Messages in this thread | | | Date | Sun, 12 Aug 2007 17:51:18 +0200 (CEST) | From | Jan Engelhardt <> | Subject | Re: [patch 01/23] Fall back on interrupt disable in cmpxchg8b on 80386 and 80486 |
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On Aug 12 2007 10:54, Mathieu Desnoyers wrote:
>Date: Sun, 12 Aug 2007 10:54:35 -0400 >From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> >To: <akpm@linux-foundation.org>, <linux-kernel@vger.kernel.org> >Cc: Christoph Lameter <clameter@sgi.com>, > Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>, <mingo@redhat.com> >Subject: [patch 01/23] Fall back on interrupt disable in cmpxchg8b on 80386 and > 80486 > >Actually, on 386, cmpxchg and cmpxchg_local fall back on >cmpxchg_386_u8/16/32: it disables interruptions around non atomic >updates to mimic the cmpxchg behavior. > >The comment: >/* Poor man's cmpxchg for 386. Unsuitable for SMP */ > >already present in cmpxchg_386_u32 tells much about how this cmpxchg >implementation should not be used in a SMP context. However, the cmpxchg_local >can perfectly use this fallback, since it only needs to be atomic wrt the local >cpu. > >This patch adds a cmpxchg_486_u64 and uses it as a fallback for cmpxchg64 >and cmpxchg64_local on 80386 and 80486.
hm, but why is it called cmpxchg_486 when the other functions are called cmpxchg_386?
Jan -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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