From: Jeremy Fitzhardinge <jeremy@goop.org>
To: vatsa@linux.vnet.ibm.com
Cc: Peter Zijlstra <peterz@infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Nick Piggin <npiggin@suse.de>, Jan Beulich <JBeulich@novell.com>,
Avi Kivity <avi@redhat.com>,
Xen-devel <xen-devel@lists.xensource.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Linux Virtualization <virtualization@lists.linux-foundation.org>,
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Subject: Re: [PATCH 04/20] x86/ticketlock: make large and small ticket versions of spin_lock the same
Date: Fri, 12 Nov 2010 08:27:04 -0800 [thread overview]
Message-ID: <4CDD6AD8.5030003@goop.org> (raw)
In-Reply-To: <20101112121932.GA30016@linux.vnet.ibm.com>
On 11/12/2010 04:19 AM, Srivatsa Vaddagiri wrote:
> On Wed, Nov 03, 2010 at 10:59:45AM -0400, Jeremy Fitzhardinge wrote:
>> Make the bulk of __ticket_spin_lock look identical for large and small
>> number of cpus.
> [snip]
>
>> #if (NR_CPUS < 256)
>> static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock)
>> {
>> - register union {
>> - struct __raw_tickets tickets;
>> - unsigned short slock;
>> - } inc = { .slock = 1 << TICKET_SHIFT };
>> + register struct __raw_tickets inc = { .tail = 1 };
> [snip]
>
>> #else
>> static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock)
>> {
>> - unsigned inc = 1 << TICKET_SHIFT;
>> - __ticket_t tmp;
>> + register struct __raw_tickets inc = { .tickets.tail = 1 };
> s/.tickets//?
>
> Otherwise I get a compile error for NR_CPUS > 256, with just 4 patches applied.
Yeah, likely. That's precisely why I wanted to make them the same ;).
J
next prev parent reply other threads:[~2010-11-12 16:27 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-03 14:59 [PATCH 00/20] x86: ticket lock rewrite and paravirtualization Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 01/20] x86/ticketlock: clean up types and accessors Jeremy Fitzhardinge
2010-11-13 9:57 ` Américo Wang
2010-11-15 19:36 ` Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 02/20] x86/ticketlock: convert spin loop to C Jeremy Fitzhardinge
2010-11-03 15:11 ` Eric Dumazet
2010-11-03 15:38 ` Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 03/20] x86/ticketlock: Use C for __ticket_spin_unlock Jeremy Fitzhardinge
2010-11-03 15:13 ` Eric Dumazet
2010-11-03 18:00 ` Jeremy Fitzhardinge
2010-11-13 10:05 ` Américo Wang
2010-11-13 22:34 ` Paolo Bonzini
2010-11-15 19:38 ` Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 04/20] x86/ticketlock: make large and small ticket versions of spin_lock the same Jeremy Fitzhardinge
2010-11-12 12:19 ` Srivatsa Vaddagiri
2010-11-12 16:27 ` Jeremy Fitzhardinge [this message]
2010-11-03 14:59 ` [PATCH 05/20] x86/ticketlock: make __ticket_spin_lock common Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 06/20] x86/ticketlock: make __ticket_spin_trylock common Jeremy Fitzhardinge
2010-11-13 10:17 ` Américo Wang
2010-11-13 10:48 ` Eric Dumazet
2010-11-15 19:39 ` Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 07/20] x86/spinlocks: replace pv spinlocks with pv ticketlocks Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 08/20] x86/ticketlock: collapse a layer of functions Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 09/20] xen/pvticketlock: Xen implementation for PV ticket locks Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 10/20] x86/pvticketlock: keep count of blocked cpus Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 11/20] x86/pvticketlock: use callee-save for lock_spinning Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 12/20] x86/pvticketlock: use callee-save for unlock_kick as well Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 13/20] x86/pvticketlock: make sure unlock is seen by everyone before checking waiters Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 14/20] x86/ticketlock: loosen ordering restraints on unlock Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 15/20] x86/ticketlock: prevent compiler reordering into locked region Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 16/20] x86/ticketlock: don't inline _spin_unlock when using paravirt spinlocks Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 17/20] x86/ticketlock: clarify barrier in arch_spin_lock Jeremy Fitzhardinge
2010-11-03 14:59 ` [PATCH 18/20] x86/ticketlock: remove .slock Jeremy Fitzhardinge
2010-11-03 15:00 ` [PATCH 19/20] x86/ticketlocks: use overlapping read to eliminate mb() Jeremy Fitzhardinge
2010-11-03 15:00 ` [PATCH 20/20] x86/ticketlock: rename ticketpair to head_tail Jeremy Fitzhardinge
2010-11-12 22:12 ` [PATCH 00/20] x86: ticket lock rewrite and paravirtualization H. Peter Anvin
2010-11-12 22:17 ` Jeremy Fitzhardinge
2010-11-12 22:20 ` H. Peter Anvin
2010-11-15 20:00 ` Jeremy Fitzhardinge
2010-11-15 20:03 ` H. Peter Anvin
2010-11-15 20:14 ` Peter Zijlstra
2010-11-15 21:02 ` Jeremy Fitzhardinge
2010-11-15 21:08 ` Peter Zijlstra
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