Message-ID: <1501391551.17388.31.camel@gmx.de>
Subject: Re: blk-mq breaks suspend even with runtime PM patch
From: Mike Galbraith <efault@gmx.de>
To: Oleksandr Natalenko <oleksandr@natalenko.name>,
        Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org
Date: Sun, 30 Jul 2017 07:12:31 +0200
In-Reply-To: <5912148.iRCpNe8Dyb@natalenko.name>
References: <5912148.iRCpNe8Dyb@natalenko.name>
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On Sat, 2017-07-29 at 17:27 +0200, Oleksandr Natalenko wrote:
> Hello Jens, Christoph.
> 
> Unfortunately, even with "block: disable runtime-pm for blk-mq" patch applied 
> blk-mq breaks suspend to RAM for me. It is reproducible on my laptop as well 
> as in a VM.
> 
> I use complex disk layout involving MD, LUKS and LVM, and managed to get these 
> warnings from VM via serial console when suspend fails:
> 
> ===
> [  245.516573] INFO: task kworker/0:1:49 blocked for more than 120 seconds.
> [  245.520025]       Not tainted 4.12.0-pf4 #1

FWIW, first thing I'd do is update that 4.12.0 to 4.12.4, and see if
stable fixed it.  If not, I'd find these two commits irresistible.

5f042e7cbd9eb blk-mq: Include all present CPUs in the default queue mapping
4b855ad37194f blk-mq: Create hctx for each present CPU

'course applying random upstream bits does come with some risk, trying
a kernel already containing them has less "entertainment" potential. 

	-Mike