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From:   Nitin Gupta <ngupta@nitingupta.dev>
Date:   Tue, 9 Jun 2020 11:37:31 -0700
Message-ID: <CAB6CXpAGTWGNboAXEkqC2wZsHmvbhFf_5enguXJ7QssRpr=c9A@mail.gmail.com>
Subject: Re: [PATCH v6] mm: Proactive compaction
To:     Vlastimil Babka <vbabka@suse.cz>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Mel Gorman <mgorman@techsingularity.net>,
        Michal Hocko <mhocko@suse.com>,
        Nitin Gupta <nigupta@nvidia.com>,
        Matthew Wilcox <willy@infradead.org>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        David Rientjes <rientjes@google.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>,
        Linux API <linux-api@vger.kernel.org>,
        Khalid Aziz <khalid.aziz@oracle.com>
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On Mon, Jun 1, 2020 at 12:48 PM Nitin Gupta <nigupta@nvidia.com> wrote:
>
> For some applications, we need to allocate almost all memory as
> hugepages. However, on a running system, higher-order allocations can
> fail if the memory is fragmented. Linux kernel currently does on-demand
> compaction as we request more hugepages, but this style of compaction
> incurs very high latency. Experiments with one-time full memory
> compaction (followed by hugepage allocations) show that kernel is able
> to restore a highly fragmented memory state to a fairly compacted memory
> state within <1 sec for a 32G system. Such data suggests that a more
> proactive compaction can help us allocate a large fraction of memory as
> hugepages keeping allocation latencies low.
>

> Signed-off-by: Nitin Gupta <nigupta@nvidia.com>
> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>

(+CC Khalid)

Can this be pipelined for upstream inclusion now? Sorry, I'm a bit
rusty on upstream flow these days.

Thanks,
Nitin