Re: [patch] sched: align rq to cacheline boundary

2007-04-10 Thread Siddha, Suresh B
On Tue, Apr 10, 2007 at 08:36:56AM +0200, Ingo Molnar wrote: > the runqueue is really supposed to be cacheline-isolated at _both_ ends > - at its beginning and at its end as well. Then either we need to define the first element in the struct as cacheline aligned or move into section where all the

Re: [patch] sched: align rq to cacheline boundary

2007-04-10 Thread Siddha, Suresh B
On Tue, Apr 10, 2007 at 08:24:22AM +0200, Ingo Molnar wrote: > > * Siddha, Suresh B <[EMAIL PROTECTED]> wrote: > > > Align the per cpu runqueue to the cacheline boundary. This will > > minimize the number of cachelines touched during remote wakeup. > > > -static DEFINE_PER_CPU(struct rq, runque

Re: [patch] sched: align rq to cacheline boundary

2007-04-10 Thread Andi Kleen
> > > > -static DEFINE_PER_CPU(struct rq, runqueues); > > +static DEFINE_PER_CPU(struct rq, runqueues) cacheline_aligned_in_smp; > > Remember that this can consume up to (linesize-4 * NR_CPUS) bytes, On x86 just the real possible map now -- that tends to be much smaller. There might be s

Re: [patch] sched: align rq to cacheline boundary

2007-04-09 Thread Ingo Molnar
* Andrew Morton <[EMAIL PROTECTED]> wrote: > > -static DEFINE_PER_CPU(struct rq, runqueues); > > +static DEFINE_PER_CPU(struct rq, runqueues) cacheline_aligned_in_smp; > > Remember that this can consume up to (linesize-4 * NR_CPUS) bytes, > which is rather a lot. yes - but one (special) is

Re: [patch] sched: align rq to cacheline boundary

2007-04-09 Thread Ingo Molnar
* Siddha, Suresh B <[EMAIL PROTECTED]> wrote: > Align the per cpu runqueue to the cacheline boundary. This will > minimize the number of cachelines touched during remote wakeup. > -static DEFINE_PER_CPU(struct rq, runqueues); > +static DEFINE_PER_CPU(struct rq, runqueues) cacheline_aligned_

Re: [patch] sched: align rq to cacheline boundary

2007-04-09 Thread Ravikiran G Thirumalai
On Mon, Apr 09, 2007 at 03:17:05PM -0700, Siddha, Suresh B wrote: > On Mon, Apr 09, 2007 at 02:53:09PM -0700, Ravikiran G Thirumalai wrote: > > On Mon, Apr 09, 2007 at 01:40:57PM -0700, Andrew Morton wrote: > > > On Mon, 9 Apr 2007 11:08:53 -0700 > > > "Siddha, Suresh B" <[EMAIL PROTECTED]> wrote:

Re: [patch] sched: align rq to cacheline boundary

2007-04-09 Thread Siddha, Suresh B
On Mon, Apr 09, 2007 at 02:53:09PM -0700, Ravikiran G Thirumalai wrote: > On Mon, Apr 09, 2007 at 01:40:57PM -0700, Andrew Morton wrote: > > On Mon, 9 Apr 2007 11:08:53 -0700 > > "Siddha, Suresh B" <[EMAIL PROTECTED]> wrote: > > > -static DEFINE_PER_CPU(struct rq, runqueues); > > > +static DEFINE_P

Re: [patch] sched: align rq to cacheline boundary

2007-04-09 Thread Ravikiran G Thirumalai
On Mon, Apr 09, 2007 at 01:40:57PM -0700, Andrew Morton wrote: > On Mon, 9 Apr 2007 11:08:53 -0700 > "Siddha, Suresh B" <[EMAIL PROTECTED]> wrote: > > > Align the per cpu runqueue to the cacheline boundary. This will minimize the > > number of cachelines touched during remote wakeup. > > > > Sign

Re: [patch] sched: align rq to cacheline boundary

2007-04-09 Thread Andrew Morton
On Mon, 9 Apr 2007 11:08:53 -0700 "Siddha, Suresh B" <[EMAIL PROTECTED]> wrote: > Align the per cpu runqueue to the cacheline boundary. This will minimize the > number of cachelines touched during remote wakeup. > > Signed-off-by: Suresh Siddha <[EMAIL PROTECTED]> > --- > > diff --git a/kernel/s

[patch] sched: align rq to cacheline boundary

2007-04-09 Thread Siddha, Suresh B
Align the per cpu runqueue to the cacheline boundary. This will minimize the number of cachelines touched during remote wakeup. Signed-off-by: Suresh Siddha <[EMAIL PROTECTED]> --- diff --git a/kernel/sched.c b/kernel/sched.c index b9a6837..eca33c5 100644 --- a/kernel/sched.c +++ b/kernel/sched.c