Re: [Bug #13726] fio sync read 4k block size 35% regression

Zhang, Yanmin
2009-07-07T06:06:42Z

On Tue, 2009-07-07 at 02:01 +0200, Rafael J. Wysocki wrote:
> This message has been generated automatically as a part of a report
> of recent regressions.
>
> The following bug entry is on the current list of known regressions
> from 2.6.30. Please verify if it still should be listed and let me know
> (either way).
>
>
> Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=13726
> Subject : fio sync read 4k block size 35% regression
> Submitter : Zhang, Yanmin <yanmin_zhang-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Date : 2009-07-01 11:25 (6 days old)
> First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=51daa88ebd8e0d437289f589af29d4b39379ea76
> References : http://lkml.org/lkml/2009/6/30/679
> Handled-By : Wu Fengguang <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Fengguang,

I'm still working on it now. The new testing against 2.6.31-rc2 is ongoing.
fio sync/mmap read has new behavior. I did collect some data. But suddenly
with new created data, the fio_sync_read_4k regression disappeared, while
fio_mmap_read is still there. Originally, the testing and bisect were stable.
Let me check what happens firstly.

Just update.
ï»¿
How did you test your new readahead patches before sending to LKML?

Yanmin