From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
John Fastabend <john.fastabend@gmail.com>
Subject: Re: [RFC PATCH 1/2] net: use cmpxchg instead of spinlock in ptr rings
Date: Tue, 15 Nov 2016 16:30:57 +0200 [thread overview]
Message-ID: <20161115162701-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20161115143258.2c46fc9a@redhat.com>
On Tue, Nov 15, 2016 at 02:32:58PM +0100, Jesper Dangaard Brouer wrote:
> What I would really like to see is a lock-free (locked cmpxchg) queue
> implementation, what like ptr_ring use the array as empty/full check,
> and still (somehow) support bulking.
I think lock-free is overrated for this use-case - we hold the lock
for such a short amount of time.
I think what we want is just a simpler spinlock - one that's faster than
qlock for use-cases that are unfair anyway, like this one where even if
you get the lock in a fair way, FIFO might be full and you won't be able
to queue.
Or find an API to add to FIFO in a fair way.
--
MST
next prev parent reply other threads:[~2016-11-15 14:30 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-15 13:32 [RFC PATCH 1/2] net: use cmpxchg instead of spinlock in ptr rings Jesper Dangaard Brouer
2016-11-15 14:30 ` Michael S. Tsirkin [this message]
2016-11-16 4:37 ` John Fastabend
-- strict thread matches above, loose matches on Subject: below --
2016-11-11 4:43 [RFC PATCH 0/2] illustrate cmpxchg ring for tap/tun and qdisc John Fastabend
2016-11-11 4:44 ` [RFC PATCH 1/2] net: use cmpxchg instead of spinlock in ptr rings John Fastabend
2016-11-14 11:09 ` Jesper Dangaard Brouer
2016-11-14 23:01 ` Michael S. Tsirkin
2016-11-16 4:30 ` John Fastabend
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