Re: [PATCH 0/2] Separate NUMA statistics from zone statistics

2017-08-22 Thread Dave Hansen
On 08/22/2017 06:14 PM, kemi wrote: > when performance is not important and when you want all tooling to work, you > set: > > sysctl vm.strict_stats=1 > > but if you can tolerate some possible tool breakage and some decreased > counter precision, you can do: > > sysctl vm.strict_sta

Re: [PATCH 0/2] Separate NUMA statistics from zone statistics

2017-08-22 Thread kemi
On 2017年08月23日 05:22, Christopher Lameter wrote: > Can we simple get rid of the stats or make then configurable (off by > defaut)? I agree they are rarely used and have been rarely used in the past. > I agree that we can make numa stats as well as other stats items that are rarely used configur

Re: [PATCH 0/2] Separate NUMA statistics from zone statistics

2017-08-22 Thread Andi Kleen
Christopher Lameter writes: > Can we simple get rid of the stats or make then configurable (off by > defaut)? I agree they are rarely used and have been rarely used in the past. > > Maybe some instrumentation for perf etc will allow > similar statistics these days? Thus its possible to drop them?

Re: [PATCH 0/2] Separate NUMA statistics from zone statistics

2017-08-22 Thread Christopher Lameter
Can we simple get rid of the stats or make then configurable (off by defaut)? I agree they are rarely used and have been rarely used in the past. Maybe some instrumentation for perf etc will allow similar statistics these days? Thus its possible to drop them? The space in the pcp pageset is preci

Re: [PATCH 0/2] Separate NUMA statistics from zone statistics

2017-08-15 Thread kemi
On 2017年08月15日 18:36, Jesper Dangaard Brouer wrote: > On Tue, 15 Aug 2017 16:45:34 +0800 > Kemi Wang wrote: > >> Each page allocation updates a set of per-zone statistics with a call to >> zone_statistics(). As discussed in 2017 MM submit, these are a substantial >

Re: [PATCH 0/2] Separate NUMA statistics from zone statistics

2017-08-15 Thread Jesper Dangaard Brouer
On Tue, 15 Aug 2017 16:45:34 +0800 Kemi Wang wrote: > Each page allocation updates a set of per-zone statistics with a call to > zone_statistics(). As discussed in 2017 MM submit, these are a substantial ^^ should be "summit" > source of overhead i

[PATCH 0/2] Separate NUMA statistics from zone statistics

2017-08-15 Thread Kemi Wang
Each page allocation updates a set of per-zone statistics with a call to zone_statistics(). As discussed in 2017 MM submit, these are a substantial source of overhead in the page allocator and are very rarely consumed. This significant overhead in cache bouncing caused by zone counters (NUMA associ