From: Michal Hocko <mhocko@suse.com>
To: Oscar Salvador <osalvador@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Roman Gushchin <guro@fb.com>, Shakeel Butt <shakeelb@google.com>,
David Hildenbrand <david@redhat.com>,
Muchun Song <songmuchun@bytedance.com>,
David Rientjes <rientjes@google.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Peter Zijlstra <peterz@infradead.org>,
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>,
Hillf Danton <hdanton@sina.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Barry Song <song.bao.hua@hisilicon.com>,
Will Deacon <will@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v4 5/8] hugetlb: call update_and_free_page without hugetlb_lock
Date: Wed, 7 Apr 2021 11:28:51 +0200 [thread overview]
Message-ID: <YG17U4PolKicoch8@dhcp22.suse.cz> (raw)
In-Reply-To: <20210407082744.GA10058@linux>
On Wed 07-04-21 10:27:49, Oscar Salvador wrote:
> On Mon, Apr 05, 2021 at 04:00:40PM -0700, Mike Kravetz wrote:
[...]
> > @@ -2671,22 +2682,34 @@ static void try_to_free_low(struct hstate *h, unsigned long count,
> > nodemask_t *nodes_allowed)
> > {
> > int i;
> > + struct page *page, *next;
> > + LIST_HEAD(page_list);
> >
> > if (hstate_is_gigantic(h))
> > return;
> >
> > + /*
> > + * Collect pages to be freed on a list, and free after dropping lock
> > + */
> > for_each_node_mask(i, *nodes_allowed) {
> > - struct page *page, *next;
> > struct list_head *freel = &h->hugepage_freelists[i];
> > list_for_each_entry_safe(page, next, freel, lru) {
> > if (count >= h->nr_huge_pages)
> > - return;
> > + goto out;
> > if (PageHighMem(page))
> > continue;
> > remove_hugetlb_page(h, page, false);
> > - update_and_free_page(h, page);
> > + list_add(&page->lru, &page_list);
> > }
> > }
> > +
> > +out:
> > + spin_unlock(&hugetlb_lock);
> > + list_for_each_entry_safe(page, next, &page_list, lru) {
> > + update_and_free_page(h, page);
> > + cond_resched();
> > + }
> > + spin_lock(&hugetlb_lock);
>
> Can we get here with an empty list?
An emoty page_list? If yes then sure, this can happen but
list_for_each_entry_safe will simply not iterate. Or what do you mean?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2021-04-07 9:29 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-05 23:00 [PATCH v4 0/8] make hugetlb put_page safe for all calling contexts Mike Kravetz
2021-04-05 23:00 ` [PATCH v4 1/8] mm/cma: change cma mutex to irq safe spinlock Mike Kravetz
2021-04-06 9:17 ` Peter Zijlstra
2021-04-06 9:35 ` Michal Hocko
2021-04-07 9:23 ` David Hildenbrand
2021-04-07 18:24 ` Roman Gushchin
2021-04-05 23:00 ` [PATCH v4 2/8] hugetlb: no need to drop hugetlb_lock to call cma_release Mike Kravetz
2021-04-06 7:18 ` Oscar Salvador
2021-04-07 9:26 ` David Hildenbrand
2021-04-05 23:00 ` [PATCH v4 3/8] hugetlb: add per-hstate mutex to synchronize user adjustments Mike Kravetz
2021-04-07 9:28 ` David Hildenbrand
2021-04-05 23:00 ` [PATCH v4 4/8] hugetlb: create remove_hugetlb_page() to separate functionality Mike Kravetz
2021-04-06 9:56 ` Michal Hocko
2021-04-06 12:50 ` Oscar Salvador
2021-04-06 16:49 ` Mike Kravetz
2021-04-06 17:57 ` Oscar Salvador
2021-04-07 8:21 ` Michal Hocko
2021-04-06 13:41 ` Oscar Salvador
2021-04-06 20:52 ` Mike Kravetz
2021-04-06 13:44 ` Oscar Salvador
2021-04-05 23:00 ` [PATCH v4 5/8] hugetlb: call update_and_free_page without hugetlb_lock Mike Kravetz
2021-04-06 9:57 ` Michal Hocko
2021-04-07 8:27 ` Oscar Salvador
2021-04-07 9:28 ` Michal Hocko [this message]
2021-04-07 9:37 ` Oscar Salvador
2021-04-05 23:00 ` [PATCH v4 6/8] hugetlb: change free_pool_huge_page to remove_pool_huge_page Mike Kravetz
2021-04-07 8:44 ` Oscar Salvador
2021-04-05 23:00 ` [PATCH v4 7/8] hugetlb: make free_huge_page irq safe Mike Kravetz
2021-04-07 9:12 ` Oscar Salvador
2021-04-07 9:33 ` Michal Hocko
2021-04-07 9:38 ` Oscar Salvador
2021-04-05 23:00 ` [PATCH v4 8/8] hugetlb: add lockdep_assert_held() calls for hugetlb_lock Mike Kravetz
2021-04-07 9:13 ` Oscar Salvador
2021-04-08 0:56 ` [PATCH v4 0/8] make hugetlb put_page safe for all calling contexts Mike Kravetz
2021-04-08 7:11 ` Oscar Salvador
2021-04-09 5:05 ` Andrew Morton
2021-04-09 20:43 ` Mike Kravetz
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