From: Peter Zijlstra <peterz@infradead.org>
To: Mike Kravetz <mike.kravetz@oracle.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Michal Hocko <mhocko@suse.com>,
Shakeel Butt <shakeelb@google.com>,
Oscar Salvador <osalvador@suse.de>,
David Hildenbrand <david@redhat.com>,
Muchun Song <songmuchun@bytedance.com>,
David Rientjes <rientjes@google.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Matthew Wilcox <willy@infradead.org>,
HORIGUCHI NAOYA <naoya.horiguchi@nec.com>,
"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
Waiman Long <longman@redhat.com>, Peter Xu <peterx@redhat.com>,
Mina Almasry <almasrymina@google.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [RFC PATCH 7/8] hugetlb: add update_and_free_page_no_sleep for irq context
Date: Mon, 22 Mar 2021 09:41:01 +0100 [thread overview]
Message-ID: <YFhYHZ9onwdZMeDi@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20210319224209.150047-8-mike.kravetz@oracle.com>
On Fri, Mar 19, 2021 at 03:42:08PM -0700, Mike Kravetz wrote:
> The locks acquired in free_huge_page are irq safe. However, in certain
> circumstances the routine update_and_free_page could sleep. Since
> free_huge_page can be called from any context, it can not sleep.
>
> Use a waitqueue to defer freeing of pages if the operation may sleep. A
> new routine update_and_free_page_no_sleep provides this functionality
> and is only called from free_huge_page.
>
> Note that any 'pages' sent to the workqueue for deferred freeing have
> already been removed from the hugetlb subsystem. What is actually
> deferred is returning those base pages to the low level allocator.
So maybe I'm stupid, but why do you need that work in hugetlb? Afaict it
should be in cma_release().
Also, afaict cma_release() does free_contig_range() *first*, and then
does the 'difficult' bits. So how about you re-order
free_gigantic_page() a bit to make it unconditionally do
free_contig_range() and *then* call into CMA, which can then do a
workqueue thingy if it feels like it.
That way none of the hugetlb accounting is delayed, and only CMA gets to
suffer.
next prev parent reply other threads:[~2021-03-22 8:41 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 22:42 [RFC PATCH 0/8] make hugetlb put_page safe for all calling contexts Mike Kravetz
2021-03-19 22:42 ` [RFC PATCH 1/8] hugetlb: add per-hstate mutex to synchronize user adjustments Mike Kravetz
2021-03-22 13:59 ` Michal Hocko
2021-03-22 16:57 ` Mike Kravetz
2021-03-23 7:48 ` Michal Hocko
2021-03-19 22:42 ` [RFC PATCH 2/8] hugetlb: recompute min_count when dropping hugetlb_lock Mike Kravetz
2021-03-22 14:07 ` Michal Hocko
2021-03-22 23:07 ` Mike Kravetz
2021-03-23 7:50 ` Michal Hocko
2021-03-23 8:01 ` Peter Zijlstra
2021-03-23 8:14 ` Michal Hocko
2021-03-23 23:18 ` Mike Kravetz
2021-03-24 8:36 ` Michal Hocko
2021-03-24 16:43 ` Mike Kravetz
2021-03-19 22:42 ` [RFC PATCH 3/8] hugetlb: create remove_hugetlb_page() to separate functionality Mike Kravetz
2021-03-22 14:15 ` Michal Hocko
2021-03-22 17:01 ` Mike Kravetz
2021-03-19 22:42 ` [RFC PATCH 4/8] hugetlb: call update_and_free_page without hugetlb_lock Mike Kravetz
2021-03-22 14:19 ` Michal Hocko
2021-03-19 22:42 ` [RFC PATCH 5/8] hugetlb: change free_pool_huge_page to remove_pool_huge_page Mike Kravetz
2021-03-22 14:31 ` Michal Hocko
2021-03-22 23:28 ` Mike Kravetz
2021-03-23 7:57 ` Michal Hocko
2021-03-24 1:03 ` Mike Kravetz
2021-03-24 8:40 ` Michal Hocko
2021-03-24 16:38 ` Mike Kravetz
2021-03-24 16:50 ` Michal Hocko
2021-03-19 22:42 ` [RFC PATCH 6/8] hugetlb: make free_huge_page irq safe Mike Kravetz
2021-03-21 19:55 ` Mike Kravetz
2021-03-22 13:36 ` [hugetlb] cd190f60f9: BUG:sleeping_function_called_from_invalid_context_at_mm/hugetlb.c kernel test robot
2021-03-22 14:35 ` [RFC PATCH 6/8] hugetlb: make free_huge_page irq safe Michal Hocko
2021-03-19 22:42 ` [RFC PATCH 7/8] hugetlb: add update_and_free_page_no_sleep for irq context Mike Kravetz
2021-03-20 1:18 ` Hillf Danton
2021-03-25 0:26 ` Mike Kravetz
2021-03-22 8:41 ` Peter Zijlstra [this message]
2021-03-22 17:42 ` Mike Kravetz
2021-03-22 18:10 ` Roman Gushchin
2021-03-23 18:51 ` Mike Kravetz
2021-03-23 19:07 ` Roman Gushchin
2021-03-24 8:43 ` Michal Hocko
2021-03-24 16:53 ` Mike Kravetz
2021-03-22 20:43 ` Peter Zijlstra
2021-03-22 14:42 ` Michal Hocko
2021-03-22 14:46 ` Michal Hocko
2021-03-19 22:42 ` [RFC PATCH 8/8] hugetlb: track hugetlb pages allocated via cma_alloc Mike Kravetz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YFhYHZ9onwdZMeDi@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=almasrymina@google.com \
--cc=aneesh.kumar@linux.ibm.com \
--cc=david@redhat.com \
--cc=linmiaohe@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=longman@redhat.com \
--cc=mhocko@suse.com \
--cc=mike.kravetz@oracle.com \
--cc=naoya.horiguchi@nec.com \
--cc=osalvador@suse.de \
--cc=peterx@redhat.com \
--cc=rientjes@google.com \
--cc=shakeelb@google.com \
--cc=songmuchun@bytedance.com \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).