From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Mikael Pettersson <mikpelinux@gmail.com>
Cc: Linux SPARC Kernel Mailing List <sparclinux@vger.kernel.org>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500
Date: Sun, 10 Feb 2019 07:44:32 -0800 [thread overview]
Message-ID: <1549813472.4142.3.camel@HansenPartnership.com> (raw)
In-Reply-To: <CAM43=SPUMzOLRmkoT+DQSpzu2DYRTyOhU6o8KRUU_Q902o2e1Q@mail.gmail.com>
On Sun, 2019-02-10 at 10:17 +0100, Mikael Pettersson wrote:
> On Sat, Feb 9, 2019 at 7:19 PM James Bottomley
> <James.Bottomley@hansenpartnership.com> wrote:
[...]
> > I think the reason for this is that the block mq path doesn't feed
> > the kernel entropy pool correctly, hence the need to install an
> > entropy gatherer for systems that don't have other good random
> > number sources.
>
> That does sound plausible, I admit I didn't even consider the
> possibility that the old block I/O path also was an entropy source.
In theory, the new one should be as well since the rotational entropy
collector is on the SCSI completion path. I'd seen the same problem
but had assumed it was something someone had done to our internal
entropy pool and thus hadn't bisected it.
James
WARNING: multiple messages have this Message-ID (diff)
From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Mikael Pettersson <mikpelinux@gmail.com>
Cc: Linux SPARC Kernel Mailing List <sparclinux@vger.kernel.org>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su
Date: Sun, 10 Feb 2019 15:44:32 +0000 [thread overview]
Message-ID: <1549813472.4142.3.camel@HansenPartnership.com> (raw)
In-Reply-To: <CAM43=SPUMzOLRmkoT+DQSpzu2DYRTyOhU6o8KRUU_Q902o2e1Q@mail.gmail.com>
On Sun, 2019-02-10 at 10:17 +0100, Mikael Pettersson wrote:
> On Sat, Feb 9, 2019 at 7:19 PM James Bottomley
> <James.Bottomley@hansenpartnership.com> wrote:
[...]
> > I think the reason for this is that the block mq path doesn't feed
> > the kernel entropy pool correctly, hence the need to install an
> > entropy gatherer for systems that don't have other good random
> > number sources.
>
> That does sound plausible, I admit I didn't even consider the
> possibility that the old block I/O path also was an entropy source.
In theory, the new one should be as well since the rotational entropy
collector is on the SCSI completion path. I'd seen the same problem
but had assumed it was something someone had done to our internal
entropy pool and thus hadn't bisected it.
James
next prev parent reply other threads:[~2019-02-10 15:44 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-09 17:04 [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Mikael Pettersson
2019-02-09 17:04 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Bl Mikael Pettersson
2019-02-09 18:19 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 James Bottomley
2019-02-09 18:19 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su James Bottomley
2019-02-10 9:17 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Mikael Pettersson
2019-02-10 9:17 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su Mikael Pettersson
2019-02-10 15:44 ` James Bottomley [this message]
2019-02-10 15:44 ` James Bottomley
2019-02-10 16:05 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Jens Axboe
2019-02-10 16:05 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su Jens Axboe
2019-02-10 16:25 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 James Bottomley
2019-02-10 16:25 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su James Bottomley
2019-02-10 16:35 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Jens Axboe
2019-02-10 16:35 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su Jens Axboe
2019-02-11 15:25 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 James Bottomley
2019-02-11 15:25 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su James Bottomley
2019-02-11 15:28 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Jens Axboe
2019-02-11 15:28 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su Jens Axboe
2019-02-11 15:42 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 James Bottomley
2019-02-11 15:42 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su James Bottomley
2019-02-11 15:46 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Jens Axboe
2019-02-11 15:46 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su Jens Axboe
2019-02-11 16:28 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 James Bottomley
2019-02-11 16:28 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su James Bottomley
2019-02-11 16:31 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Jens Axboe
2019-02-11 16:31 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su Jens Axboe
2019-02-12 2:13 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 James Bottomley
2019-02-12 2:13 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su James Bottomley
2019-02-12 2:50 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Jens Axboe
2019-02-12 2:50 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su Jens Axboe
2019-02-12 3:37 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Elliott, Robert (Persistent Memory)
2019-02-12 3:37 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su Elliott, Robert (Persistent Memory)
2019-02-12 4:15 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 James Bottomley
2019-02-12 4:15 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su James Bottomley
2019-02-12 15:24 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 James Bottomley
2019-02-12 15:24 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su James Bottomley
2019-02-12 15:27 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Jens Axboe
2019-02-12 15:27 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su Jens Axboe
2019-02-14 18:35 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Sun Blade 2500 Mikael Pettersson
2019-02-14 18:35 ` [5.0-rc5 regression] "scsi: kill off the legacy IO path" causes 5 minute delay during boot on Su Mikael Pettersson
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