Re: [PATCH 04/11] qspinlock: Extract out the exchange of tail code word

2014-06-24 Thread Peter Zijlstra
On Wed, Jun 18, 2014 at 01:37:45PM +0200, Paolo Bonzini wrote: > However, I *do* agree with you that it's simpler to just squash this patch > into 01/11. So I explicitly broke out these optimizations into separate patches so that we can see them independently and agree they're idempotent wrt the s

Re: [PATCH 04/11] qspinlock: Extract out the exchange of tail code word

2014-06-18 Thread Konrad Rzeszutek Wilk
> >>However, I *do* agree with you that it's simpler to just squash this patch > >>into 01/11. > >Uh, did I say that? Oh I said why don't make it right the first time! > > > >I meant in terms of seperating the slowpath (aka the bytelock on the pending > >bit) from the queue (MCS code). Or renaming

Re: [PATCH 04/11] qspinlock: Extract out the exchange of tail code word

2014-06-18 Thread Paolo Bonzini
Il 18/06/2014 17:46, Waiman Long ha scritto: The #1 patch is nice by itself - as it lays out the foundation of the MCS-similar code - and if Ingo decides he does not want this pending byte-lock bit business - it can be easily reverted or dropped. The pending bit code is needed for performance

Re: [PATCH 04/11] qspinlock: Extract out the exchange of tail code word

2014-06-18 Thread Waiman Long
On 06/18/2014 09:50 AM, Konrad Rzeszutek Wilk wrote: On Wed, Jun 18, 2014 at 01:37:45PM +0200, Paolo Bonzini wrote: Il 17/06/2014 22:55, Konrad Rzeszutek Wilk ha scritto: On Sun, Jun 15, 2014 at 02:47:01PM +0200, Peter Zijlstra wrote: From: Waiman Long This patch extracts the logic for the ex

Re: [PATCH 04/11] qspinlock: Extract out the exchange of tail code word

2014-06-18 Thread Konrad Rzeszutek Wilk
On Wed, Jun 18, 2014 at 01:37:45PM +0200, Paolo Bonzini wrote: > Il 17/06/2014 22:55, Konrad Rzeszutek Wilk ha scritto: > >On Sun, Jun 15, 2014 at 02:47:01PM +0200, Peter Zijlstra wrote: > >>From: Waiman Long > >> > >>This patch extracts the logic for the exchange of new and previous tail > >>code

Re: [PATCH 04/11] qspinlock: Extract out the exchange of tail code word

2014-06-18 Thread Paolo Bonzini
Il 17/06/2014 22:55, Konrad Rzeszutek Wilk ha scritto: On Sun, Jun 15, 2014 at 02:47:01PM +0200, Peter Zijlstra wrote: From: Waiman Long This patch extracts the logic for the exchange of new and previous tail code words into a new xchg_tail() function which can be optimized in a later patch.

Re: [PATCH 04/11] qspinlock: Extract out the exchange of tail code word

2014-06-17 Thread Konrad Rzeszutek Wilk
On Sun, Jun 15, 2014 at 02:47:01PM +0200, Peter Zijlstra wrote: > From: Waiman Long > > This patch extracts the logic for the exchange of new and previous tail > code words into a new xchg_tail() function which can be optimized in a > later patch. And also adds a third try on acquiring the lock.

[PATCH 04/11] qspinlock: Extract out the exchange of tail code word

2014-06-15 Thread Peter Zijlstra
From: Waiman Long This patch extracts the logic for the exchange of new and previous tail code words into a new xchg_tail() function which can be optimized in a later patch. Signed-off-by: Waiman Long Signed-off-by: Peter Zijlstra --- include/asm-generic/qspinlock_types.h |2 + kernel/loc