From: Dan Carpenter <dan.carpenter@oracle.com>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
devel@driverdev.osuosl.org, Minchan Kim <minchan@kernel.org>,
Jerome Marchand <jmarchan@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] staging: zram: minimize `slot_free_lock' usage (v2)
Date: Mon, 9 Sep 2013 15:33:29 +0300 [thread overview]
Message-ID: <20130909123329.GZ19256@mwanda> (raw)
In-Reply-To: <20130906151255.GE2238@swordfish.minsk.epam.com>
On Fri, Sep 06, 2013 at 06:12:55PM +0300, Sergey Senozhatsky wrote:
> Calling handle_pending_slot_free() for every RW operation may
> cause unneccessary slot_free_lock locking, because most likely
> process will see NULL slot_free_rq. handle_pending_slot_free()
> only when current detects that slot_free_rq is not NULL.
>
> v2: protect handle_pending_slot_free() with zram rw_lock.
>
zram->slot_free_lock protects zram->slot_free_rq but shouldn't the zram
rw_lock be wrapped around the whole operation like the original code
does? I don't know the zram code, but the original looks like it makes
sense but in this one it looks like the locks are duplicative.
Is the down_read() in the original code be changed to down_write()?
regards,
dan carpenter
next prev parent reply other threads:[~2013-09-09 12:33 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-06 15:12 [PATCH 1/2] staging: zram: minimize `slot_free_lock' usage (v2) Sergey Senozhatsky
2013-09-09 12:33 ` Dan Carpenter [this message]
2013-09-09 12:49 ` Sergey Senozhatsky
2013-09-09 13:21 ` Dan Carpenter
2013-09-09 13:46 ` Jerome Marchand
2013-09-09 16:10 ` Jerome Marchand
2013-09-10 14:34 ` Sergey Senozhatsky
2013-09-10 14:58 ` Dan Carpenter
2013-09-10 15:15 ` Greg Kroah-Hartman
2013-09-10 23:12 ` [PATCH 1/2] staging: zram: fix handle_pending_slot_free() and zram_reset_device() race Sergey Senozhatsky
2013-09-12 22:12 ` Greg KH
2013-09-13 9:17 ` Sergey Senozhatsky
2013-09-16 0:02 ` Minchan Kim
2013-09-17 17:24 ` Sergey Senozhatsky
2013-09-23 4:24 ` Minchan Kim
2013-09-23 8:42 ` Sergey Senozhatsky
2013-09-10 23:19 ` [PATCH 2/2] staging: zram: remove init_done from zram struct (v3) Sergey Senozhatsky
2013-09-10 23:27 ` [PATCH 1/2] staging: zram: minimize `slot_free_lock' usage (v2) Sergey Senozhatsky
2013-09-09 14:42 ` Sergey Senozhatsky
2013-09-09 14:52 ` Dan Carpenter
2013-09-09 15:09 ` Sergey Senozhatsky
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