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From: Jens Axboe <>
Subject: [PATCHSET 0/5] io-wq fixes
Date: Thu,  2 Sep 2021 13:25:15 -0600	[thread overview]
Message-ID: <> (raw)


Got a report on io-wq stalls, and it turned into quite the rabbit hole
of fixes. There are two main things fixed by this series:

1) Single ring that has a lot of bounded vs unbounded traffic. The fix
   is mainly just splitting the bounded and unbounded lists, so that we
   never stall bounded unnecessarily. There are further cleanups possible
   on top of this, but that should be deferred to 5.16.

2) Workloads that have io-wq work and rely heavily on signaling to
   communicate between processes/threads. This can interfere with worker
   creation, and this is particularly troublesome if it just happens to
   occur with the first worker creation.

In general, harden the worker creation and ensure we handle failures in
terms of allocations and worker creations.

Jens Axboe

             reply	other threads:[~2021-09-02 19:25 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-02 19:25 Jens Axboe [this message]
2021-09-02 19:25 ` [PATCH 1/5] io-wq: fix queue stalling race Jens Axboe
2021-09-02 19:25 ` [PATCH 2/5] io-wq: split bounded and unbounded work into separate lists Jens Axboe
2021-09-02 19:25 ` [PATCH 3/5] io-wq: only exit on fatal signals Jens Axboe
2021-09-02 19:25 ` [PATCH 4/5] io-wq: get rid of FIXED worker flag Jens Axboe
2021-09-02 19:25 ` [PATCH 5/5] io-wq: make worker creation resilient against signals Jens Axboe

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