From: Vlastimil Babka <vbabka@suse.cz>
To: Mike Kravetz <mike.kravetz@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
David Hildenbrand <david@redhat.com>,
Michal Hocko <mhocko@suse.com>,
Oscar Salvador <osalvador@suse.de>, Zi Yan <ziy@nvidia.com>,
Muchun Song <songmuchun@bytedance.com>,
Naoya Horiguchi <naoya.horiguchi@linux.dev>,
David Rientjes <rientjes@google.com>,
Hillf Danton <hdanton@sina.com>
Subject: Re: [PATCH RESEND 0/8] hugetlb: add demote/split page functionality
Date: Fri, 27 Aug 2021 19:22:52 +0200 [thread overview]
Message-ID: <efcf6049-6110-d516-b21f-41bb8775f042@suse.cz> (raw)
In-Reply-To: <10d86c18-f0cf-395f-4209-17ac71b9fc03@oracle.com>
On 8/25/21 00:08, Mike Kravetz wrote:
> Add Vlastimil and Hillf,
>
> Well, I set up a test environment on a larger system to get some
> numbers. My 'load' on the system was filling the page cache with
> clean pages. The thought is that these pages could easily be reclaimed.
>
> When trying to get numbers I hit a hugetlb page allocation stall where
> __alloc_pages(__GFP_RETRY_MAYFAIL, order 9) would stall forever (or at
> least an hour). It was very much like the symptoms addressed here:
> https://lore.kernel.org/linux-mm/20190806014744.15446-1-mike.kravetz@oracle.com/
>
> This was on 5.14.0-rc6-next-20210820.
>
> I'll do some more digging as this appears to be some dark corner case of
> reclaim and/or compaction. The 'good news' is that I can reproduce
> this.
Interesting, let's see if that's some kind of new regression.
>> And the second problem would benefit from some words to help us
>> understand how much real-world hurt this causes, and how frequently.
>> And let's understand what the userspace workarounds look like, etc.
>
> The stall above was from doing a simple 'free 1GB page' followed by
> 'allocate 512 MB pages' from userspace.
Is the allocation different in any way than the usual hugepage allocation
possible today?
> Getting out another version of this series will be delayed, as I think
> we need to address or understand this issue first.
>
next prev parent reply other threads:[~2021-08-27 17:22 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-16 22:49 [PATCH RESEND 0/8] hugetlb: add demote/split page functionality Mike Kravetz
2021-08-16 22:49 ` [PATCH 1/8] hugetlb: add demote hugetlb page sysfs interfaces Mike Kravetz
2021-08-16 22:49 ` [PATCH 2/8] hugetlb: add HPageCma flag and code to free non-gigantic pages in CMA Mike Kravetz
2021-08-16 22:49 ` [PATCH 3/8] hugetlb: add demote bool to gigantic page routines Mike Kravetz
2021-08-16 22:49 ` [PATCH 4/8] hugetlb: add hugetlb demote page support Mike Kravetz
2021-08-16 22:49 ` [PATCH 5/8] hugetlb: document the demote sysfs interfaces Mike Kravetz
2021-08-16 23:28 ` Andrew Morton
2021-08-17 1:04 ` Mike Kravetz
2021-09-21 13:52 ` Aneesh Kumar K.V
2021-09-21 17:17 ` Mike Kravetz
2021-08-16 22:49 ` [PATCH 6/8] hugetlb: vmemmap optimizations when demoting hugetlb pages Mike Kravetz
2021-08-16 22:49 ` [PATCH 7/8] hugetlb: prepare destroy and prep routines for vmemmap optimized pages Mike Kravetz
2021-08-16 22:49 ` [PATCH 8/8] hugetlb: Optimized demote vmemmap optimizatized pages Mike Kravetz
2021-08-16 23:23 ` [PATCH RESEND 0/8] hugetlb: add demote/split page functionality Andrew Morton
2021-08-17 0:17 ` Mike Kravetz
2021-08-17 0:39 ` Andrew Morton
2021-08-17 0:58 ` Mike Kravetz
2021-08-16 23:27 ` Andrew Morton
2021-08-17 0:46 ` Mike Kravetz
2021-08-17 1:46 ` Andrew Morton
2021-08-17 7:30 ` David Hildenbrand
2021-08-17 16:19 ` Mike Kravetz
2021-08-17 18:49 ` David Hildenbrand
2021-08-24 22:08 ` Mike Kravetz
2021-08-26 7:32 ` Hillf Danton
2021-08-27 17:22 ` Vlastimil Babka [this message]
2021-08-27 23:04 ` Mike Kravetz
2021-08-30 10:11 ` Vlastimil Babka
2021-09-02 18:17 ` Mike Kravetz
2021-09-06 14:40 ` Vlastimil Babka
2021-09-07 8:50 ` Hillf Danton
2021-09-08 21:00 ` Mike Kravetz
2021-09-09 4:07 ` Hillf Danton
2021-09-09 11:54 ` Michal Hocko
2021-09-09 13:45 ` Vlastimil Babka
2021-09-09 21:31 ` Mike Kravetz
2021-09-10 8:20 ` Michal Hocko
2021-09-11 0:11 ` Mike Kravetz
2021-09-11 3:11 ` Hillf Danton
2021-09-13 15:50 ` Michal Hocko
2021-09-15 16:57 ` Mike Kravetz
2021-09-17 20:44 ` Mike Kravetz
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