From: Matthew Wilcox <willy@infradead.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: Joe Damato <jdamato@fastly.com>,
netdev@vger.kernel.org, mkarsten@uwaterloo.ca,
amritha.nambiar@intel.com, sridhar.samudrala@intel.com,
sdf@fomichev.me, Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
"open list:FILESYSTEMS (VFS and infrastructure)"
<linux-fsdevel@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [RFC net-next 4/5] eventpoll: Trigger napi_busy_loop, if prefer_busy_poll is set
Date: Mon, 12 Aug 2024 17:17:38 +0100 [thread overview]
Message-ID: <Zro1onXfGkKoIRbY@casper.infradead.org> (raw)
In-Reply-To: <ZroL54bAzdR-Vr4d@infradead.org>
On Mon, Aug 12, 2024 at 06:19:35AM -0700, Christoph Hellwig wrote:
> On Mon, Aug 12, 2024 at 12:57:07PM +0000, Joe Damato wrote:
> > From: Martin Karsten <mkarsten@uwaterloo.ca>
> >
> > Setting prefer_busy_poll now leads to an effectively nonblocking
> > iteration though napi_busy_loop, even when busy_poll_usecs is 0.
>
> Hardcoding calls to the networking code from VFS code seems like
> a bad idea. Not that I disagree with the concept of disabling
> interrupts during busy polling, but this needs a proper abstraction
> through file_operations.
I don't understand what's going on with this patch set. Is it just
working around badly designed hardware? NVMe is specified in a way that
lets it be completely interruptless if the host is keeping up with the
incoming completions from the device (ie the device will interrupt if a
completion has been posted for N microseconds without being acknowledged).
I assumed this was how network devices worked too, but I didn't check.
next prev parent reply other threads:[~2024-08-12 16:17 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-12 12:57 [RFC net-next 0/5] Suspend IRQs during preferred busy poll Joe Damato
2024-08-12 12:57 ` [RFC net-next 4/5] eventpoll: Trigger napi_busy_loop, if prefer_busy_poll is set Joe Damato
2024-08-12 13:19 ` Christoph Hellwig
2024-08-12 16:17 ` Matthew Wilcox [this message]
2024-08-12 17:49 ` Joe Damato
2024-08-12 17:46 ` Joe Damato
2024-08-12 12:57 ` [RFC net-next 5/5] eventpoll: Control irq suspension for prefer_busy_poll Joe Damato
2024-08-12 20:20 ` Stanislav Fomichev
2024-08-12 21:47 ` Martin Karsten
2024-08-12 20:19 ` [RFC net-next 0/5] Suspend IRQs during preferred busy poll Stanislav Fomichev
2024-08-12 21:46 ` Martin Karsten
2024-08-12 23:03 ` Stanislav Fomichev
2024-08-13 0:04 ` Martin Karsten
2024-08-13 1:54 ` Stanislav Fomichev
2024-08-13 2:35 ` Martin Karsten
2024-08-13 4:07 ` Stanislav Fomichev
2024-08-13 13:18 ` Martin Karsten
2024-08-14 3:16 ` Willem de Bruijn
2024-08-14 14:19 ` Joe Damato
2024-08-14 15:08 ` Willem de Bruijn
2024-08-14 15:46 ` Joe Damato
2024-08-14 19:53 ` Samiullah Khawaja
2024-08-14 20:42 ` Martin Karsten
2024-08-16 14:27 ` Willem de Bruijn
2024-08-16 14:59 ` Willem de Bruijn
2024-08-16 15:25 ` Joe Damato
2024-08-16 17:01 ` Willem de Bruijn
2024-08-16 20:03 ` Martin Karsten
2024-08-16 20:58 ` Willem de Bruijn
2024-08-17 18:15 ` Martin Karsten
2024-08-18 12:55 ` Willem de Bruijn
2024-08-18 14:51 ` Martin Karsten
2024-08-20 2:36 ` Jakub Kicinski
2024-08-20 14:28 ` Martin Karsten
2024-08-17 10:00 ` Joe Damato
2024-08-14 0:10 ` Jakub Kicinski
2024-08-14 1:14 ` Martin Karsten
2024-08-20 2:07 ` Jakub Kicinski
2024-08-20 14:27 ` Martin Karsten
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=Zro1onXfGkKoIRbY@casper.infradead.org \
--to=willy@infradead.org \
--cc=amritha.nambiar@intel.com \
--cc=brauner@kernel.org \
--cc=hch@infradead.org \
--cc=jack@suse.cz \
--cc=jdamato@fastly.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mkarsten@uwaterloo.ca \
--cc=netdev@vger.kernel.org \
--cc=sdf@fomichev.me \
--cc=sridhar.samudrala@intel.com \
--cc=viro@zeniv.linux.org.uk \
/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).