From: Vlastimil Babka <vbabka@suse.cz>
To: Joonsoo Kim <js1304@gmail.com>, Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux Memory Management List <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
kernel-team@lge.com, Christoph Hellwig <hch@infradead.org>,
Roman Gushchin <guro@fb.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [PATCH v3 3/8] mm/hugetlb: unify migration callbacks
Date: Thu, 2 Jul 2020 18:13:06 +0200 [thread overview]
Message-ID: <c3d97171-b36a-338b-5e5c-360bb52ffe0c@suse.cz> (raw)
In-Reply-To: <CAAmzW4N646-xYWosMwwnOgjAB+Z_eoZO4rs58ab+gYbHXmydJA@mail.gmail.com>
On 6/26/20 6:02 AM, Joonsoo Kim wrote:
> 2020년 6월 25일 (목) 오후 8:26, Michal Hocko <mhocko@kernel.org>님이 작성:
>>
>> On Tue 23-06-20 15:13:43, Joonsoo Kim wrote:
>> > From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
>> >
>> > There is no difference between two migration callback functions,
>> > alloc_huge_page_node() and alloc_huge_page_nodemask(), except
>> > __GFP_THISNODE handling. This patch adds an argument, gfp_mask, on
>> > alloc_huge_page_nodemask() and replace the callsite for
>> > alloc_huge_page_node() with the call to
>> > alloc_huge_page_nodemask(..., __GFP_THISNODE).
>> >
>> > It's safe to remove a node id check in alloc_huge_page_node() since
>> > there is no caller passing NUMA_NO_NODE as a node id.
>>
>> Yes this is indeed safe. alloc_huge_page_node used to be called from
>> other internal hugetlb allocation layer and that allowed NUMA_NO_NODE as
>> well. Now it is called only from the mempolicy migration callback and
>> that always specifies a node and want to stick with that node.
>>
>> But I have to say I really dislike the gfp semantic because it is
>> different from any other allocation function I can think of. It
>> specifies what to be added rather than what should be used.
>>
>> Removing the function is ok but please use the full gfp mask instead
>> or if that is impractical for some reason (wich shouldn't be the case
>> as htlb_alloc_mask should be trivial to make static inline) make it
>> explicit that this is not a gfp_mask but a gfp modifier and explicitly
>> state which modifiers are allowed.
>
> Okay. I will try to solve your concern. Concrete solution is not yet prepared
> but perhaps I will use full gfp_mask by using htlb_alloc_mask() in caller sites.
Yeah, that should be feasible. alloc_huge_page_vma() already does
htlb_alloc_mask(h). In alloc_new_node_page() and new_page_nodemask() it would be
consistent with the other cases handled there (THP and base).
> Thanks.
>
next prev parent reply other threads:[~2020-07-02 16:13 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 6:13 [PATCH v3 0/8] clean-up the migration target allocation functions js1304
2020-06-23 6:13 ` [PATCH v3 1/8] mm/page_isolation: prefer the node of the source page js1304
2020-06-23 6:13 ` [PATCH v3 2/8] mm/migrate: move migration helper from .h to .c js1304
2020-06-23 6:13 ` [PATCH v3 3/8] mm/hugetlb: unify migration callbacks js1304
2020-06-24 21:18 ` Mike Kravetz
2020-06-25 11:26 ` Michal Hocko
2020-06-26 4:02 ` Joonsoo Kim
2020-07-02 16:13 ` Vlastimil Babka [this message]
2020-07-03 0:55 ` Joonsoo Kim
2020-06-23 6:13 ` [PATCH v3 4/8] mm/hugetlb: make hugetlb migration callback CMA aware js1304
2020-06-25 11:54 ` Michal Hocko
2020-06-26 4:49 ` Joonsoo Kim
2020-06-26 7:23 ` Michal Hocko
2020-06-29 6:27 ` Joonsoo Kim
2020-06-29 7:55 ` Michal Hocko
2020-06-30 6:30 ` Joonsoo Kim
2020-06-30 6:42 ` Michal Hocko
2020-06-30 7:22 ` Joonsoo Kim
2020-06-30 16:37 ` Mike Kravetz
2020-06-23 6:13 ` [PATCH v3 5/8] mm/migrate: make a standard migration target allocation function js1304
2020-06-25 12:05 ` Michal Hocko
2020-06-26 5:02 ` Joonsoo Kim
2020-06-26 7:33 ` Michal Hocko
2020-06-29 6:41 ` Joonsoo Kim
2020-06-29 8:03 ` Michal Hocko
2020-06-30 7:19 ` Joonsoo Kim
2020-07-03 15:25 ` Vlastimil Babka
2020-06-23 6:13 ` [PATCH v3 6/8] mm/gup: use a standard migration target allocation callback js1304
2020-06-25 12:08 ` Michal Hocko
2020-06-26 5:03 ` Joonsoo Kim
2020-07-03 15:56 ` Vlastimil Babka
2020-07-06 8:34 ` Joonsoo Kim
2020-06-23 6:13 ` [PATCH v3 7/8] mm/mempolicy: " js1304
2020-06-25 12:09 ` Michal Hocko
2020-07-03 15:59 ` Vlastimil Babka
2020-07-08 1:20 ` Qian Cai
2020-07-08 6:45 ` Michal Hocko
2020-10-08 3:21 ` Hugh Dickins
2020-10-08 17:29 ` Mike Kravetz
2020-10-09 5:50 ` Hugh Dickins
2020-10-09 17:42 ` Mike Kravetz
2020-10-09 22:23 ` Hugh Dickins
2020-10-10 0:25 ` Mike Kravetz
2020-06-23 6:13 ` [PATCH v3 8/8] mm/page_alloc: remove a wrapper for alloc_migration_target() js1304
2020-06-25 12:10 ` Michal Hocko
2020-07-03 16:18 ` Vlastimil Babka
2020-07-06 8:44 ` Joonsoo Kim
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