From: Gerd Hoffmann <kraxel@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: linux-pci@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] pciehp: fast unplug for virtual machines
Date: Fri, 12 Nov 2021 10:56:29 +0100 [thread overview]
Message-ID: <20211112095629.uoxfuhsvhicsdxgd@sirius.home.kraxel.org> (raw)
In-Reply-To: <20211111115931-mutt-send-email-mst@kernel.org>
Hi,
> > This patch adds the fast_virtual_unplug module parameter to the
> > pciehp driver. When enabled (which is the default) the linux
> > kernel will simply skip the delay for virtual pcie ports, which
> > reduces the total time for the unplug operation from 6-7 seconds
> > to 1-2 seconds.
>
> BTW how come it's still taking seconds, not milliseconds?
I've tackled the 5 seconds only, biggest chunk and easy target because
the only reason to have that is to allow operators press the attention
button again to cancel, so the risk to break something here is rather
low.
There are some more wait times elsewhere, to give the hardware the
time needed when powering up/down slots, which sum up to roughly one
second, and the time the driver needs to shutdown the device goes on
top of that (typically not much).
take care,
Gerd
next prev parent reply other threads:[~2021-11-12 9:56 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-11 9:02 [PATCH] pciehp: fast unplug for virtual machines Gerd Hoffmann
2021-11-11 17:00 ` Michael S. Tsirkin
2021-11-12 9:56 ` Gerd Hoffmann [this message]
2021-11-12 10:09 ` Michael S. Tsirkin
2021-11-11 21:50 ` Bjorn Helgaas
2021-11-12 11:28 ` Gerd Hoffmann
2021-11-12 0:00 ` Krzysztof Wilczyński
2021-11-14 16:39 ` Lukas Wunner
2021-11-14 17:24 ` Michael S. Tsirkin
2021-11-14 18:06 ` Lukas Wunner
2021-11-14 22:37 ` Michael S. Tsirkin
2021-11-15 9:59 ` Gerd Hoffmann
2021-11-15 7:45 ` Lukas Wunner
2021-11-15 10:09 ` Gerd Hoffmann
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=20211112095629.uoxfuhsvhicsdxgd@sirius.home.kraxel.org \
--to=kraxel@redhat.com \
--cc=bhelgaas@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=mst@redhat.com \
/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).