From: Bob Liu <bob.liu@oracle.com>
To: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Mel Gorman <mgorman@suse.de>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Kyungmin Park <kyungmin.park@samsung.com>,
Dave Hansen <dave.hansen@intel.com>,
Minchan Kim <minchan@kernel.org>
Subject: Re: [PATCH v2 0/5] mm: migrate zbud pages
Date: Tue, 17 Sep 2013 14:59:24 +0800 [thread overview]
Message-ID: <5237FDCC.5010109@oracle.com> (raw)
In-Reply-To: <1378889944-23192-1-git-send-email-k.kozlowski@samsung.com>
Hi Krzysztof,
On 09/11/2013 04:58 PM, Krzysztof Kozlowski wrote:
> Hi,
>
> Currently zbud pages are not movable and they cannot be allocated from CMA
> (Contiguous Memory Allocator) region. These patches add migration of zbud pages.
>
I agree that the migration of zbud pages is important so that system
will not enter order-0 page fragmentation and can be helpful for page
compaction/huge pages etc..
But after I looked at the [patch 4/5], I found it will make zbud very
complicated.
I'd prefer to add this migration feature later until current version
zswap/zbud becomes better enough and more stable.
Mel mentioned several problems about zswap/zbud in thread "[PATCH v6
0/5] zram/zsmalloc promotion".
Like "it's clunky as hell and the layering between zswap and zbud is
twisty" and "I think I brought up its stalling behaviour during review
when it was being merged. It would have been preferable if writeback
could be initiated in batches and then waited on at the very least..
It's worse that it uses _swap_writepage directly instead of going
through a writepage ops. It would have been better if zbud pages
existed on the LRU and written back with an address space ops and
properly handled asynchonous writeback."
So I think it would be better if we can address those issues at first
and it would be easier to address these issues before adding more new
features. Welcome any ideas.
--
Regards,
-Bob
--
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:[~2013-09-17 6:59 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-11 8:58 [PATCH v2 0/5] mm: migrate zbud pages Krzysztof Kozlowski
2013-09-11 8:59 ` [PATCH v2 1/5] zbud: use page ref counter for " Krzysztof Kozlowski
2013-09-11 8:59 ` [PATCH v2 2/5] zbud: make freechunks a block local variable Krzysztof Kozlowski
2013-09-11 8:59 ` [PATCH v2 3/5] mm: use mapcount for identifying zbud pages Krzysztof Kozlowski
2013-09-11 8:59 ` [PATCH v2 4/5] mm: use indirect zbud handle and radix tree Krzysztof Kozlowski
2013-09-11 8:59 ` [PATCH v2 5/5] mm: migrate zbud pages Krzysztof Kozlowski
2013-09-17 6:59 ` Bob Liu [this message]
2013-09-23 17:19 ` [PATCH v2 0/5] " Seth Jennings
2013-09-23 22:07 ` Seth Jennings
2013-09-24 9:20 ` Krzysztof Kozlowski
2013-09-25 4:28 ` Bob Liu
2013-09-25 17:09 ` Tomasz Stanislawski
2013-09-25 21:57 ` Seth Jennings
2013-09-27 10:16 ` Tomasz Stanislawski
2013-09-27 22:00 ` Seth Jennings
2013-09-28 2:43 ` Bob Liu
2013-09-30 8:28 ` Krzysztof Kozlowski
2013-10-01 21:04 ` Seth Jennings
2013-10-03 13:24 ` Krzysztof Kozlowski
2013-10-03 15:39 ` Seth Jennings
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=5237FDCC.5010109@oracle.com \
--to=bob.liu@oracle.com \
--cc=akpm@linux-foundation.org \
--cc=b.zolnierkie@samsung.com \
--cc=dave.hansen@intel.com \
--cc=k.kozlowski@samsung.com \
--cc=kyungmin.park@samsung.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=m.szyprowski@samsung.com \
--cc=mgorman@suse.de \
--cc=minchan@kernel.org \
--cc=sjenning@linux.vnet.ibm.com \
/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).