From: Pekka Enberg <penberg@kernel.org>
To: Nitin Gupta <ngupta@vflare.org>
Cc: 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 07/10] Increase compressed page size threshold
Date: Mon, 9 Aug 2010 21:32:11 +0300 [thread overview]
Message-ID: <AANLkTikwN08QsfRNwa-4=qOu8mKkGoEUHdxUC5n8u3Ve@mail.gmail.com> (raw)
In-Reply-To: <1281374816-904-8-git-send-email-ngupta@vflare.org>
Hi Nitin,
On Mon, Aug 9, 2010 at 8:26 PM, Nitin Gupta <ngupta@vflare.org> wrote:
> Compression takes much more time than decompression. So, its quite
> wasteful in terms of both CPU cycles and memory usage to have a very
> low compressed page size threshold and thereby storing such not-so-well
> compressible pages as-is (uncompressed). So, increasing it from
> PAGE_SIZE/2 to PAGE_SIZE/8*7. A low threshold was useful when we had
> "backing swap" support where we could forward such pages to the backing
> device (applicable only when zram was used as swap disk).
>
> It is not yet configurable through sysfs but may be exported in future,
> along with threshold for average compression ratio.
>
> Signed-off-by: Nitin Gupta <ngupta@vflare.org>
The description makes sense but lacks any real data. What kind of
workloads did you test this with? Where does it help most? How much?
Pekka
WARNING: multiple messages have this Message-ID (diff)
From: Pekka Enberg <penberg@kernel.org>
To: Nitin Gupta <ngupta@vflare.org>
Cc: 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@linuxdriverproject.org>,
linux-mm <linux-mm@kvack.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 07/10] Increase compressed page size threshold
Date: Mon, 9 Aug 2010 21:32:11 +0300 [thread overview]
Message-ID: <AANLkTikwN08QsfRNwa-4=qOu8mKkGoEUHdxUC5n8u3Ve@mail.gmail.com> (raw)
In-Reply-To: <1281374816-904-8-git-send-email-ngupta@vflare.org>
Hi Nitin,
On Mon, Aug 9, 2010 at 8:26 PM, Nitin Gupta <ngupta@vflare.org> wrote:
> Compression takes much more time than decompression. So, its quite
> wasteful in terms of both CPU cycles and memory usage to have a very
> low compressed page size threshold and thereby storing such not-so-well
> compressible pages as-is (uncompressed). So, increasing it from
> PAGE_SIZE/2 to PAGE_SIZE/8*7. A low threshold was useful when we had
> "backing swap" support where we could forward such pages to the backing
> device (applicable only when zram was used as swap disk).
>
> It is not yet configurable through sysfs but may be exported in future,
> along with threshold for average compression ratio.
>
> Signed-off-by: Nitin Gupta <ngupta@vflare.org>
The description makes sense but lacks any real data. What kind of
workloads did you test this with? Where does it help most? How much?
Pekka
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next prev parent reply other threads:[~2010-08-09 18:32 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
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 [this message]
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
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