linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Bjorn Helgaas <helgaas@kernel.org>
To: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
Cc: Logan Gunthorpe <logang@deltatee.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>
Subject: Re: Possible PCI Regression Linux 5.3-rc1
Date: Wed, 24 Jul 2019 08:38:14 -0500	[thread overview]
Message-ID: <20190724133814.GA194025@google.com> (raw)
In-Reply-To: <SL2P216MB01878BBCD75F21D882AEEA2880C60@SL2P216MB0187.KORP216.PROD.OUTLOOK.COM>

On Wed, Jul 24, 2019 at 12:54:00PM +0000, Nicholas Johnson wrote:
> Hi all,
> 
> I was just rebasing my patches for linux 5.3-rc1 and noticed a possible 
> regression that shows on both of my machines. It is also reproducible 
> with the unmodified Ubuntu mainline kernel, downloadable at [1].
> 
> Running the lspci command takes 1-3 seconds with 5.3-rc1 (rather than an 
> imperceivable amount of time). Booting with pci.dyndbg does not reveal 
> why.
> 
> $ uname -r
> 5.3.0-050300rc1-generic
> $ time lspci -vt 1>/dev/null
> 
> real	0m2.321s
> user	0m0.026s
> sys	0m0.000s
> 
> If none of you are aware of this or what is causing it, I will submit a 
> bug report to Bugzilla.

I wasn't aware of this; thanks for reporting it!  I wasn't able to
reproduce this in qemu.  Can you play with "strace -r lspci -vt" and
the like?  Maybe try "lspci -n" to see if it's related to looking up
the names?

  reply	other threads:[~2019-07-24 13:38 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-24 12:54 Possible PCI Regression Linux 5.3-rc1 Nicholas Johnson
2019-07-24 13:38 ` Bjorn Helgaas [this message]
2019-07-24 15:48   ` Logan Gunthorpe
2019-07-25 13:21     ` Nicholas Johnson
2019-07-25 13:18   ` Nicholas Johnson
2019-07-25 15:50     ` Logan Gunthorpe
2019-08-04  8:47       ` Nicholas Johnson
2019-08-05  8:59         ` Nicholas Johnson
2019-08-05 12:34         ` Mika Westerberg
2019-08-05 14:09           ` Nicholas Johnson
2019-08-05 14:25           ` Nicholas Johnson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190724133814.GA194025@google.com \
    --to=helgaas@kernel.org \
    --cc=benh@kernel.crashing.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=logang@deltatee.com \
    --cc=mika.westerberg@linux.intel.com \
    --cc=nicholas.johnson-opensource@outlook.com.au \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).