From: Theodore Ts'o <tytso@mit.edu>
To: Jan Kara <jack@suse.cz>
Cc: linux-ext4@vger.kernel.org, Yuanhan Liu <yuanhan.liu@linux.intel.com>
Subject: Re: [PATCH 1/2] jbd2: Avoid pointless scanning of checkpoint lists
Date: Thu, 18 Sep 2014 00:47:44 -0400 [thread overview]
Message-ID: <20140918044744.GE24887@thunk.org> (raw)
In-Reply-To: <1410946290-5128-1-git-send-email-jack@suse.cz>
On Wed, Sep 17, 2014 at 11:31:29AM +0200, Jan Kara wrote:
> Yuanhan has reported that when he is running fsync(2) heavy workload
> creating new files over ramdisk, significant amount of time is spent in
> __jbd2_journal_clean_checkpoint_list() trying to clean old transactions
> (but they cannot be cleaned up because flusher hasn't yet checkpointed
> those buffers). The workload can be generated by:
> fs_mark -d /fs/ram0/1 -D 2 -N 2560 -n 1000000 -L 1 -S 1 -s 4096
>
> Reduce the amount of scanning by stopping to scan the transaction list
> once we find a transaction that cannot be checkpointed. Note that this
> way of cleaning is still enough to keep freeing space in the journal
> after fully checkpointed transactions.
>
> Reported-and-tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> Signed-off-by: Jan Kara <jack@suse.cz>
Applied, thanks.
- Ted
next prev parent reply other threads:[~2014-09-18 4:47 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-17 9:31 [PATCH 1/2] jbd2: Avoid pointless scanning of checkpoint lists Jan Kara
2014-09-17 9:31 ` [PATCH 2/2] jbd2: Simplify calling convention around __jbd2_journal_clean_checkpoint_list Jan Kara
2014-09-18 5:02 ` Theodore Ts'o
2014-09-18 4:47 ` Theodore Ts'o [this message]
-- strict thread matches above, loose matches on Subject: below --
2014-10-10 14:23 [Cluster-devel] [PATCH 0/2 v2] Fix data corruption when blocksize < pagesize for mmapped data Jan Kara
2014-10-10 14:23 ` [PATCH 1/2] jbd2: Avoid pointless scanning of checkpoint lists Jan Kara
2014-10-10 14:23 ` Jan Kara
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