From: Oleg Drokin <green@namesys.com>
To: "David S. Miller" <davem@redhat.com>
Cc: zaitcev@redhat.com, mingo@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: cmpxchg in 2.5.38
Date: Wed, 25 Sep 2002 12:07:25 +0400 [thread overview]
Message-ID: <20020925120725.A23559@namesys.com> (raw)
In-Reply-To: <20020925.004719.61852840.davem@redhat.com>
Hello!
On Wed, Sep 25, 2002 at 12:47:19AM -0700, David S. Miller wrote:
> Ingo said that arches that cannot do cmpxchg in hardware should
> provide spinlock-based version.
> That doesn't make any sense.
Yes, I know.
> If cmpxchg cannot work with user bits of memory, like
> cmpxchg is supposed to, it's really a crutch more than
> anything else.
Ingo's argument was that since there is only one place in code that accesses
that variable (map->page), it is safe to rely on such a crippled
cmpxchg implementation.
To not retell you whole story and avoid the role of broken phone,
here's info on prevous discussion on this topic:
Subject: Re: [patch] generic-pidhash-2.5.36-D4, BK-curr
September 20, From Ingo Molnar <mingo@elte.hu>, Message-ID: <Pine.LNX.4.44.0209201139290.1261-100000@localhost.localdomain>
September 20, From Ingo Molnar <mingo@elte.hu>, Message-ID: <Pine.LNX.4.44.0209201828090.8547-100000@localhost.localdomain>
Bye,
Oleg
next prev parent reply other threads:[~2002-09-25 8:02 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-09-25 5:00 cmpxchg in 2.5.38 Pete Zaitcev
2002-09-25 4:54 ` David S. Miller
2002-09-25 7:18 ` Oleg Drokin
2002-09-25 7:47 ` David S. Miller
2002-09-25 8:07 ` Oleg Drokin [this message]
2002-09-25 8:26 ` Ingo Molnar
2002-09-25 8:48 ` [patch] pidhash-2.5.38-A0 Ingo Molnar
2002-09-25 12:04 ` cmpxchg in 2.5.38 Geert Uytterhoeven
2002-09-25 17:42 ` Pete Zaitcev
2002-09-25 19:34 ` Ingo Molnar
2002-09-25 20:03 ` David S. Miller
2002-09-25 18:59 ` David S. Miller
2002-09-25 19:02 ` David S. Miller
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