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Subject: Re: [PATCH v2 2/2] mm, slab: Show last shrink time in us when
 slab/shrink is read
To:     Michal Hocko <mhocko@kernel.org>
Cc:     Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, Roman Gushchin <guro@fb.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Shakeel Butt <shakeelb@google.com>,
        Vladimir Davydov <vdavydov.dev@gmail.com>
References: <20190717202413.13237-1-longman@redhat.com>
 <20190717202413.13237-3-longman@redhat.com>
 <20190719061410.GJ30461@dhcp22.suse.cz>
From:   Waiman Long <longman@redhat.com>
Organization: Red Hat
Message-ID: <a0ea7cd2-d66c-f251-d14f-979e0913c7ef@redhat.com>
Date:   Fri, 19 Jul 2019 10:07:20 -0400
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On 7/19/19 2:14 AM, Michal Hocko wrote:
> On Wed 17-07-19 16:24:13, Waiman Long wrote:
>> The show method of /sys/kernel/slab/<slab>/shrink sysfs file currently
>> returns nothing. This is now modified to show the time of the last
>> cache shrink operation in us.
> Isn't this something that tracing can be used for without any kernel
> modifications?

That is true, but it will be a bit more cumbersome to get the data.
Anyway, this is just a nice to have patch for me. I am perfectly fine
with dropping it if this does not prove to be that useful.

Thanks,
Longman