From d1187ed21026fd512b87851d0ca26d9ae16f9059 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 9 May 2007 02:35:12 -0700 Subject: vmstat: use our own timer events vmstat is currently using the cache reaper to periodically bring the statistics up to date. The cache reaper does only exists in SLUB as a way to provide compatibility with SLAB. This patch removes the vmstat calls from the slab allocators and provides its own handling. The advantage is also that we can use a different frequency for the updates. Refreshing vm stats is a pretty fast job so we can run this every second and stagger this by only one tick. This will lead to some overlap in large systems. F.e a system running at 250 HZ with 1024 processors will have 4 vm updates occurring at once. However, the vm stats update only accesses per node information. It is only necessary to stagger the vm statistics updates per processor in each node. Vm counter updates occurring on distant nodes will not cause cacheline contention. We could implement an alternate approach that runs the first processor on each node at the second and then each of the other processor on a node on a subsequent tick. That may be useful to keep a large amount of the second free of timer activity. Maybe the timer folks will have some feedback on this one? [jirislaby@gmail.com: add missing break] Cc: Arjan van de Ven Signed-off-by: Christoph Lameter Signed-off-by: Jiri Slaby Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 1 - 1 file changed, 1 deletion(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index 6f3d6e240c6..e50908b2bfa 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -4156,7 +4156,6 @@ next: check_irq_on(); mutex_unlock(&cache_chain_mutex); next_reap_node(); - refresh_cpu_vm_stats(smp_processor_id()); out: /* Set up the next iteration */ schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); -- cgit v1.2.3