From: "Jörn Engel" <joern@purestorage.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Spencer Baugh <sbaugh@catern.com>,
Andrew Morton <akpm@linux-foundation.org>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
David Rientjes <rientjes@google.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Mike Kravetz <mike.kravetz@oracle.com>,
Luiz Capitulino <lcapitulino@redhat.com>,
"open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>,
open list <linux-kernel@vger.kernel.org>,
Spencer Baugh <Spencer.baugh@purestorage.com>,
Joern Engel <joern@logfs.org>
Subject: Re: [PATCH] hugetlb: cond_resched for set_max_huge_pages and follow_hugetlb_page
Date: Fri, 24 Jul 2015 10:12:37 -0700 [thread overview]
Message-ID: <20150724171237.GC3458@Sligo.logfs.org> (raw)
In-Reply-To: <20150724065959.GB4622@dhcp22.suse.cz>
On Fri, Jul 24, 2015 at 08:59:59AM +0200, Michal Hocko wrote:
> On Thu 23-07-15 14:54:31, Spencer Baugh wrote:
> > From: Joern Engel <joern@logfs.org>
> >
> > ~150ms scheduler latency for both observed in the wild.
>
> This is way to vague. Could you describe your problem somehow more,
> please?
> There are schduling points in the page allocator (when it triggers the
> reclaim), why are those not sufficient? Or do you manage to allocate
> many hugetlb pages without performing the reclaim and that leads to
> soft lockups?
We don't use transparent hugepages - they cause too much latency.
Instead we reserve somewhere around 3/4 or so of physical memory for
hugepages. "sysctl -w vm.nr_hugepages=100000" or something similar in a
startup script.
Since it is early in boot we don't go through page reclaim.
Jorn
--
Everything should be made as simple as possible, but not simpler.
-- Albert Einstein
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WARNING: multiple messages have this Message-ID (diff)
From: "Jörn Engel" <joern@purestorage.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Spencer Baugh <sbaugh@catern.com>,
Andrew Morton <akpm@linux-foundation.org>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
David Rientjes <rientjes@google.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Mike Kravetz <mike.kravetz@oracle.com>,
Luiz Capitulino <lcapitulino@redhat.com>,
"open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>,
open list <linux-kernel@vger.kernel.org>,
Spencer Baugh <Spencer.baugh@purestorage.com>,
Joern Engel <joern@logfs.org>
Subject: Re: [PATCH] hugetlb: cond_resched for set_max_huge_pages and follow_hugetlb_page
Date: Fri, 24 Jul 2015 10:12:37 -0700 [thread overview]
Message-ID: <20150724171237.GC3458@Sligo.logfs.org> (raw)
In-Reply-To: <20150724065959.GB4622@dhcp22.suse.cz>
On Fri, Jul 24, 2015 at 08:59:59AM +0200, Michal Hocko wrote:
> On Thu 23-07-15 14:54:31, Spencer Baugh wrote:
> > From: Joern Engel <joern@logfs.org>
> >
> > ~150ms scheduler latency for both observed in the wild.
>
> This is way to vague. Could you describe your problem somehow more,
> please?
> There are schduling points in the page allocator (when it triggers the
> reclaim), why are those not sufficient? Or do you manage to allocate
> many hugetlb pages without performing the reclaim and that leads to
> soft lockups?
We don't use transparent hugepages - they cause too much latency.
Instead we reserve somewhere around 3/4 or so of physical memory for
hugepages. "sysctl -w vm.nr_hugepages=100000" or something similar in a
startup script.
Since it is early in boot we don't go through page reclaim.
Jörn
--
Everything should be made as simple as possible, but not simpler.
-- Albert Einstein
next prev parent reply other threads:[~2015-07-24 17:12 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-23 21:54 [PATCH] hugetlb: cond_resched for set_max_huge_pages and follow_hugetlb_page Spencer Baugh
2015-07-23 21:54 ` Spencer Baugh
2015-07-23 22:08 ` David Rientjes
2015-07-23 22:08 ` David Rientjes
2015-07-23 22:36 ` Jörn Engel
2015-07-23 22:36 ` Jörn Engel
2015-07-23 22:54 ` David Rientjes
2015-07-23 22:54 ` David Rientjes
2015-07-23 23:09 ` Jörn Engel
2015-07-23 23:09 ` Jörn Engel
2015-07-24 19:49 ` David Rientjes
2015-07-24 19:49 ` David Rientjes
2015-07-24 20:49 ` Jörn Engel
2015-07-24 20:49 ` Jörn Engel
2015-07-24 6:59 ` Michal Hocko
2015-07-24 6:59 ` Michal Hocko
2015-07-24 17:12 ` Jörn Engel [this message]
2015-07-24 17:12 ` Jörn Engel
2015-07-24 20:28 ` Davidlohr Bueso
2015-07-24 20:28 ` Davidlohr Bueso
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