From: Eric Dumazet <eric.dumazet@gmail.com>
To: Christoph Lameter <cl@linux.com>
Cc: Nitin Gupta <ngupta@vflare.org>,
Pekka Enberg <penberg@cs.helsinki.fi>,
Minchan Kim <minchan.kim@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Greg KH <greg@kroah.com>,
Linux Driver Project <devel@driverdev.osuosl.org>,
linux-mm <linux-mm@kvack.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 03/10] Use percpu stats
Date: Wed, 01 Sep 2010 22:38:15 +0200 [thread overview]
Message-ID: <1283373495.2484.41.camel@edumazet-laptop> (raw)
In-Reply-To: <alpine.DEB.2.00.1009011501230.16013@router.home>
Le mercredi 01 septembre 2010 à 15:05 -0500, Christoph Lameter a écrit :
> The problem only exists on 32 bit platforms using 64 bit counters. If you
> would provide this functionality for the fallback case of 64 bit counters
> (here x86) in 32 bit arch code then you could use the this_cpu_*
> operations in all context without your special code being replicated in
> ohter places.
>
> The additional advantage would be that for the 64bit case you would have
> much faster and more compact code.
>
>
My implementation is portable and use existing infrastructure, at the
time it was coded. BTW, its fast on 64bit too. As fast as previous
implementation. No extra code added. Please double check.
If you believe you can do better, please do so.
Of course, we added 64bit network stats to all 32bit arches only because
cost was acceptable. (I say all 32bit arches, because you seem to think
only x86 was the target)
Using this_cpu_{add|res}() fallback using atomic ops or spinlocks would
be slower than actual implemenation (smp_wmb() (nops on x86) and
increments).
WARNING: multiple messages have this Message-ID (diff)
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Christoph Lameter <cl@linux.com>
Cc: Nitin Gupta <ngupta@vflare.org>,
Pekka Enberg <penberg@cs.helsinki.fi>,
Minchan Kim <minchan.kim@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Greg KH <greg@kroah.com>,
Linux Driver Project <devel@driverdev.osuosl.org>,
linux-mm <linux-mm@kvack.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 03/10] Use percpu stats
Date: Wed, 01 Sep 2010 22:38:15 +0200 [thread overview]
Message-ID: <1283373495.2484.41.camel@edumazet-laptop> (raw)
In-Reply-To: <alpine.DEB.2.00.1009011501230.16013@router.home>
Le mercredi 01 septembre 2010 A 15:05 -0500, Christoph Lameter a A(C)crit :
> The problem only exists on 32 bit platforms using 64 bit counters. If you
> would provide this functionality for the fallback case of 64 bit counters
> (here x86) in 32 bit arch code then you could use the this_cpu_*
> operations in all context without your special code being replicated in
> ohter places.
>
> The additional advantage would be that for the 64bit case you would have
> much faster and more compact code.
>
>
My implementation is portable and use existing infrastructure, at the
time it was coded. BTW, its fast on 64bit too. As fast as previous
implementation. No extra code added. Please double check.
If you believe you can do better, please do so.
Of course, we added 64bit network stats to all 32bit arches only because
cost was acceptable. (I say all 32bit arches, because you seem to think
only x86 was the target)
Using this_cpu_{add|res}() fallback using atomic ops or spinlocks would
be slower than actual implemenation (smp_wmb() (nops on x86) and
increments).
--
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:[~2010-09-01 20:38 UTC|newest]
Thread overview: 137+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-09 17:26 [PATCH 00/10] zram: various improvements and cleanups Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 17:26 ` [PATCH 01/10] Replace ioctls with sysfs interface Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 18:34 ` Pekka Enberg
2010-08-09 18:34 ` Pekka Enberg
2010-08-10 3:06 ` Nitin Gupta
2010-08-10 3:06 ` Nitin Gupta
2010-08-31 23:06 ` Dave Hansen
2010-08-31 23:06 ` Dave Hansen
2010-08-09 17:26 ` [PATCH 02/10] Remove need for explicit device initialization Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 18:36 ` Pekka Enberg
2010-08-09 18:36 ` Pekka Enberg
2010-08-10 3:38 ` Nitin Gupta
2010-08-10 3:38 ` Nitin Gupta
2010-08-09 17:26 ` [PATCH 03/10] Use percpu stats Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 18:44 ` Pekka Enberg
2010-08-09 18:44 ` Pekka Enberg
2010-08-10 4:34 ` Andrew Morton
2010-08-10 4:34 ` Andrew Morton
2010-08-11 16:39 ` Nitin Gupta
2010-08-11 16:39 ` Nitin Gupta
