From: Dave Hansen <dave@linux.vnet.ibm.com> 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>, Greg KH - Meetings <ghartman@us.ibm.com> Subject: Re: OOM panics with zram Date: Sun, 03 Oct 2010 12:27:53 -0700 [thread overview] Message-ID: <1286134073.9970.11.camel@nimitz> (raw) In-Reply-To: <4CA8CE45.9040207@vflare.org> On Sun, 2010-10-03 at 14:41 -0400, Nitin Gupta wrote: > Ability to write out zram (compressed) memory to a backing disk seems > really useful. However considering lkml reviews, I had to drop this > feature. Anyways, I guess I will try to push this feature again. I'd argue that zram is pretty useless without some ability to write to a backing store, unless you *really* know what is going to be stored in it and you trust the user. Otherwise, it's just too easy to OOM the system. I've been investigating backing the xvmalloc space with a tmpfs file. Instead of keeping page/offset pairs, you just keep a linear address inside the tmpfile file. There's an extra step needed to look up and lock the page cache page into place each time you go into the xvmalloc store, but it does seem to basically work. The patches are really rough and not quite functional, but I'm happy to share if you want to see them now. > Also, please do not use linux-next/mainline version of compcache. Instead > just use version in the project repository here: > hg clone https://compcache.googlecode.com/hg/ compcache > > This is updated much more frequently and has many more bug fixes over > the mainline. It will also be easier to fix bugs/add features much more > quickly in this repo rather than sending them to lkml which can take > long time. That looks like just a clone of the code needed to build the module. Kernel developers are pretty used to _some_ kernel tree being the authoritative source. Also, having it in a kernel tree makes it possible to get testing in places like linux-next, and it makes it easier for people to make patches or kernel trees on top of your work. There's not really a point to the code being in -staging if it isn't somewhat up-to-date or people can't generate patches to it. It sounds to me like we need to take it out of -staging. -- Dave
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From: Dave Hansen <dave@linux.vnet.ibm.com> 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>, Greg KH - Meetings <ghartman@us.ibm.com> Subject: Re: OOM panics with zram Date: Sun, 03 Oct 2010 12:27:53 -0700 [thread overview] Message-ID: <1286134073.9970.11.camel@nimitz> (raw) In-Reply-To: <4CA8CE45.9040207@vflare.org> On Sun, 2010-10-03 at 14:41 -0400, Nitin Gupta wrote: > Ability to write out zram (compressed) memory to a backing disk seems > really useful. However considering lkml reviews, I had to drop this > feature. Anyways, I guess I will try to push this feature again. I'd argue that zram is pretty useless without some ability to write to a backing store, unless you *really* know what is going to be stored in it and you trust the user. Otherwise, it's just too easy to OOM the system. I've been investigating backing the xvmalloc space with a tmpfs file. Instead of keeping page/offset pairs, you just keep a linear address inside the tmpfile file. There's an extra step needed to look up and lock the page cache page into place each time you go into the xvmalloc store, but it does seem to basically work. The patches are really rough and not quite functional, but I'm happy to share if you want to see them now. > Also, please do not use linux-next/mainline version of compcache. Instead > just use version in the project repository here: > hg clone https://compcache.googlecode.com/hg/ compcache > > This is updated much more frequently and has many more bug fixes over > the mainline. It will also be easier to fix bugs/add features much more > quickly in this repo rather than sending them to lkml which can take > long time. That looks like just a clone of the code needed to build the module. Kernel developers are pretty used to _some_ kernel tree being the authoritative source. Also, having it in a kernel tree makes it possible to get testing in places like linux-next, and it makes it easier for people to make patches or kernel trees on top of your work. There's not really a point to the code being in -staging if it isn't somewhat up-to-date or people can't generate patches to it. It sounds to me like we need to take it out of -staging. -- Dave -- 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:[~2010-10-03 19:28 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 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 [this message] 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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