From: Zi Yan <ziy@nvidia.com>
To: Huang Ying <ying.huang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Dave Hansen <dave.hansen@linux.intel.com>,
Yang Shi <shy828301@gmail.com>, Michal Hocko <mhocko@suse.com>,
Wei Xu <weixugc@google.com>, osalvador <osalvador@suse.de>,
David Rientjes <rientjes@google.com>,
Dan Williams <dan.j.williams@intel.com>,
David Hildenbrand <david@redhat.com>
Subject: Re: [PATCH -V10 2/9] mm/migrate: update node demotion order on hotplug events
Date: Thu, 15 Jul 2021 14:00:49 -0400 [thread overview]
Message-ID: <FDEEF381-7672-458B-949D-9F5D8D9003B5@nvidia.com> (raw)
In-Reply-To: <20210715055145.195411-3-ying.huang@intel.com>
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On 15 Jul 2021, at 1:51, Huang Ying wrote:
> From: Dave Hansen <dave.hansen@linux.intel.com>
>
> Reclaim-based migration is attempting to optimize data placement in
> memory based on the system topology. If the system changes, so must
> the migration ordering.
>
> The implementation is conceptually simple and entirely unoptimized.
> On any memory or CPU hotplug events, assume that a node was added or
> removed and recalculate all migration targets. This ensures that the
> node_demotion[] array is always ready to be used in case the new
> reclaim mode is enabled.
>
> This recalculation is far from optimal, most glaringly that it does
> not even attempt to figure out the hotplug event would have some
> *actual* effect on the demotion order. But, given the expected
> paucity of hotplug events, this should be fine.
>
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
> Reviewed-by: Yang Shi <shy828301@gmail.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Wei Xu <weixugc@google.com>
> Cc: Zi Yan <ziy@nvidia.com>
> Cc: osalvador <osalvador@suse.de>
> Cc: David Rientjes <rientjes@google.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: David Hildenbrand <david@redhat.com>
>
> --
>
> Changes since 20210618:
> * moved RCU part to the prev patch in series.
>
> Changes since 20210302:
> * remove duplicate synchronize_rcu()
> ---
> mm/migrate.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 89 insertions(+), 1 deletion(-)
LGTM. Reviewed-by: Zi Yan <ziy@nvidia.com>
—
Best Regards,
Yan, Zi
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next prev parent reply other threads:[~2021-07-15 18:02 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-15 5:51 [PATCH -V10 0/9] Migrate Pages in lieu of discard Huang Ying
2021-07-15 5:51 ` [PATCH -V10 1/9] mm/numa: automatically generate node migration order Huang Ying
2021-07-15 17:52 ` Zi Yan
2021-07-15 5:51 ` [PATCH -V10 2/9] mm/migrate: update node demotion order on hotplug events Huang Ying
2021-07-15 18:00 ` Zi Yan [this message]
2021-07-15 5:51 ` [PATCH -V10 3/9] mm/migrate: enable returning precise migrate_pages() success count Huang Ying
2021-07-15 18:02 ` Zi Yan
2021-07-15 5:51 ` [PATCH -V10 4/9] mm/migrate: demote pages during reclaim Huang Ying
2021-07-15 5:51 ` [PATCH -V10 5/9] mm/vmscan: add page demotion counter Huang Ying
2021-07-15 5:51 ` [PATCH -V10 6/9] mm/vmscan: add helper for querying ability to age anonymous pages Huang Ying
2021-07-15 5:51 ` [PATCH -V10 7/9] mm/vmscan: Consider anonymous pages without swap Huang Ying
2021-07-15 5:51 ` [PATCH -V10 8/9] mm/vmscan: never demote for memcg reclaim Huang Ying
2021-07-15 5:51 ` [PATCH -V10 9/9] mm/migrate: add sysfs interface to enable reclaim migration Huang Ying
2021-07-15 19:38 ` [PATCH -V10 0/9] Migrate Pages in lieu of discard Andrew Morton
2021-07-15 21:42 ` Dave Hansen
2021-07-16 1:10 ` Matthew Wilcox
2021-07-16 3:32 ` Huang, Ying
2021-07-16 3:54 ` Andrew Morton
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