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-rw-r--r--include/trace/events/vmscan.h12
-rw-r--r--mm/vmscan.c85
2 files changed, 14 insertions, 83 deletions
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index bdaf32f8a874..82f693395ac5 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -13,7 +13,7 @@
#define RECLAIM_WB_ANON 0x0001u
#define RECLAIM_WB_FILE 0x0002u
#define RECLAIM_WB_MIXED 0x0010u
-#define RECLAIM_WB_SYNC 0x0004u
+#define RECLAIM_WB_SYNC 0x0004u /* Unused, all reclaim async */
#define RECLAIM_WB_ASYNC 0x0008u
#define show_reclaim_flags(flags) \
@@ -27,13 +27,13 @@
#define trace_reclaim_flags(page, sync) ( \
(page_is_file_cache(page) ? RECLAIM_WB_FILE : RECLAIM_WB_ANON) | \
- (sync & RECLAIM_MODE_SYNC ? RECLAIM_WB_SYNC : RECLAIM_WB_ASYNC) \
+ (RECLAIM_WB_ASYNC) \
)
-#define trace_shrink_flags(file, sync) ( \
- (sync & RECLAIM_MODE_SYNC ? RECLAIM_WB_MIXED : \
- (file ? RECLAIM_WB_FILE : RECLAIM_WB_ANON)) | \
- (sync & RECLAIM_MODE_SYNC ? RECLAIM_WB_SYNC : RECLAIM_WB_ASYNC) \
+#define trace_shrink_flags(file, sync) \
+ ( \
+ (file ? RECLAIM_WB_FILE : RECLAIM_WB_ANON) | \
+ (RECLAIM_WB_ASYNC) \
)
TRACE_EVENT(mm_vmscan_kswapd_sleep,
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 546d02ce90ee..e27f27d4cc19 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -56,15 +56,11 @@
/*
* reclaim_mode determines how the inactive list is shrunk
* RECLAIM_MODE_SINGLE: Reclaim only order-0 pages
- * RECLAIM_MODE_ASYNC: Do not block
- * RECLAIM_MODE_SYNC: Allow blocking e.g. call wait_on_page_writeback
* RECLAIM_MODE_COMPACTION: For high-order allocations, reclaim a number of
* order-0 pages and then compact the zone
*/
typedef unsigned __bitwise__ reclaim_mode_t;
#define RECLAIM_MODE_SINGLE ((__force reclaim_mode_t)0x01u)
-#define RECLAIM_MODE_ASYNC ((__force reclaim_mode_t)0x02u)
-#define RECLAIM_MODE_SYNC ((__force reclaim_mode_t)0x04u)
#define RECLAIM_MODE_COMPACTION ((__force reclaim_mode_t)0x10u)
struct scan_control {
@@ -360,12 +356,8 @@ out:
return ret;
}
-static void set_reclaim_mode(int priority, struct scan_control *sc,
- bool sync)
+static void set_reclaim_mode(int priority, struct scan_control *sc)
{
- /* Sync reclaim used only for compaction */
- reclaim_mode_t syncmode = sync ? RECLAIM_MODE_SYNC : RECLAIM_MODE_ASYNC;
-
/*
* Restrict reclaim/compaction to costly allocations or when
* under memory pressure
@@ -373,14 +365,14 @@ static void set_reclaim_mode(int priority, struct scan_control *sc,
if (COMPACTION_BUILD && sc->order &&
(sc->order > PAGE_ALLOC_COSTLY_ORDER ||
priority < DEF_PRIORITY - 2))
- sc->reclaim_mode = RECLAIM_MODE_COMPACTION | syncmode;
+ sc->reclaim_mode = RECLAIM_MODE_COMPACTION;
else
- sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC;
+ sc->reclaim_mode = RECLAIM_MODE_SINGLE;
}
static void reset_reclaim_mode(struct scan_control *sc)
{
- sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC;
+ sc->reclaim_mode = RECLAIM_MODE_SINGLE;
}
static inline int is_page_cache_freeable(struct page *page)
@@ -791,19 +783,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
if (PageWriteback(page)) {
nr_writeback++;
- /*
- * Synchronous reclaim cannot queue pages for
- * writeback due to the possibility of stack overflow
- * but if it encounters a page under writeback, wait
- * for the IO to complete.
- */
- if ((sc->reclaim_mode & RECLAIM_MODE_SYNC) &&
- may_enter_fs)
- wait_on_page_writeback(page);
- else {
- unlock_page(page);
- goto keep_reclaim_mode;
- }
+ unlock_page(page);
+ goto keep;
}
references = page_check_references(page, mz, sc);
@@ -886,7 +867,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
goto activate_locked;
case PAGE_SUCCESS:
if (PageWriteback(page))
- goto keep_reclaim_mode;
+ goto keep;
if (PageDirty(page))
goto keep;
@@ -985,8 +966,6 @@ activate_locked:
keep_locked:
unlock_page(page);
keep:
- reset_reclaim_mode(sc);
-keep_reclaim_mode:
list_add(&page->lru, &ret_pages);
VM_BUG_ON(PageLRU(page) || PageUnevictable(page));
}
@@ -1342,47 +1321,6 @@ update_isolated_counts(struct mem_cgroup_zone *mz,
}
/*
- * Returns true if a direct reclaim should wait on pages under writeback.
- *
- * If we are direct reclaiming for contiguous pages and we do not reclaim
- * everything in the list, try again and wait for writeback IO to complete.
- * This will stall high-order allocations noticeably. Only do that when really
- * need to free the pages under high memory pressure.
- */
-static inline bool should_reclaim_stall(unsigned long nr_taken,
- unsigned long nr_freed,
- int priority,
- struct scan_control *sc)
-{
- int stall_priority;
-
- /* kswapd should not stall on sync IO */
- if (current_is_kswapd())
- return false;
-
- /* Only stall for memory compaction */
- if (sc->reclaim_mode & RECLAIM_MODE_SINGLE)
- return false;
-
- /* If we have reclaimed everything on the isolated list, no stall */
- if (nr_freed == nr_taken)
- return false;
-
- /*
- * For high-order allocations, there are two stall thresholds.
- * High-cost allocations stall immediately where as lower
- * order allocations such as stacks require the scanning
- * priority to be much higher before stalling.
- */
- if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
- stall_priority = DEF_PRIORITY;
- else
- stall_priority = DEF_PRIORITY / 3;
-
- return priority <= stall_priority;
-}
-
-/*
* shrink_inactive_list() is a helper for shrink_zone(). It returns the number
* of reclaimed pages
*/
@@ -1410,7 +1348,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
return SWAP_CLUSTER_MAX;
}
- set_reclaim_mode(priority, sc, false);
+ set_reclaim_mode(priority, sc);
lru_add_drain();
@@ -1442,13 +1380,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
nr_reclaimed = shrink_page_list(&page_list, mz, sc, priority,
&nr_dirty, &nr_writeback);
- /* Check if we should syncronously wait for writeback */
- if (should_reclaim_stall(nr_taken, nr_reclaimed, priority, sc)) {
- set_reclaim_mode(priority, sc, true);
- nr_reclaimed += shrink_page_list(&page_list, mz, sc,
- priority, &nr_dirty, &nr_writeback);
- }
-
spin_lock_irq(&zone->lru_lock);
reclaim_stat->recent_scanned[0] += nr_anon;