From: Andrew Morton <akpm@linux-foundation.org>
To: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>, Andi Kleen <ak@linux.intel.com>,
linux-mm@kvack.org, Andrea Arcangeli <aarcange@redhat.com>,
tim.c.chen@linux.intel.com, torvalds@linux-foundation.org,
lwoodman@redhat.com, mel@csn.ul.ie
Subject: Re: [PATCH 1/4] VM/RMAP: Add infrastructure for batching the rmap chain locking
Date: Mon, 9 May 2011 18:48:06 -0700 [thread overview]
Message-ID: <20110509184806.112bcebd.akpm@linux-foundation.org> (raw)
In-Reply-To: <4DC89480.3060002@redhat.com>
On Mon, 09 May 2011 21:27:28 -0400 Rik van Riel <riel@redhat.com> wrote:
> On 05/09/2011 09:26 PM, Andrew Morton wrote:
> > On Tue, 10 May 2011 02:05:17 +0200 Andi Kleen<andi@firstfloor.org> wrote:
> >
> >>> hm, which atomic ops are those? We shouldn't need buslocked operations
> >>> on UP.
> >>
> >> Good point. I forgot they're patched out.
> >>
> >> Then it's likely somewhat slower, but I doubt it's a significant
> >> slowdown. Essentially it's just a few more if ()s
> >
> > And presumably some more instruction cachelines here and there. It'll
> > be small, but 100*small == large. We can reduce the overhead to zero,
> > it's a question of how ugly the end result is.
>
> More instruction cachelines, but fewer pointer dereferences
> due to not looking up the lock all the time (if the root
> anon_vma is the same).
>
Why would we be looking up a lock which doesn't exist?
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-05-10 1:41 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-05 19:32 Batch locking for rmap fork/exit processing Andi Kleen
2011-05-05 19:32 ` [PATCH 1/4] VM/RMAP: Add infrastructure for batching the rmap chain locking Andi Kleen
2011-05-06 15:59 ` Rik van Riel
2011-05-09 21:43 ` Andrew Morton
2011-05-09 22:23 ` Andi Kleen
2011-05-09 22:28 ` Andrew Morton
2011-05-09 23:02 ` Andi Kleen
2011-05-09 23:16 ` Andrew Morton
2011-05-10 0:05 ` Andi Kleen
2011-05-10 1:26 ` Andrew Morton
2011-05-10 1:27 ` Rik van Riel
2011-05-10 1:48 ` Andrew Morton [this message]
2011-05-05 19:32 ` [PATCH 2/4] VM/RMAP: Batch anon vma chain root locking in fork Andi Kleen
2011-05-06 15:59 ` Rik van Riel
2011-05-05 19:32 ` [PATCH 3/4] VM/RMAP: Batch anon_vma_unlink in exit Andi Kleen
2011-05-06 16:48 ` Rik van Riel
2011-05-05 19:32 ` [PATCH 4/4] VM/RMAP: Move avc freeing outside the lock Andi Kleen
2011-05-06 16:52 ` Rik van Riel
2011-05-06 16:44 ` Batch locking for rmap fork/exit processing Linus Torvalds
2011-05-06 17:05 ` Andi Kleen
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=20110509184806.112bcebd.akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=aarcange@redhat.com \
--cc=ak@linux.intel.com \
--cc=andi@firstfloor.org \
--cc=linux-mm@kvack.org \
--cc=lwoodman@redhat.com \
--cc=mel@csn.ul.ie \
--cc=riel@redhat.com \
--cc=tim.c.chen@linux.intel.com \
--cc=torvalds@linux-foundation.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.