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Date:   Sun, 11 Sep 2022 14:32:45 +0200
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Subject: Re: [PATCH 0/5 v3] ext4: Fix performance regression with mballoc
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To:     Jan Kara <jack@suse.cz>
Cc:     linux-ext4@vger.kernel.org,
        Thorsten Leemhuis <regressions@leemhuis.info>,
        Ojaswin Mujoo <ojaswin@linux.ibm.com>,
        Harshad Shirwadkar <harshadshirwadkar@gmail.com>,
        Ted Tso <tytso@mit.edu>
References: <20220908091301.147-1-jack@suse.cz>
 <4826b1af-1264-3b3a-e71c-38937c75641c@i2se.com>
 <20220909104014.xgzdlzem3f7mbccd@quack3>
From:   Stefan Wahren <stefan.wahren@i2se.com>
In-Reply-To: <20220909104014.xgzdlzem3f7mbccd@quack3>
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Hi Jan,

Am 09.09.22 um 12:40 schrieb Jan Kara:
> On Thu 08-09-22 12:36:10, Stefan Wahren wrote:
>> Hi Jan,
>>
>> Am 08.09.22 um 11:21 schrieb Jan Kara:
>>> Hello,
>>>
>>> Here is the third version of my mballoc improvements to avoid spreading
>>> allocations with mb_optimize_scan=1. Since v2 there are only small changes and
>>> fixes found during review and testing. Overall the series looks mostly ready to
>>> go, I just didn't see any comments regarding patch 3 - a fix of metabg handling
>>> in the Orlov allocator which is kind of independent, I've just found it when
>>> reading the code. Also patch 5 needs final review after all the fixes.
>>>
>>> Changes since v1:
>>> - reworked data structure for CR 1 scan
>>> - make small closed files use locality group preallocation
>>> - fix metabg handling in the Orlov allocator
>>>
>>> Changes since v2:
>>> - whitespace fixes
>>> - fix outdated comment
>>> - fix handling of mb_structs_summary procfs file
>>> - fix bad unlock on error recovery path
>> unfortunately the real patches doesn't have v3 which leads to confusion.
> Yeah, OK, I've updated my scripting for posting patches to include version
> in each posted patch :)
>
>> Just a note: in case this series cannot be applied for stable (5.15), we
>> need a second solution to fix the regression there.
> My plan is to backport the current series. It is not that invasive so it
> should be doable...

This would be great.

Btw i retested this version and i can confirm the procfs crash is fixed.

>
> 								Honza