Re: [PATCH] ext4: change the type of ext4 cache stats to percpu_counter to improve performance

From: Theodore Y. Ts'o
Date: Sun Aug 25 2019 - 20:48:19 EST

On Sun, Aug 25, 2019 at 10:28:03AM -0700, Eric Biggers wrote:
> This patch is causing the following. Probably because there's no calls to
> percpu_counter_destroy() for the new counters?

Yeah, I noticed this from my test runs last night as well. It looks
like original patch was never tested with CONFIG_HOTPLUG_CPU.

The other problem with this patch is that it initializes
es_stats_cache_hits and es_stats_cache_miesses too late. They will
get used when the journal inode is loaded. This is mostly harmless,
but it's also wrong.

I've dropped this patch from the ext4 git tree.

- Ted