From: "H. Peter Anvin" <hpa@zytor.com>
To: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>,
David Rientjes <rientjes@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
linux-mm@kvack.org, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [slubllv5 07/25] x86: Add support for cmpxchg_double
Date: Thu, 26 May 2011 11:29:21 -0700 [thread overview]
Message-ID: <4DDE9C01.2090104@zytor.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1105261315350.26578@router.home>
On 05/26/2011 11:17 AM, Christoph Lameter wrote:
> On Thu, 26 May 2011, H. Peter Anvin wrote:
>
>>> +config CMPXCHG_DOUBLE
>>> + def_bool X86_64 || (X86_32 && !M386)
>>> +
>>
>> CMPXCHG16B is not a baseline feature for the Linux x86-64 build, and
>> CMPXCHG8G is a Pentium, not a 486, feature.
>>
>> Nacked-by: H. Peter Anvin <hpa@zytor.com>
>
> Hmmm... We may have to call it CONFIG_CMPXCHG_DOUBLE_POSSIBLE then?
>
> Because the slub code tests the flag in the processor and will not use the
> cmpxchg16b from the allocator if its not there. It will then fallback to
> using a bit lock in page struct.
>
Well, if it is just about being "possible" then it should simply be true
for all of x86. There is no reason to exclude i386 (which is all your
above predicate does, it is exactly equivalent to !M386).
-hpa
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next prev parent reply other threads:[~2011-05-26 18:35 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-16 20:26 [slubllv5 00/25] SLUB: Lockless freelists for objects V5 Christoph Lameter
2011-05-16 20:26 ` [slubllv5 01/25] slub: Avoid warning for !CONFIG_SLUB_DEBUG Christoph Lameter
2011-05-16 20:26 ` [slubllv5 02/25] slub: Fix control flow in slab_alloc Christoph Lameter
2011-05-16 20:26 ` [slubllv5 03/25] slub: Make CONFIG_PAGE_ALLOC work with new fastpath Christoph Lameter
2011-05-17 4:52 ` Eric Dumazet
2011-05-17 13:46 ` Christoph Lameter
2011-05-17 19:22 ` Pekka Enberg
2011-05-16 20:26 ` [slubllv5 04/25] slub: Push irq disable into allocate_slab() Christoph Lameter
2011-05-16 20:26 ` [slubllv5 05/25] slub: Do not use frozen page flag but a bit in the page counters Christoph Lameter
2011-05-16 20:26 ` [slubllv5 06/25] slub: Move page->frozen handling near where the page->freelist handling occurs Christoph Lameter
2011-05-16 20:26 ` [slubllv5 07/25] x86: Add support for cmpxchg_double Christoph Lameter
2011-05-26 17:57 ` Pekka Enberg
2011-05-26 18:02 ` Christoph Lameter
2011-05-26 18:05 ` H. Peter Anvin
2011-05-26 18:17 ` Christoph Lameter
2011-05-26 18:29 ` H. Peter Anvin [this message]
2011-05-26 18:42 ` Christoph Lameter
2011-05-26 21:16 ` Christoph Lameter
2011-05-26 21:21 ` H. Peter Anvin
2011-05-26 21:25 ` Eric Dumazet
2011-05-26 21:31 ` H. Peter Anvin
2011-05-26 21:45 ` Eric Dumazet
2011-05-27 0:49 ` H. Peter Anvin
2011-05-31 15:13 ` Christoph Lameter
2011-05-31 15:16 ` H. Peter Anvin
2011-05-31 16:53 ` Christoph Lameter
2011-05-31 23:16 ` H. Peter Anvin
2011-05-31 23:49 ` Christoph Lameter
2011-05-31 23:54 ` H. Peter Anvin
2011-06-01 14:13 ` Christoph Lameter
2011-06-01 14:46 ` Christoph Lameter
2011-06-01 15:42 ` H. Peter Anvin
2011-06-01 16:08 ` Christoph Lameter
2011-06-01 15:41 ` H. Peter Anvin
2011-05-27 0:50 ` H. Peter Anvin
2011-05-31 15:10 ` Christoph Lameter
2011-05-16 20:26 ` [slubllv5 08/25] mm: Rearrange struct page Christoph Lameter
2011-05-16 20:26 ` [slubllv5 09/25] slub: Add cmpxchg_double_slab() Christoph Lameter
2011-05-16 20:26 ` [slubllv5 10/25] slub: explicit list_lock taking Christoph Lameter
2011-05-16 20:26 ` [slubllv5 11/25] slub: Pass kmem_cache struct to lock and freeze slab Christoph Lameter
2011-05-16 20:26 ` [slubllv5 12/25] slub: Rework allocator fastpaths Christoph Lameter
2011-05-16 20:26 ` [slubllv5 13/25] slub: Invert locking and avoid slab lock Christoph Lameter
2011-05-16 20:26 ` [slubllv5 14/25] slub: Disable interrupts in free_debug processing Christoph Lameter
2011-05-16 20:26 ` [slubllv5 15/25] slub: Avoid disabling interrupts in free slowpath Christoph Lameter
2011-05-16 20:26 ` [slubllv5 16/25] slub: Get rid of the another_slab label Christoph Lameter
2011-05-16 20:26 ` [slubllv5 17/25] slub: Add statistics for the case that the current slab does not match the node Christoph Lameter
2011-05-16 20:26 ` [slubllv5 18/25] slub: fast release on full slab Christoph Lameter
2011-05-16 20:26 ` [slubllv5 19/25] slub: Not necessary to check for empty slab on load_freelist Christoph Lameter
2011-05-16 20:26 ` [slubllv5 20/25] slub: slabinfo update for cmpxchg handling Christoph Lameter
2011-05-16 20:26 ` [slubllv5 21/25] slub: Prepare inuse field in new_slab() Christoph Lameter
2011-05-16 20:26 ` [slubllv5 22/25] slub: pass kmem_cache_cpu pointer to get_partial() Christoph Lameter
2011-05-16 20:26 ` [slubllv5 23/25] slub: return object pointer from get_partial() / new_slab() Christoph Lameter
2011-05-16 20:26 ` [slubllv5 24/25] slub: Remove gotos from __slab_free() Christoph Lameter
2011-05-16 20:26 ` [slubllv5 25/25] slub: Remove gotos from __slab_alloc() Christoph Lameter
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