From: David Miller <davem@davemloft.net>
To: torvalds@linux-foundation.org
Cc: heiko.carstens@de.ibm.com, akpm@linux-foundation.org,
a.p.zijlstra@chello.nl, mingo@elte.hu,
linux-arch@vger.kernel.org, schwidefsky@de.ibm.com,
arnd@arndb.de, horsth@linux.vnet.ibm.com,
ehrhardt@linux.vnet.ibm.com
Subject: Re: [patch 0/3] Allow inlined spinlocks again V3
Date: Fri, 14 Aug 2009 15:23:58 -0700 (PDT) [thread overview]
Message-ID: <20090814.152358.16603090.davem@davemloft.net> (raw)
In-Reply-To: <alpine.LFD.2.01.0908141350420.3162@localhost.localdomain>
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 14 Aug 2009 14:10:45 -0700 (PDT)
> On Fri, 14 Aug 2009, Linus Torvalds wrote:
>>
>> But not inline in the code, though. So yeah, it has a memory footprint,
>> but shouldn't have a cache footprint.
>
> An example of this: stack usage. This is the code with BUG_ON():
...
> and note how in the code, we're just jumping over something like four
> bytes ("ud2" plus that silly endless loop-jump just to make gcc happy
> are both 2 bytes on x86[-64]).
>
> Here's the same code with that horrid skb_under_panic():
Yes on x86 it's better even with verbose debugging because
of the inlining of the debug message pointer etc.
I'll have to do something more intelligent than I currently do on
sparc64, and I had always been meaning to do that. :-)
next prev parent reply other threads:[~2009-08-14 22:23 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-12 18:39 [patch 0/3] Allow inlined spinlocks again V3 Heiko Carstens
2009-08-12 18:39 ` [patch 1/3] spinlock: move spinlock function bodies to header file Heiko Carstens
2009-08-12 18:39 ` [patch 2/3] spinlock: allow inlined spinlocks Heiko Carstens
2009-08-12 18:39 ` [patch 3/3] spinlock: allow inlined spinlocks on s390 Heiko Carstens
2009-08-13 18:11 ` [patch 0/3] Allow inlined spinlocks again V3 Linus Torvalds
2009-08-13 18:34 ` Ingo Molnar
2009-08-13 18:43 ` Ingo Molnar
2009-08-14 12:34 ` Heiko Carstens
2009-08-14 16:04 ` Linus Torvalds
2009-08-14 17:13 ` Heiko Carstens
2009-08-14 18:08 ` Linus Torvalds
2009-08-14 20:19 ` David Miller
2009-08-14 20:45 ` Linus Torvalds
2009-08-14 21:10 ` Linus Torvalds
2009-08-14 22:23 ` David Miller [this message]
2009-08-16 18:27 ` Heiko Carstens
2009-08-16 18:45 ` Linus Torvalds
2009-08-16 20:36 ` Ingo Molnar
2009-08-17 10:26 ` Heiko Carstens
2009-08-17 21:26 ` [numbers] Re: [patch] more skb ops inlining Ingo Molnar
2009-08-18 11:34 ` Heiko Carstens
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