From: Dave Hansen <dave.hansen@intel.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>,
Honglei Wang <honglei.wang@oracle.com>,
Johannes Weiner <hannes@cmpxchg.org>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>
Subject: Re: memcgroup lruvec_lru_size scaling issue
Date: Mon, 14 Oct 2019 11:11:52 -0700 [thread overview]
Message-ID: <8cb590af-ffca-624b-e30b-96f53d14cdc6@intel.com> (raw)
In-Reply-To: <20191014175918.GN317@dhcp22.suse.cz>
On 10/14/19 10:59 AM, Michal Hocko wrote:
>> It's just a theory, but it's why I noted the number of cgroups when I
>> initially saw this show up in profiles.
> Yes, the cache traffic might be really high but I still find it a bit
> surprising that it makes such a large footprint because this should be
> mostly called from slow paths (reclaim) and the real work done should
> just be larger - at least that's my intuition which might be quite off
> here. How much is that 25% of the system time in the total time btw?
The workload is a very read-heavy workload doing a lot of I/O.
Basically all the threads are going into direct reclaim a *LOT*.
The workload was roughly 50/50 user/kernel.
prev parent reply other threads:[~2019-10-14 18:11 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-14 17:17 memcgroup lruvec_lru_size scaling issue Tim Chen
2019-10-14 17:37 ` Michal Hocko
2019-10-14 17:49 ` Dave Hansen
2019-10-14 17:59 ` Michal Hocko
2019-10-14 18:06 ` Tim Chen
2019-10-14 18:31 ` Michal Hocko
2019-10-14 22:14 ` Andrew Morton
2019-10-15 6:19 ` Michal Hocko
2019-10-15 20:38 ` Andrew Morton
2019-10-16 7:25 ` Michal Hocko
2019-10-15 18:23 ` Tim Chen
2019-10-14 18:11 ` Dave Hansen [this message]
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