Re: [PATCH 3/3] blktrace: fix the original blktrace

[Li Zefan <lizf@cn.fujitsu.com>]

Jens Axboe wrote:
> On Wed, Mar 25 2009, Ingo Molnar wrote:
>> * Li Zefan <lizf@cn.fujitsu.com> wrote:
>>
>>> Currently the original blktrace, which is using relay and is used 
>>> via ioctl, is broken. You can use ftrace to see the output of 
>>> blktrace, but user-space blktrace is unusable.
>> good catch, thanks Li!
>>
>> Jens, Arnaldo, do these fixes look good to you too?
> 
> Look fine, but I'm very worried about the state of the current code. I
> mean, this last round of fixes got the timestamp correct and made
> blktrace work again. Those are something that should have been caught
> even before the whole thing was posted, let alone merged. When do you
> plan on pushing this upstream? Looks like 2.6.31 to me, it's clearly not
> ready for 2.6.30 by any stretch.
> 

Actually not all the bugs I found are introduced by "blktrace: ftrace plugin"
in -tip tree.

One is introduced by "block: get rid of the manual directory counting in blktrace"
(f48fc4d32e24c0b6a18aad30305d819bcc68c049). Two are "blktrace: port to tracepoints"
(5f3ea37c7716db4e894a480e0c18b24399595b6b). Both commits are in mainline.

Since 2 of the bugs will rarely happen in real-life, and the 3rd one is a small
issue, and we were so close to the release of .29, so I sent the fixes for -tip
tree but not mainline. But if we are going merge tip/blktrace to .31, I guess
it's better to merge that 3 fixes to .30?