From: "David S. Miller" <davem@redhat.com>
To: matts@ksu.edu
Cc: shemminger@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: 64 bit netdev stats counter
Date: Fri, 12 Jul 2002 14:58:35 -0700 (PDT) [thread overview]
Message-ID: <20020712.145835.91443486.davem@redhat.com> (raw)
In-Reply-To: <Pine.GSO.4.33L.0207121628100.19313-100000@unix2.cc.ksu.edu>
From: Matt Stegman <matts@ksu.edu>
Date: Fri, 12 Jul 2002 17:02:07 -0500 (CDT)
On 12 Jul 2002, Stephen Hemminger wrote:
> 64 bit values are not atomic so on x86 there will be glitches if this
> ever wraps over on an SMP machine. One other engineer is already
> adressing this for inode values like size; but this would introduce the
> same problem for network stuff.
One other solution I thought of would be to have an rx_bytes_wrap counter
in the struct.
32-bit values aren't atomic either, what is the issue?
We don't use atomic_t ops on these counters so they aren't
guarenteed in any way right now even. GCC is going to
output "incl MEM" or similar for net_stats->counter++, since
it lacks the 'lock;' prefix it is not atomic.
next prev parent reply other threads:[~2002-07-12 22:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1026503694.26819.4.camel@dell_ss3.pdx.osdl.net>
2002-07-12 22:02 ` 64 bit netdev stats counter Matt Stegman
2002-07-12 21:58 ` David S. Miller [this message]
2002-07-12 23:20 ` Alan Cox
2002-07-12 22:06 ` David S. Miller
2002-07-12 22:27 ` Andrew Morton
2002-07-12 22:28 ` David S. Miller
2002-07-12 22:31 ` Chris Friesen
2002-07-13 2:18 ` Alan Cox
2002-07-13 0:50 ` kuznet
2002-07-12 19:12 Matt Stegman
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