ` Mathieu Desnoyers
2016-03-01 21:32                                               ` Peter Zijlstra
2016-03-01 21:36                                                 ` Peter Zijlstra
2016-03-01 21:47                                                 ` H. Peter Anvin
2016-03-02 10:34                                                   ` Peter Zijlstra
2016-02-29 10:32                                       ` Peter Zijlstra
2016-02-29 10:39                                         ` Arnd Bergmann
2016-02-29 12:41                                           ` Mathieu Desnoyers
2016-02-29 13:08                                             ` Arnd Bergmann
2016-02-29 18:19                                             ` H. Peter Anvin
2016-03-02 10:44                                             ` Geert Uytterhoeven
2016-03-01 18:25                                       ` H. Peter Anvin
2016-03-01 18:40                                         ` Mathieu Desnoyers
2016-02-28 13:07                                 ` Geert Uytterhoeven
2016-02-28 16:21                                   ` Linus Torvalds
2016-02-29 10:01                                 ` Peter Zijlstra
2016-02-27 15:04                             ` H. Peter Anvin
2016-02-23 23:28 ` [PATCH v4 2/5] getcpu_cache: ARM resume notifier Mathieu Desnoyers
2016-02-23 23:28 ` [PATCH v4 3/5] getcpu_cache: wire up ARM system call Mathieu Desnoyers
2016-02-24  0:54   ` kbuild test robot
2016-02-24  1:05   ` [PATCH v4 (updated)] " Mathieu Desnoyers
2016-02-24  5:28     ` kbuild test robot
2016-02-24  6:54     ` kbuild test robot
2016-02-23 23:28 ` [PATCH v4 4/5] getcpu_cache: x86 32/64 resume notifier Mathieu Desnoyers
2016-02-23 23:28 ` [PATCH v4 5/5] getcpu_cache: wire up x86 32/64 system call Mathieu Desnoyers
2016-02-24  1:36 ` [PATCH v4 0/5] getcpu_cache system call for 4.6 H. Peter Anvin
2016-02-24  4:09   ` Mathieu Desnoyers
2016-02-24 20:07     ` H. Peter Anvin
2016-02-24 22:38       ` Mathieu Desnoyers

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=20160225095635.GO6356@twins.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=ahh@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=andi@firstfloor.org \
    --cc=bmaurer@fb.com \
    --cc=catalin.marinas@arm.com \
    --cc=cl@linux.com \
    --cc=davejwatson@fb.com \
    --cc=hpa@zytor.com \
    --cc=josh@joshtriplett.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@arm.linux.org.uk \
    --cc=luto@amacapital.net \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=mingo@redhat.com \
    --cc=mtk.manpages@gmail.com \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=pjt@google.com \
    --cc=rostedt@goodmis.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=will.deacon@arm.com \
    /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).