Messages in this thread |  | | | Date | Mon, 18 Jan 2010 16:30:53 +0530 | | From | Balbir Singh <> | | Subject | Re: [PATCH] sched: cpuacct: Use bigger percpu counter batch values for stats counters |
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On Monday 18 January 2010 03:25 PM, Anton Blanchard wrote: > > Hi Martin, > >> For s390 the jiffies_to_cputime is a compile time constant. No need to >> initialize it at runtime, no? > > Indeed it is, I didn't look closely enough. Same with ia64 so no work to > do on either arch :) > >> The patch itself trades some accuracy (larger cpu accounting value that >> are stored per-cpu) against runtime overhead (spinlock to transfer the >> value to the global variable in __percpu_counter_add). Did you >> calculate how big the loss in accuracy is? > > The idea is we are already batching percpu_counter_batch jiffies, so > with CONFIG_VIRT_CPU_ACCOUNTING we batch the equivalent amount in > cputime. >
This patch worked well for me.
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Balbir Singh.
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