From: Jens Axboe <axboe@kernel.dk>
To: Thomas Fjellstrom <thomas@fjellstrom.ca>
Cc: linux-block@vger.kernel.org
Subject: Re: recent issues with heavy delete's causing soft lockups
Date: Fri, 2 Nov 2018 14:37:08 -0600 [thread overview]
Message-ID: <baa9f4e4-34e2-1112-5d01-ce86c1b51005@kernel.dk> (raw)
In-Reply-To: <5281881.2vk5iP2XJf@natasha>
On 11/2/18 2:32 PM, Thomas Fjellstrom wrote:
> On Saturday, October 27, 2018 1:20:10 PM MDT Jens Axboe wrote:
>> On Oct 27, 2018, at 12:40 PM, Thomas Fjellstrom <thomas@fjellstrom.ca>
> [snip]
>>
>> Can you try 4.19? A patch went in since 4.18 that fixes a starvation issue
>> around requeue conditions, which SATA is the one to most often hit.
>>
>> Jens
>
> I just had to do a clean, and I have the mq kernel options I mentioned in my
> previous mail enabled. (mq should be disabled) and it appears to still be
> causing issues. current io scheduler appears to be cfq, and it took that "make
> clean" about 4 minutes, a lot of that time was spent with plasma, intelij, and
> chrome all starved of IO.
>
> I did switch to a terminal and checked iostat -d 1, and it showed very little
> actual io for the time I was looking at it.
>
> I have no idea what's going on.
If you're using cfq, then it's not using mq at all. Maybe do something ala:
# perf record -ag -- sleep 10
while the slowdown is happening and then do perf report -g --no-children and
see if that yields anything interesting. Sounds like time is being spent
elsewhere and you aren't actually waiting on IO.
--
Jens Axboe
next prev parent reply other threads:[~2018-11-02 20:37 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-27 18:40 recent issues with heavy delete's causing soft lockups Thomas Fjellstrom
2018-10-27 19:20 ` Jens Axboe
2018-11-02 18:25 ` Thomas Fjellstrom
2018-11-02 20:32 ` Thomas Fjellstrom
2018-11-02 20:37 ` Jens Axboe [this message]
2018-11-21 21:25 ` Thomas Fjellstrom
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