Re: [PATCH 2/3] mm: page_counter: rearrange struct page_counter fields

[Shakeel Butt]

On Sun, Aug 21, 2022 at 5:24 PM Soheil Hassas Yeganeh <soheil@xxxxxxxxxx> wrote:
>
> On Sun, Aug 21, 2022 at 8:18 PM Shakeel Butt <shakeelb@xxxxxxxxxx> wrote:
> >
> > With memcg v2 enabled, memcg->memory.usage is a very hot member for
> > the workloads doing memcg charging on multiple CPUs concurrently.
> > Particularly the network intensive workloads. In addition, there is a
> > false cache sharing between memory.usage and memory.high on the charge
> > path. This patch moves the usage into a separate cacheline and move all
> > the read most fields into separate cacheline.
> >
> > To evaluate the impact of this optimization, on a 72 CPUs machine, we
> > ran the following workload in a three level of cgroup hierarchy with top
> > level having min and low setup appropriately. More specifically
> > memory.min equal to size of netperf binary and memory.low double of
> > that.
> >
> >  $ netserver -6
> >  # 36 instances of netperf with following params
> >  $ netperf -6 -H ::1 -l 60 -t TCP_SENDFILE -- -m 10K
> >
> > Results (average throughput of netperf):
> > Without (6.0-rc1)       10482.7 Mbps
> > With patch              12413.7 Mbps (18.4% improvement)
> >
> > With the patch, the throughput improved by 18.4%.
>
> Shakeel, for my understanding: is this on top of the gains from the
> previous patch?
>

No, this is independent of the previous patch. The cover letter has
the numbers for all three optimizations applied together.