2010-08-11 17:18 ` Andrew Morton
2010-08-11 17:18 ` Andrew Morton
2010-08-30 16:20 ` Christoph Lameter
2010-08-30 16:20 ` Christoph Lameter
2010-08-31 20:31 ` Nitin Gupta
2010-08-31 20:31 ` Nitin Gupta
2010-08-31 21:28 ` Eric Dumazet
2010-08-31 21:28 ` Eric Dumazet
2010-08-31 21:35 ` Christoph Lameter
2010-08-31 21:35 ` Christoph Lameter
2010-08-31 21:41 ` Eric Dumazet
2010-08-31 21:41 ` Eric Dumazet
2010-09-01 20:05 ` Christoph Lameter
2010-09-01 20:05 ` Christoph Lameter
2010-09-01 20:38 ` Eric Dumazet [this message]
2010-09-01 20:38 ` Eric Dumazet
2010-09-02 0:34 ` Christoph Lameter
2010-09-02 0:34 ` Christoph Lameter
2010-08-31 5:36 ` Anton Blanchard
2010-08-31 5:36 ` Anton Blanchard
2010-09-01 3:41 ` Anton Blanchard
2010-09-01 3:41 ` Anton Blanchard
2010-09-01 3:51 ` Anton Blanchard
2010-09-01 3:51 ` Anton Blanchard
2010-09-17 20:59 ` Andrew Morton
2010-09-17 20:59 ` Andrew Morton
2010-08-09 17:26 ` [PATCH 04/10] Use percpu buffers Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 18:57 ` Pekka Enberg
2010-08-09 18:57 ` Pekka Enberg
2010-08-10 4:47 ` Nitin Gupta
2010-08-10 4:47 ` Nitin Gupta
2010-08-10 5:05 ` Pekka Enberg
2010-08-10 5:05 ` Pekka Enberg
2010-08-10 5:32 ` Nitin Gupta
2010-08-10 5:32 ` Nitin Gupta
2010-08-10 7:36 ` Pekka Enberg
2010-08-10 7:36 ` Pekka Enberg
2010-08-09 17:26 ` [PATCH 05/10] Reduce per table entry overhead by 4 bytes Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 18:59 ` Pekka Enberg
2010-08-09 18:59 ` Pekka Enberg
2010-08-10 4:55 ` Nitin Gupta
2010-08-10 4:55 ` Nitin Gupta
2010-08-09 17:26 ` [PATCH 06/10] Block discard support Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 19:03 ` Pekka Enberg
2010-08-09 19:03 ` Pekka Enberg
2010-08-10 2:23 ` Jens Axboe
2010-08-10 2:23 ` Jens Axboe
2010-08-10 2:23 ` Jens Axboe
2010-08-10 4:54 ` Nitin Gupta
2010-08-10 4:54 ` Nitin Gupta
2010-08-10 4:54 ` Nitin Gupta
2010-08-10 15:54 ` Jens Axboe
2010-08-10 15:54 ` Jens Axboe
2010-08-10 15:54 ` Jens Axboe
2010-08-09 17:26 ` [PATCH 07/10] Increase compressed page size threshold Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 18:32 ` Pekka Enberg
2010-08-09 18:32 ` Pekka Enberg
2010-08-09 17:26 ` [PATCH 08/10] Some cleanups Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 19:02 ` Pekka Enberg
2010-08-09 19:02 ` Pekka Enberg
2010-08-09 17:26 ` [PATCH 09/10] Update zram documentation Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 17:26 ` [PATCH 10/10] Document sysfs entries Nitin Gupta
2010-08-09 17:26 ` Nitin Gupta
2010-08-09 19:02 ` Pekka Enberg
2010-08-09 19:02 ` Pekka Enberg
2010-08-31 22:37 ` [PATCH 00/10] zram: various improvements and cleanups Greg KH
2010-08-31 22:37 ` Greg KH
2010-09-01 3:32 ` Anton Blanchard
2010-09-01 3:32 ` Anton Blanchard
2010-09-09 17:24 ` OOM panics with zram Dave Hansen
2010-09-09 17:24 ` Dave Hansen
2010-09-09 19:07 ` [patch -rc] oom: always return a badness score of non-zero for eligible tasks David Rientjes
2010-09-09 19:07 ` David Rientjes
2010-09-09 19:48 ` Dave Hansen
2010-09-09 19:48 ` Dave Hansen
2010-09-09 21:00 ` David Rientjes
2010-09-09 21:00 ` David Rientjes
2010-09-09 21:10 ` Dave Hansen
2010-09-09 21:10 ` Dave Hansen
2010-09-09 21:40 ` David Rientjes
2010-09-09 21:40 ` David Rientjes
2010-10-03 18:41 ` OOM panics with zram Nitin Gupta
2010-10-03 18:41 ` Nitin Gupta
2010-10-03 19:27 ` Dave Hansen
2010-10-03 19:27 ` Dave Hansen
2010-10-03 19:40 ` Nitin Gupta
2010-10-03 19:40 ` Nitin Gupta
2010-10-04 11:08 ` Ed Tomlinson
2010-10-04 11:08 ` Ed Tomlinson
2010-10-05 23:43 ` Greg KH
2010-10-05 23:43 ` Greg KH
2010-10-06 2:29 ` Nitin Gupta
2010-10-06 2:29 ` Nitin Gupta
2010-10-06 2:36 ` Greg KH
2010-10-06 2:36 ` Greg KH
2010-10-06 4:30 ` Nitin Gupta
2010-10-06 4:30 ` Nitin Gupta
2010-10-06 7:38 ` Pekka Enberg
2010-10-06 7:38 ` Pekka Enberg
2010-10-06 14:03 ` Greg KH
2010-10-06 14:03 ` Greg KH
2010-10-06 14:16 ` Pekka Enberg
2010-10-06 14:16 ` Pekka Enberg
2010-10-06 14:53 ` Nitin Gupta
2010-10-06 14:53 ` Nitin Gupta
2010-10-06 14:02 ` Greg KH
2010-10-06 14:02 ` Greg KH
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=1283373495.2484.41.camel@edumazet-laptop \
--to=eric.dumazet@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=cl@linux.com \
--cc=devel@driverdev.osuosl.org \
--cc=greg@kroah.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=minchan.kim@gmail.com \
--cc=ngupta@vflare.org \
--cc=penberg@cs.helsinki.fi \
/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.