From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Henry Burns <henryburns@google.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Minchan Kim <minchan@kernel.org>, Nitin Gupta <ngupta@vflare.org>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Shakeel Butt <shakeelb@google.com>,
Jonathan Adams <jwadams@google.com>,
HenryBurns <henrywolfeburns@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2 v2] mm/zsmalloc.c: Migration can leave pages in ZS_EMPTY indefinitely
Date: Tue, 20 Aug 2019 11:53:07 +0900 [thread overview]
Message-ID: <20190820025307.GC500@jagdpanzerIV> (raw)
In-Reply-To: <20190809181751.219326-1-henryburns@google.com>
On (08/09/19 11:17), Henry Burns wrote:
> In zs_page_migrate() we call putback_zspage() after we have finished
> migrating all pages in this zspage. However, the return value is ignored.
> If a zs_free() races in between zs_page_isolate() and zs_page_migrate(),
> freeing the last object in the zspage, putback_zspage() will leave the page
> in ZS_EMPTY for potentially an unbounded amount of time.
>
> To fix this, we need to do the same thing as zs_page_putback() does:
> schedule free_work to occur. To avoid duplicated code, move the
> sequence to a new putback_zspage_deferred() function which both
> zs_page_migrate() and zs_page_putback() call.
>
> Fixes: 48b4800a1c6a ("zsmalloc: page migration support")
> Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
+ Andrew
-ss
prev parent reply other threads:[~2019-08-20 2:53 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-09 18:17 [PATCH 1/2 v2] mm/zsmalloc.c: Migration can leave pages in ZS_EMPTY indefinitely Henry Burns
2019-08-09 18:17 ` [PATCH 2/2 v2] mm/zsmalloc.c: Fix race condition in zs_destroy_pool Henry Burns
2019-08-20 2:59 ` Sergey Senozhatsky
2019-08-22 23:23 ` Andrew Morton
2019-08-23 8:10 ` Henry Burns
2019-08-26 5:13 ` Sergey Senozhatsky
2019-08-20 2:53 ` Sergey Senozhatsky [this message]
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=20190820025307.GC500@jagdpanzerIV \
--to=sergey.senozhatsky.work@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=henryburns@google.com \
--cc=henrywolfeburns@gmail.com \
--cc=jwadams@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=minchan@kernel.org \
--cc=ngupta@vflare.org \
--cc=shakeelb@google.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 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.