All of lore.kernel.org
 help / color / mirror / Atom feed
From: Stephen Hemminger <stephen@networkplumber.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: netdev@vger.kernel.org,
	virtualization@lists.linux-foundation.org, tglx@linutronix.de,
	Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Jason Wang <jasowang@redhat.com>,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [RFC] virtio_net: add local_bh_disable() around u64_stats_update_begin
Date: Tue, 16 Oct 2018 11:01:14 -0700	[thread overview]
Message-ID: <20181016110114.73e2b248@xeon-e3> (raw)
In-Reply-To: <20181016165545.guksrl23ulcudxrk@linutronix.de>

On Tue, 16 Oct 2018 18:55:45 +0200
Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:

> Also, ptr->var++ is not an atomic operation even on 64bit CPUs. Which
> means if try_fill_recv() runs on CPU0 (via virtnet_receive()) then the
> worker might run on CPU1.

On modern CPU's increment of native types is atomic but not locked.
u64_stats_update_begin is a no-op on UP and also if BIT_PER_LONG != 32

  parent reply	other threads:[~2018-10-17  1:52 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-16 16:55 [RFC] virtio_net: add local_bh_disable() around u64_stats_update_begin Sebastian Andrzej Siewior
2018-10-16 17:59 ` Stephen Hemminger
2018-10-16 18:21   ` Sebastian Andrzej Siewior
2018-10-16 17:59 ` Stephen Hemminger
2018-10-16 18:01 ` Stephen Hemminger [this message]
2018-10-16 18:42   ` Sebastian Andrzej Siewior
2018-10-16 18:42   ` Sebastian Andrzej Siewior
2018-10-16 18:44     ` Stephen Hemminger
2018-10-16 18:44     ` Stephen Hemminger
2018-10-18  8:43       ` [PATCH] " Sebastian Andrzej Siewior
2018-10-18  9:06         ` Toshiaki Makita
2018-10-18  9:11           ` Sebastian Andrzej Siewior
2018-10-18  9:11           ` Sebastian Andrzej Siewior
2018-10-18  9:26             ` Toshiaki Makita
2018-10-18 23:23         ` David Miller
2018-10-19  2:19           ` Jason Wang
2018-10-19  2:19           ` Jason Wang
2018-10-18  8:43       ` Sebastian Andrzej Siewior
2018-10-16 18:01 ` [RFC] " Stephen Hemminger
2018-10-17  1:13 ` Toshiaki Makita
2018-10-17  1:13 ` Toshiaki Makita
2018-10-17  6:48   ` Jason Wang
2018-10-18  8:47     ` Sebastian Andrzej Siewior
2018-10-18  8:47     ` Sebastian Andrzej Siewior
2018-10-18  9:00       ` Toshiaki Makita
2018-10-18  9:08         ` Sebastian Andrzej Siewior
2018-10-18  9:19           ` Toshiaki Makita
2018-10-18  9:30             ` Sebastian Andrzej Siewior
2018-10-18  9:30             ` Sebastian Andrzej Siewior
2018-10-18  9:53               ` Toshiaki Makita
2018-10-18 13:21             ` Rafael David Tinoco
2018-10-18  9:08         ` Sebastian Andrzej Siewior
2018-10-19  2:17       ` Jason Wang
2018-10-19  2:17       ` Jason Wang
2018-10-17  6:48   ` Jason Wang
  -- strict thread matches above, loose matches on Subject: below --
2018-10-16 16:55 Sebastian Andrzej Siewior

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=20181016110114.73e2b248@xeon-e3 \
    --to=stephen@networkplumber.org \
    --cc=bigeasy@linutronix.de \
    --cc=davem@davemloft.net \
    --cc=jasowang@redhat.com \
    --cc=makita.toshiaki@lab.ntt.co.jp \
    --cc=mst@redhat.com \
    --cc=netdev@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=virtualization@lists.linux-foundation.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.