From: Oscar Salvador <osalvador@suse.de>
To: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@redhat.com>,
Muchun Song <songmuchun@bytedance.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 2/5] mm,compaction: Let isolate_migratepages_{range,block} return error codes
Date: Fri, 19 Mar 2021 10:57:47 +0100 [thread overview]
Message-ID: <20210319095742.GA6409@linux> (raw)
In-Reply-To: <YFM7VPo06EuzfN4b@dhcp22.suse.cz>
On Thu, Mar 18, 2021 at 12:36:52PM +0100, Michal Hocko wrote:
> Yeah, makes sense. I am not a fan of the above form of documentation.
> Btw. maybe renaming the field would be even better, both from the
> intention and review all existing users. I would go with pfn_iter or
> something that wouldn't make it sound like migration specific.
Just to be sure we are on the same page, you meant something like the following
(wrt. comments):
/*
* compact_control is used to track pages being migrated and the free pages
* they are being migrated to during memory compaction. The free_pfn starts
* at the end of a zone and migrate_pfn begins at the start. Movable pages
* are moved to the end of a zone during a compaction run and the run
* completes when free_pfn <= migrate_pfn
*
* freepages: List of free pages to migrate to
* migratepages: List of pages that need to be migrated
* nr_freepages: Number of isolated free pages
...
*/
struct compact_control {
struct list_head freepages;
...
With the preface that I am not really familiar with compaction code:
About renaming the variable to something else, I wouldn't do it.
I see migrate_pfn being used in contexts where migration gets mentioned,
e.g:
/*
* Briefly search the free lists for a migration source that already has
* some free pages to reduce the number of pages that need migration
* before a pageblock is free.
*/
fast_find_migrateblock(struct compact_control *cc)
{
...
unsigned long pfn = cc->migrate_pfn;
}
isolate_migratepages()
/* Record where migration scanner will be restarted. */
So, I would either stick with it, or add a new 'iter_pfn'/'next_pfn_scan'
field if we feel the need to.
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2021-03-19 9:58 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-17 11:12 [PATCH v5 0/5] Make alloc_contig_range handle Hugetlb pages Oscar Salvador
2021-03-17 11:12 ` [PATCH v5 1/5] mm,page_alloc: Bail out earlier on -ENOMEM in alloc_contig_migrate_range Oscar Salvador
2021-03-17 14:05 ` Michal Hocko
2021-03-17 14:42 ` David Hildenbrand
2021-03-17 14:49 ` Michal Hocko
2021-03-18 11:04 ` Oscar Salvador
2021-03-18 11:37 ` Michal Hocko
2021-03-17 11:12 ` [PATCH v5 2/5] mm,compaction: Let isolate_migratepages_{range,block} return error codes Oscar Salvador
2021-03-17 14:12 ` Michal Hocko
2021-03-17 14:38 ` Oscar Salvador
2021-03-17 14:59 ` Michal Hocko
2021-03-18 9:50 ` Vlastimil Babka
2021-03-18 10:22 ` Michal Hocko
2021-03-18 11:10 ` Vlastimil Babka
2021-03-18 11:36 ` Michal Hocko
2021-03-19 9:57 ` Oscar Salvador [this message]
2021-03-19 10:14 ` Vlastimil Babka
2021-03-19 10:26 ` Oscar Salvador
2021-03-17 11:12 ` [PATCH v5 3/5] mm: Make alloc_contig_range handle free hugetlb pages Oscar Salvador
2021-03-17 14:22 ` Michal Hocko
2021-03-17 11:12 ` [PATCH v5 4/5] mm: Make alloc_contig_range handle in-use " Oscar Salvador
2021-03-17 14:26 ` Michal Hocko
2021-03-18 8:54 ` Oscar Salvador
2021-03-18 9:29 ` Michal Hocko
2021-03-18 9:59 ` Oscar Salvador
2021-03-18 10:12 ` Michal Hocko
2021-03-17 11:12 ` [PATCH v5 5/5] mm,page_alloc: Drop unnecessary checks from pfn_range_valid_contig Oscar Salvador
2021-03-17 11:15 ` David Hildenbrand
2021-03-17 14:31 ` Michal Hocko
2021-03-17 14:36 ` David Hildenbrand
2021-03-17 15:03 ` Michal Hocko
2021-03-18 8:44 ` Oscar Salvador
2021-03-18 8:55 ` Michal Hocko
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=20210319095742.GA6409@linux \
--to=osalvador@suse.de \
--cc=akpm@linux-foundation.org \
--cc=david@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=mike.kravetz@oracle.com \
--cc=songmuchun@bytedance.com \
--cc=vbabka@suse.cz \
/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).