Messages in this thread | | | Date | Wed, 29 May 2013 12:26:05 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH v2 1/2] Make the batch size of the percpu_counter configurable |
| |
On Wed, 22 May 2013 16:37:18 -0700 Tim Chen <tim.c.chen@linux.intel.com> wrote:
> Currently the per cpu counter's batch size for memory accounting is > configured as twice the number of cpus in the system. However, > for system with very large memory, it is more appropriate to make it > proportional to the memory size per cpu in the system. > > For example, for a x86_64 system with 64 cpus and 128 GB of memory, > the batch size is only 2*64 pages (0.5 MB). So any memory accounting > changes of more than 0.5MB will overflow the per cpu counter into > the global counter. Instead, for the new scheme, the batch size > is configured to be 0.4% of the memory/cpu = 8MB (128 GB/64 /256), > which is more inline with the memory size.
I renamed the patch to "mm: tune vm_committed_as percpu_counter batching size".
Do we have any performance testing results? They're pretty important for a performance-improvement patch ;)
| |