Re: Please revert [PATCH] user of the jiffies rounding patch: Slab
From: Christoph Lameter
Date: Mon Apr 30 2007 - 15:28:27 EST
On Mon, 30 Apr 2007, Arjan van de Ven wrote:
> Christoph Lameter wrote:
> > Umm you did not read the last bit of the description? It talks about firing
> > all timers on all cpus at once.
> >
>
> it talks about AVOIDING firing all timers on all cpus at once.
Hmmmm... Looked fine right now. Must have gotten the deep end before.
Ok. Could you review the new 1 HZ timer that I added to vmstat.c in mm and
make sure that it does the right thing? I'd like to have that one run at
an jiffy offset of 1 instead of 3 to give you more quiet time.
That one is only used for SMP. With SLUB there will be no periodic timers
at all for UP. SMP only has the vmstats update which should be quite
lightweight compared to the slab reaper and it does not need this long
period between them to be safe.
I'd like to have some ideas from you for NUMA. On NUMA I would like to
have all vm statistics refresh actions on each node be synchronized (which
would also significantly fix the situation on large NUMA for you).
I.e. on HZ the first cpus of each node run vmstats update, on HZ + 1 the
second cpu run its etc. How could we make that work?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/