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Date:   Thu, 8 Sep 2022 11:41:53 +0530
From:   "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
To:     Alexey Lyahkov <alexey.lyashkov@gmail.com>
Cc:     linux-ext4 <linux-ext4@vger.kernel.org>,
        Theodore Ts'o <tytso@mit.edu>,
        Andreas Dilger <adilger@dilger.ca>,
        Artem Blagodarenko <artem.blagodarenko@gmail.com>,
        Andrew Perepechko <anserper@ya.ru>
Subject: Re: [PATCH] jbd2: wake up journal waiters in FIFO order, not  LIFO
Message-ID: <20220908061153.dflgx7fjjav7pxyn@riteshh-domain>
References: <20220907165959.1137482-1-alexey.lyashkov@gmail.com>
 <20220908054611.vjcb27wmq4dggqmv@riteshh-domain>
 <B32B956C-E851-42A2-9419-2947C442E2AA@gmail.com>
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On 22/09/08 08:51AM, Alexey Lyahkov wrote:
> Hi Ritesh,
> 
> This was hit on the Lustre OSS node when we have ton’s of short write with sync/(journal commit) in parallel.
> Each write was done from own thread (like 1k-2k threads in parallel).
> It caused a situation when only few/some threads make a wakeup and enter to the transaction until it will be T_LOCKED.
> In our’s observation all handles from head was waked and it’s handles added recently, while old handles still in list and

Thanks Alexey for providing the details.

> It caused a soft lockup messages on console.

Did you mean hung task timeout? I was wondering why will there be soft lockup
warning, because these old handles are anyway in a waiting state right.
Am I missing something?

-ritesh