From: Dave Hansen <dave.hansen@intel.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Lukasz Odzioba <lukasz.odzioba@intel.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
akpm@linux-foundation.org, kirill.shutemov@linux.intel.com,
aarcange@redhat.com, vdavydov@parallels.com, mingli199x@qq.com,
minchan@kernel.org, lukasz.anaczkowski@intel.com, "Shutemov,
Kirill" <kirill.shutemov@intel.com>
Subject: Re: [PATCH 1/1] mm/swap.c: flush lru_add pvecs on compound page arrival
Date: Wed, 8 Jun 2016 09:34:01 -0700 [thread overview]
Message-ID: <575848F9.2060501@intel.com> (raw)
In-Reply-To: <20160608160653.GB21838@dhcp22.suse.cz>
On 06/08/2016 09:06 AM, Michal Hocko wrote:
>> > Do we have any statistics that tell us how many pages are sitting the
>> > lru pvecs? Although this helps the problem overall, don't we still have
>> > a problem with memory being held in such an opaque place?
> Is it really worth bothering when we are talking about 56kB per CPU
> (after this patch)?
That was the logic why we didn't have it up until now: we didn't
*expect* it to get large. A code change blew it up by 512x, and we had
no instrumentation to tell us where all the memory went.
I guess we don't have any other ways to group pages than compound pages,
and _that_ one is covered now... for one of the 5 classes of pvecs.
Is there a good reason we don't have to touch the other 4 pagevecs, btw?
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next prev parent reply other threads:[~2016-06-08 16:34 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-08 14:35 [PATCH 1/1] mm/swap.c: flush lru_add pvecs on compound page arrival Lukasz Odzioba
2016-06-08 15:04 ` Michal Hocko
2016-06-09 8:01 ` Odzioba, Lukasz
2016-06-08 15:31 ` Dave Hansen
2016-06-08 16:06 ` Michal Hocko
2016-06-08 16:34 ` Dave Hansen [this message]
2016-06-09 12:21 ` Michal Hocko
2016-06-16 18:08 ` Odzioba, Lukasz
2016-06-16 18:19 ` Michal Hocko
2016-06-16 20:03 ` Odzioba, Lukasz
2016-06-09 8:50 ` Odzioba, Lukasz
2016-06-09 15:41 ` Dave Hansen
2016-06-13 21:01 ` Odzioba, Lukasz
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