From: Ingo Molnar <mingo@kernel.org>
To: Mel Gorman <mgorman@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@redhat.com>, Hugh Dickins <hughd@google.com>,
Minchan Kim <minchan@kernel.org>,
Dave Hansen <dave.hansen@intel.com>,
Andi Kleen <andi@firstfloor.org>, H Peter Anvin <hpa@zytor.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/4] mm: Send one IPI per CPU to TLB flush all entries after unmapping pages
Date: Thu, 11 Jun 2015 17:02:51 +0200 [thread overview]
Message-ID: <20150611150250.GA14086@gmail.com> (raw)
In-Reply-To: <20150610085950.GB26425@suse.de>
* Mel Gorman <mgorman@suse.de> wrote:
> > In the full-flushing case (v6 without patch 4) the batching limit is
> > 'infinite', we'll batch as long as possible, right?
>
> No because we must flush before pages are freed so the maximum batching is
> related to SWAP_CLUSTER_MAX. If we free a page before the flush then in theory
> the page can be reallocated and a stale TLB entry can allow access to unrelated
> data. It would be almost impossible to trigger corruption this way but it's a
> concern.
Well, could we say double SWAP_CLUSTER_MAX to further reduce the IPI rate?
Thanks,
Ingo
--
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/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2015-06-11 15:02 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-09 17:31 [PATCH 0/3] TLB flush multiple pages per IPI v6 Mel Gorman
2015-06-09 17:31 ` [PATCH 1/4] x86, mm: Trace when an IPI is about to be sent Mel Gorman
2015-06-09 17:31 ` [PATCH 2/4] mm: Send one IPI per CPU to TLB flush all entries after unmapping pages Mel Gorman
2015-06-09 20:01 ` Rik van Riel
2015-06-10 7:47 ` Ingo Molnar
2015-06-10 8:14 ` Mel Gorman
2015-06-10 8:21 ` Ingo Molnar
2015-06-10 8:51 ` Mel Gorman
2015-06-10 8:26 ` Ingo Molnar
2015-06-10 9:58 ` Mel Gorman
2015-06-10 8:33 ` Ingo Molnar
2015-06-10 8:59 ` Mel Gorman
2015-06-11 15:02 ` Ingo Molnar [this message]
2015-06-11 15:25 ` Mel Gorman
2015-06-09 17:31 ` [PATCH 3/4] mm: Defer flush of writable TLB entries Mel Gorman
2015-06-09 20:02 ` Rik van Riel
2015-06-10 7:50 ` Ingo Molnar
2015-06-10 8:17 ` Mel Gorman
2015-06-09 17:31 ` [PATCH 4/4] mm: Send one IPI per CPU to TLB flush pages that were recently unmapped Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2015-07-06 13:39 [PATCH 0/4] TLB flush multiple pages per IPI v7 Mel Gorman
2015-07-06 13:39 ` [PATCH 2/4] mm: Send one IPI per CPU to TLB flush all entries after unmapping pages Mel Gorman
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=20150611150250.GA14086@gmail.com \
--to=mingo@kernel.org \
--cc=a.p.zijlstra@chello.nl \
--cc=akpm@linux-foundation.org \
--cc=andi@firstfloor.org \
--cc=dave.hansen@intel.com \
--cc=hpa@zytor.com \
--cc=hughd@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=minchan@kernel.org \
--cc=riel@redhat.com \
--cc=tglx@linutronix.de \
--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 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).