Subject: [merged] mm-numa-limit-scope-of-lock-for-numa-migrate-rate-limiting.patch removed from -mm tree
To: mgorman@xxxxxxx,athorlton@xxxxxxx,riel@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Wed, 22 Jan 2014 12:14:40 -0800
The patch titled
Subject: mm: numa: limit scope of lock for NUMA migrate rate limiting
has been removed from the -mm tree. Its filename was
mm-numa-limit-scope-of-lock-for-numa-migrate-rate-limiting.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxx>
Subject: mm: numa: limit scope of lock for NUMA migrate rate limiting
NUMA migrate rate limiting protects a migration counter and window using a
lock but in some cases this can be a contended lock. It is not critical
that the number of pages be perfect, lost updates are acceptable. Reduce
the importance of this lock.
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>
Cc: Alex Thorlton <athorlton@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mmzone.h | 5 +----
mm/migrate.c | 21 ++++++++++++---------
2 files changed, 13 insertions(+), 13 deletions(-)
diff -puN include/linux/mmzone.h~mm-numa-limit-scope-of-lock-for-numa-migrate-rate-limiting include/linux/mmzone.h
--- a/include/linux/mmzone.h~mm-numa-limit-scope-of-lock-for-numa-migrate-rate-limiting
+++ a/include/linux/mmzone.h
@@ -764,10 +764,7 @@ typedef struct pglist_data {
int kswapd_max_order;
enum zone_type classzone_idx;
#ifdef CONFIG_NUMA_BALANCING
- /*
- * Lock serializing the per destination node AutoNUMA memory
- * migration rate limiting data.
- */
+ /* Lock serializing the migrate rate limiting window */
spinlock_t numabalancing_migrate_lock;
/* Rate limiting time interval */
diff -puN mm/migrate.c~mm-numa-limit-scope-of-lock-for-numa-migrate-rate-limiting mm/migrate.c
--- a/mm/migrate.c~mm-numa-limit-scope-of-lock-for-numa-migrate-rate-limiting
+++ a/mm/migrate.c
@@ -1602,26 +1602,29 @@ bool migrate_ratelimited(int node)
static bool numamigrate_update_ratelimit(pg_data_t *pgdat,
unsigned long nr_pages)
{
- bool rate_limited = false;
-
/*
* Rate-limit the amount of data that is being migrated to a node.
* Optimal placement is no good if the memory bus is saturated and
* all the time is being spent migrating!
*/
- spin_lock(&pgdat->numabalancing_migrate_lock);
if (time_after(jiffies, pgdat->numabalancing_migrate_next_window)) {
+ spin_lock(&pgdat->numabalancing_migrate_lock);
pgdat->numabalancing_migrate_nr_pages = 0;
pgdat->numabalancing_migrate_next_window = jiffies +
msecs_to_jiffies(migrate_interval_millisecs);
+ spin_unlock(&pgdat->numabalancing_migrate_lock);
}
if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages)
- rate_limited = true;
- else
- pgdat->numabalancing_migrate_nr_pages += nr_pages;
- spin_unlock(&pgdat->numabalancing_migrate_lock);
-
- return rate_limited;
+ return true;
+
+ /*
+ * This is an unlocked non-atomic update so errors are possible.
+ * The consequences are failing to migrate when we potentiall should
+ * have which is not severe enough to warrant locking. If it is ever
+ * a problem, it can be converted to a per-cpu counter.
+ */
+ pgdat->numabalancing_migrate_nr_pages += nr_pages;
+ return false;
}
static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
_
Patches currently in -mm which might be from mgorman@xxxxxxx are
origin.patch
mm-remove-bug_on-from-mlock_vma_page.patch
x86-mm-account-for-tlb-flushes-only-when-debugging.patch
x86-mm-clean-up-inconsistencies-when-flushing-tlb-ranges.patch
x86-mm-eliminate-redundant-page-table-walk-during-tlb-range-flushing.patch
x86-mm-change-tlb_flushall_shift-for-ivybridge.patch
mm-x86-revisit-tlb_flushall_shift-tuning-for-page-flushes-except-on-ivybridge.patch
mm-page_alloc-allow-__gfp_nofail-to-allocate-below-watermarks-after-reclaim.patch
mm-munlock-fix-potential-race-with-thp-page-split.patch
numa-add-a-sysctl-for-numa_balancing.patch
numa-add-a-sysctl-for-numa_balancing-fix.patch
mm-vmscan-shrink-all-slab-objects-if-tight-on-memory.patch
mm-vmscan-call-numa-unaware-shrinkers-irrespective-of-nodemask.patch
mm-vmscan-respect-numa-policy-mask-when-shrinking-slab-on-direct-reclaim.patch
mm-vmscan-move-call-to-shrink_slab-to-shrink_zones.patch
mm-vmscan-remove-shrink_control-arg-from-do_try_to_free_pages.patch
mm-show-message-when-updating-min_free_kbytes-in-thp.patch
mm-improve-documentation-of-page_order-v2.patch
mm-improve-documentation-of-page_order-v2-fix.patch
linux-next.patch
mm-migratec-fix-setting-of-cpupid-on-page-migration-twice-against-normal-page.patch
zsmalloc-move-it-under-mm.patch
zram-promote-zram-from-staging.patch
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