From: Mel Gorman <mgorman@suse.de>
To: "Huang, Ying" <ying.huang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>, Rik van Riel <riel@redhat.com>,
Ingo Molnar <mingo@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Fengguang Wu <fengguang.wu@intel.com>
Subject: Re: [RFC 01/10] autonuma: Fix watermark checking in migrate_balanced_pgdat()
Date: Fri, 1 Nov 2019 11:11:45 +0000 [thread overview]
Message-ID: <20191101111145.GN28938@suse.de> (raw)
In-Reply-To: <20191101075727.26683-2-ying.huang@intel.com>
On Fri, Nov 01, 2019 at 03:57:18PM +0800, Huang, Ying wrote:
> From: Huang Ying <ying.huang@intel.com>
>
> When zone_watermark_ok() is called in migrate_balanced_pgdat() to
> check migration target node, the parameter classzone_idx (for
> requested zone) is specified as 0 (ZONE_DMA). But when allocating
> memory for autonuma in alloc_misplaced_dst_page(), the requested zone
> from GFP flags is ZONE_MOVABLE. That is, the requested zone is
> different. The size of lowmem_reserve for the different requested
> zone is different. And this may cause some issues.
>
> For example, in the zoneinfo of a test machine as below,
>
> Node 0, zone DMA32
> pages free 61592
> min 29
> low 454
> high 879
> spanned 1044480
> present 442306
> managed 425921
> protection: (0, 0, 62457, 62457, 62457)
>
> The free page number of ZONE_DMA32 is greater than "high watermark +
> lowmem_reserve[ZONE_DMA]", but less than "high watermark +
> lowmem_reserve[ZONE_MOVABLE]". And because __alloc_pages_node() in
> alloc_misplaced_dst_page() requests ZONE_MOVABLE, the
> zone_watermark_ok() on ZONE_DMA32 in migrate_balanced_pgdat() may
> always return true. So, autonuma may not stop even when memory
> pressure in node 0 is heavy.
>
> To fix the issue, ZONE_MOVABLE is used as parameter to call
> zone_watermark_ok() in migrate_balanced_pgdat(). This makes it same
> as requested zone in alloc_misplaced_dst_page(). So that
> migrate_balanced_pgdat() returns false when memory pressure is heavy.
>
> Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Mel Gorman <mgorman@suse.de>
This patch is independent of the series and should be resent separately.
Alternatively Andrew, please pick this patch up on its own.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2019-11-01 11:11 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-01 7:57 [RFC 00/10] autonuma: Optimize memory placement in memory tiering system Huang, Ying
2019-11-01 7:57 ` [RFC 01/10] autonuma: Fix watermark checking in migrate_balanced_pgdat() Huang, Ying
2019-11-01 11:11 ` Mel Gorman [this message]
2019-11-01 7:57 ` [RFC 02/10] autonuma: Reduce cache footprint when scanning page tables Huang, Ying
2019-11-01 11:13 ` Mel Gorman
2019-11-01 7:57 ` [RFC 03/10] autonuma: Add NUMA_BALANCING_MEMORY_TIERING mode Huang, Ying
2019-11-01 7:57 ` [RFC 04/10] autonuma, memory tiering: Rate limit NUMA migration throughput Huang, Ying
2019-11-01 7:57 ` [RFC 05/10] autonuma, memory tiering: Use kswapd to demote cold pages to PMEM Huang, Ying
2019-11-01 7:57 ` [RFC 06/10] autonuma, memory tiering: Skip to scan fastest memory Huang, Ying
2019-11-01 7:57 ` [RFC 07/10] autonuma, memory tiering: Only promote page if accessed twice Huang, Ying
2019-11-01 7:57 ` [RFC 08/10] autonuma, memory tiering: Select hotter pages to promote to fast memory node Huang, Ying
2019-11-01 9:24 ` Peter Zijlstra
2019-11-04 2:41 ` Huang, Ying
2019-11-04 8:44 ` Peter Zijlstra
2019-11-04 10:13 ` Huang, Ying
2019-11-01 7:57 ` [RFC 09/10] autonuma, memory tiering: Double hot threshold for write hint page fault Huang, Ying
2019-11-01 7:57 ` [RFC 10/10] autonuma, memory tiering: Adjust hot threshold automatically Huang, Ying
2019-11-01 9:31 ` Peter Zijlstra
2019-11-04 6:11 ` Huang, Ying
2019-11-04 8:49 ` Peter Zijlstra
2019-11-04 10:12 ` Huang, Ying
2019-11-21 8:38 ` Huang, Ying
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