From: Josh Poimboeuf <jpoimboe@kernel.org>
To: "Seth Forshee (DigitalOcean)" <sforshee@digitalocean.com>
Cc: Petr Mladek <pmladek@suse.com>, Jason Wang <jasowang@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Jiri Kosina <jikos@kernel.org>, Miroslav Benes <mbenes@suse.cz>,
Joe Lawrence <joe.lawrence@redhat.com>,
virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
netdev@vger.kernel.org, live-patching@vger.kernel.org,
linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH 0/2] vhost: improve livepatch switching for heavily loaded vhost worker kthreads
Date: Thu, 26 Jan 2023 20:43:55 -0800 [thread overview]
Message-ID: <20230127044355.frggdswx424kd5dq@treble> (raw)
In-Reply-To: <Y9LswwnPAf+nOVFG@do-x1extreme>
On Thu, Jan 26, 2023 at 03:12:35PM -0600, Seth Forshee (DigitalOcean) wrote:
> On Thu, Jan 26, 2023 at 06:03:16PM +0100, Petr Mladek wrote:
> > On Fri 2023-01-20 16:12:20, Seth Forshee (DigitalOcean) wrote:
> > > We've fairly regularaly seen liveptches which cannot transition within kpatch's
> > > timeout period due to busy vhost worker kthreads.
> >
> > I have missed this detail. Miroslav told me that we have solved
> > something similar some time ago, see
> > https://lore.kernel.org/all/20220507174628.2086373-1-song@kernel.org/
>
> Interesting thread. I had thought about something along the lines of the
> original patch, but there are some ideas in there that I hadn't
> considered.
Here's another idea, have we considered this? Have livepatch set
TIF_NEED_RESCHED on all kthreads to force them into schedule(), and then
have the scheduler call klp_try_switch_task() if TIF_PATCH_PENDING is
set.
Not sure how scheduler folks would feel about that ;-)
--
Josh
next prev parent reply other threads:[~2023-01-27 4:44 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-20 22:12 [PATCH 0/2] vhost: improve livepatch switching for heavily loaded vhost worker kthreads Seth Forshee (DigitalOcean)
2023-01-20 22:12 ` [PATCH 1/2] livepatch: add an interface for safely switching kthreads Seth Forshee (DigitalOcean)
2023-01-20 22:12 ` [PATCH 2/2] vhost: check for pending livepatches from vhost worker kthreads Seth Forshee (DigitalOcean)
2023-01-24 14:17 ` Petr Mladek
2023-01-24 17:21 ` Seth Forshee
2023-01-25 11:34 ` Petr Mladek
2023-01-25 16:57 ` Seth Forshee
2023-01-26 11:16 ` Petr Mladek
2023-01-26 11:49 ` Petr Mladek
2023-01-22 8:34 ` [PATCH 0/2] vhost: improve livepatch switching for heavily loaded " Michael S. Tsirkin
2023-01-26 17:03 ` Petr Mladek
2023-01-26 21:12 ` Seth Forshee (DigitalOcean)
2023-01-27 4:43 ` Josh Poimboeuf [this message]
2023-01-27 10:37 ` Peter Zijlstra
2023-01-27 12:09 ` Petr Mladek
2023-01-27 14:37 ` Seth Forshee
2023-01-27 16:52 ` Josh Poimboeuf
2023-01-27 17:09 ` Josh Poimboeuf
2023-01-27 22:11 ` Josh Poimboeuf
2023-01-30 12:40 ` Peter Zijlstra
2023-01-30 17:50 ` Seth Forshee
2023-01-30 18:18 ` Josh Poimboeuf
2023-01-30 18:36 ` Mark Rutland
2023-01-30 19:48 ` Josh Poimboeuf
2023-01-31 1:53 ` Song Liu
2023-01-31 10:22 ` Mark Rutland
2023-01-31 16:38 ` Josh Poimboeuf
2023-02-01 11:10 ` Mark Rutland
2023-02-01 16:57 ` Josh Poimboeuf
2023-02-01 17:11 ` Mark Rutland
2023-01-30 19:59 ` Josh Poimboeuf
2023-01-31 10:02 ` Peter Zijlstra
2023-01-27 20:02 ` Seth Forshee
2023-01-27 11:19 ` Petr Mladek
2023-01-27 14:57 ` Seth Forshee
2023-01-30 9:55 ` Petr Mladek
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