Re: [LKP] [mm] 3484b2de949: -46.2% aim7.jobs-per-min

Mel Gorman
2015-02-27T11:53:11Z

On Fri, Feb 27, 2015 at 03:21:36PM +0800, Huang Ying wrote:
> FYI, we noticed the below changes on
>
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> commit 3484b2de9499df23c4604a513b36f96326ae81ad ("mm: rearrange zone fields into read-only, page alloc, statistics and page reclaim lines")
>
> The perf cpu-cycles for spinlock (zone->lock) increased a lot. I suspect there are some cache ping-pong or false sharing.
>

Annoying because this is pretty much the opposite of what I found during
testing. What is the kernel config? Similar to the kernel config, can you
post "pahole -C zone vmlinux" for the kernel you built? I should get the same
result if I use the same kernel config but no harm in being sure. Thanks.

--
Mel Gorman
SUSE Labs