From: Minchan Kim <minchan@kernel.org>
To: Arun Sharma <asharma@fb.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
Paul Turner <pjt@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
John Stultz <john.stultz@linaro.org>,
Christoph Lameter <cl@linux.com>,
Android Kernel Team <kernel-team@android.com>,
Robert Love <rlove@google.com>, Mel Gorman <mel@csn.ul.ie>,
Hugh Dickins <hughd@google.com>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Rik van Riel <riel@redhat.com>,
Dave Chinner <david@fromorbit.com>, Neil Brown <neilb@suse.de>,
Mike Hommey <mh@glandium.org>, Taras Glek <tglek@mozilla.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
sanjay@google.com, David Rientjes <rientjes@google.com>
Subject: Re: [RFC v2] Support volatile range for anon vma
Date: Tue, 6 Nov 2012 10:49:32 +0900 [thread overview]
Message-ID: <20121106014932.GA4623@barrios> (raw)
In-Reply-To: <20121105235443.GA27718@dev3310.snc6.facebook.com>
Hello,
On Mon, Nov 05, 2012 at 03:54:43PM -0800, Arun Sharma wrote:
> On Wed, Oct 31, 2012 at 06:56:05PM -0400, KOSAKI Motohiro wrote:
> > glibc malloc discard freed memory by using MADV_DONTNEED
> > as tcmalloc. and it is often a source of large performance decrease.
> > because of MADV_DONTNEED discard memory immediately and
> > right after malloc() call fall into page fault and pagesize memset() path.
> > then, using DONTNEED increased zero fill and cache miss rate.
>
> The memcg based solution that I posted a few months ago is working well
> for us. We see significantly less cpu in zero'ing pages.
>
> Not everyone was comfortable with the security implications of recycling
> pages between processes in a memcg, although it was disabled by default
> and had to be explicitly opted-in.
>
> Also, memory allocators have a second motivation in using madvise: to
> create virtually contiguous regions of memory from a fragmented address
> space, without increasing the RSS.
I don't get it. How do we create contiguos region by madvise?
Just out of curiosity.
Could you elaborate that use case? :)
>
> -Arun
>
> --
> 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>
--
Kind Regards,
Minchan Kim
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Minchan Kim <minchan@kernel.org>
To: Arun Sharma <asharma@fb.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
Paul Turner <pjt@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
John Stultz <john.stultz@linaro.org>,
Christoph Lameter <cl@linux.com>,
Android Kernel Team <kernel-team@android.com>,
Robert Love <rlove@google.com>, Mel Gorman <mel@csn.ul.ie>,
Hugh Dickins <hughd@google.com>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Rik van Riel <riel@redhat.com>,
Dave Chinner <david@fromorbit.com>, Neil Brown <neilb@suse.de>,
Mike Hommey <mh@glandium.org>, Taras Glek <tglek@mozilla.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
sanjay@google.com, David Rientjes <rientjes@google.com>
Subject: Re: [RFC v2] Support volatile range for anon vma
Date: Tue, 6 Nov 2012 10:49:32 +0900 [thread overview]
Message-ID: <20121106014932.GA4623@barrios> (raw)
In-Reply-To: <20121105235443.GA27718@dev3310.snc6.facebook.com>
Hello,
On Mon, Nov 05, 2012 at 03:54:43PM -0800, Arun Sharma wrote:
> On Wed, Oct 31, 2012 at 06:56:05PM -0400, KOSAKI Motohiro wrote:
> > glibc malloc discard freed memory by using MADV_DONTNEED
> > as tcmalloc. and it is often a source of large performance decrease.
> > because of MADV_DONTNEED discard memory immediately and
> > right after malloc() call fall into page fault and pagesize memset() path.
> > then, using DONTNEED increased zero fill and cache miss rate.
>
> The memcg based solution that I posted a few months ago is working well
> for us. We see significantly less cpu in zero'ing pages.
>
> Not everyone was comfortable with the security implications of recycling
> pages between processes in a memcg, although it was disabled by default
> and had to be explicitly opted-in.
>
> Also, memory allocators have a second motivation in using madvise: to
> create virtually contiguous regions of memory from a fragmented address
> space, without increasing the RSS.
I don't get it. How do we create contiguos region by madvise?
Just out of curiosity.
Could you elaborate that use case? :)
>
> -Arun
>
> --
> 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>
--
Kind Regards,
Minchan Kim
next prev parent reply other threads:[~2012-11-06 1:49 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-30 1:29 [RFC v2] Support volatile range for anon vma Minchan Kim
2012-10-30 1:29 ` Minchan Kim
2012-10-31 21:35 ` Andrew Morton
2012-10-31 21:35 ` Andrew Morton
2012-10-31 21:59 ` Paul Turner
2012-10-31 21:59 ` Paul Turner
2012-10-31 22:56 ` KOSAKI Motohiro
2012-10-31 22:56 ` KOSAKI Motohiro
2012-11-01 1:15 ` Paul Turner
2012-11-01 1:15 ` Paul Turner
2012-11-01 1:46 ` Minchan Kim
2012-11-01 1:46 ` Minchan Kim
2012-11-01 1:25 ` Minchan Kim
2012-11-01 1:25 ` Minchan Kim
2012-11-01 2:01 ` KOSAKI Motohiro
2012-11-01 2:01 ` KOSAKI Motohiro
2012-11-05 23:54 ` Arun Sharma
2012-11-05 23:54 ` Arun Sharma
2012-11-06 1:49 ` Minchan Kim [this message]
2012-11-06 1:49 ` Minchan Kim
2012-11-06 2:03 ` Arun Sharma
2012-11-06 2:03 ` Arun Sharma
2012-11-01 0:50 ` Minchan Kim
2012-11-01 0:50 ` Minchan Kim
2012-11-01 1:22 ` Paul Turner
2012-11-01 1:22 ` Paul Turner
2012-11-01 1:33 ` Minchan Kim
2012-11-01 1:33 ` Minchan Kim
2012-11-01 0:21 ` Minchan Kim
2012-11-01 0:21 ` Minchan Kim
2012-11-02 1:43 ` Bob Liu
2012-11-02 1:43 ` Bob Liu
2012-11-02 2:37 ` Minchan Kim
2012-11-02 2:37 ` Minchan Kim
2012-11-22 0:36 ` John Stultz
2012-11-22 0:36 ` John Stultz
2012-11-29 4:18 ` John Stultz
2012-11-29 4:18 ` John Stultz
2012-12-04 0:00 ` Minchan Kim
2012-12-04 0:00 ` Minchan Kim
2012-12-04 0:57 ` John Stultz
2012-12-04 0:57 ` John Stultz
2012-12-04 7:22 ` Minchan Kim
2012-12-04 7:22 ` Minchan Kim
2012-12-04 19:13 ` John Stultz
2012-12-04 19:13 ` John Stultz
2012-12-05 4:18 ` Minchan Kim
2012-12-05 4:18 ` Minchan Kim
2012-12-08 0:49 ` John Stultz
2012-12-08 0:49 ` John Stultz
2012-12-11 4:40 ` Minchan Kim
2012-12-11 4:40 ` Minchan Kim
2012-12-05 7:01 ` Minchan Kim
2012-12-05 7:01 ` Minchan Kim
2012-12-08 0:20 ` John Stultz
2012-12-08 0:20 ` John Stultz
2012-12-11 4:34 ` Minchan Kim
2012-12-11 4:34 ` Minchan Kim
2012-12-03 23:50 ` Minchan Kim
2012-12-03 23:50 ` Minchan Kim
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