From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dimitri Sivanich Message-Id: <200406012140.i51LeGjV043356@fsgi142.americas.sgi.com> Subject: Re: Slab cache reap and CPU availability Date: Tue, 1 Jun 2004 16:40:16 -0500 (CDT) In-Reply-To: <20040524145303.45c8f8a6.akpm@osdl.org> from "Andrew Morton" at May 24, 2004 02:53:03 PM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: > > Dimitri Sivanich wrote: > > > > The IA/64 backtrace with all the cruft removed looks as follows: > > > > 0xa000000100149ac0 reap_timer_fnc+0x100 > > 0xa0000001000f4d70 run_timer_softirq+0x2d0 > > 0xa0000001000e9440 __do_softirq+0x200 > > 0xa0000001000e94e0 do_softirq+0x80 > > 0xa000000100017f50 ia64_handle_irq+0x190 > > > > The system is running mostly AIM7, but I've seen holdoffs > 30 usec with > > virtually no load on the system. > > They're pretty low latencies you're talking about there. > > You should be able to reduce the amount of work in that timer handler by > limiting the size of the per-cpu caches in the slab allocator. You can do > that by writing a magic incantation to /proc/slabinfo or: > > --- 25/mm/slab.c~a Mon May 24 14:51:32 2004 > +++ 25-akpm/mm/slab.c Mon May 24 14:51:37 2004 > @@ -2642,6 +2642,7 @@ static void enable_cpucache (kmem_cache_ > if (limit > 32) > limit = 32; > #endif > + limit = 8; I tried several values for this limit, but these had little effect. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org