struct list_head *src = &lruvec->lists[lru];
unsigned long nr_taken = 0;
unsigned long nr_zone_taken[MAX_NR_ZONES] = { 0 };
+ unsigned long nr_skipped[MAX_NR_ZONES] = { 0, };
unsigned long scan, nr_pages;
LIST_HEAD(pages_skipped);
if (page_zonenum(page) > sc->reclaim_idx) {
list_move(&page->lru, &pages_skipped);
+ nr_skipped[page_zonenum(page)]++;
continue;
}
* scanning would soon rescan the same pages to skip and put the
* system at risk of premature OOM.
*/
- if (!list_empty(&pages_skipped))
+ if (!list_empty(&pages_skipped)) {
+ int zid;
+
list_splice(&pages_skipped, src);
+ for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+ if (!nr_skipped[zid])
+ continue;
+
+ __count_zid_vm_events(PGSCAN_SKIP, zid, nr_skipped[zid]);
+ }
+ }
*nr_scanned = scan;
- trace_mm_vmscan_lru_isolate(sc->order, nr_to_scan, scan,
+ trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan, scan,
nr_taken, mode, is_file_lru(lru));
for (scan = 0; scan < MAX_NR_ZONES; scan++) {
nr_pages = nr_zone_taken[scan];
delayacct_freepages_start();
if (global_reclaim(sc))
- count_vm_event(ALLOCSTALL);
+ __count_zid_vm_events(ALLOCSTALL, sc->reclaim_idx, 1);
do {
vmpressure_prio(sc->gfp_mask, sc->target_mem_cgroup,
trace_mm_vmscan_direct_reclaim_begin(order,
sc.may_writepage,
- gfp_mask);
+ gfp_mask,
+ sc.reclaim_idx);
nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
trace_mm_vmscan_memcg_softlimit_reclaim_begin(sc.order,
sc.may_writepage,
- sc.gfp_mask);
+ sc.gfp_mask,
+ sc.reclaim_idx);
/*
* NOTE: Although we can get the priority field, using it
trace_mm_vmscan_memcg_reclaim_begin(0,
sc.may_writepage,
- sc.gfp_mask);
+ sc.gfp_mask,
+ sc.reclaim_idx);
nr_reclaimed = do_try_to_free_pages(zonelist, &sc);
*
* Returns true if kswapd is ready to sleep
*/
-static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
- int classzone_idx)
+static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, int classzone_idx)
{
int i;
- /* If a direct reclaimer woke kswapd within HZ/10, it's premature */
- if (remaining)
- return false;
-
/*
* The throttled processes are normally woken up in balance_pgdat() as
* soon as pfmemalloc_watermark_ok() is true. But there is a potential
.may_writepage = !laptop_mode,
.may_unmap = 1,
.may_swap = 1,
- .reclaim_idx = classzone_idx,
};
count_vm_event(PAGEOUTRUN);
bool raise_priority = true;
sc.nr_reclaimed = 0;
+ sc.reclaim_idx = classzone_idx;
/*
- * If the number of buffer_heads in the machine exceeds the
- * maximum allowed level then reclaim from all zones. This is
- * not specific to highmem as highmem may not exist but it is
- * it is expected that buffer_heads are stripped in writeback.
+ * If the number of buffer_heads exceeds the maximum allowed
+ * then consider reclaiming from all zones. This has a dual
+ * purpose -- on 64-bit systems it is expected that
+ * buffer_heads are stripped during active rotation. On 32-bit
+ * systems, highmem pages can pin lowmem memory and shrinking
+ * buffers can relieve lowmem pressure. Reclaim may still not
+ * go ahead if all eligible zones for the original allocation
+ * request are balanced to avoid excessive reclaim from kswapd.
*/
if (buffer_heads_over_limit) {
for (i = MAX_NR_ZONES - 1; i >= 0; i--) {
* Scanning from low to high zone would allow congestion to be
* cleared during a very small window when a small low
* zone was balanced even under extreme pressure when the
- * overall node may be congested.
+ * overall node may be congested. Note that sc.reclaim_idx
+ * is not used as buffer_heads_over_limit may have adjusted
+ * it.
*/
- for (i = sc.reclaim_idx; i >= 0; i--) {
+ for (i = classzone_idx; i >= 0; i--) {
zone = pgdat->node_zones + i;
if (!populated_zone(zone))
continue;
- if (zone_balanced(zone, sc.order, sc.reclaim_idx))
+ if (zone_balanced(zone, sc.order, classzone_idx))
goto out;
}
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
/* Try to sleep for a short interval */
- if (prepare_kswapd_sleep(pgdat, reclaim_order, remaining, classzone_idx)) {
+ if (prepare_kswapd_sleep(pgdat, reclaim_order, classzone_idx)) {
/*
* Compaction records what page blocks it recently failed to
* isolate pages from and skips them in the future scanning.
* After a short sleep, check if it was a premature sleep. If not, then
* go fully to sleep until explicitly woken up.
*/
- if (prepare_kswapd_sleep(pgdat, reclaim_order, remaining, classzone_idx)) {
+ if (!remaining &&
+ prepare_kswapd_sleep(pgdat, reclaim_order, classzone_idx)) {
trace_mm_vmscan_kswapd_sleep(pgdat->node_id);
/*
* but kcompactd is woken to compact for the original
* request (alloc_order).
*/
- trace_mm_vmscan_kswapd_wake(pgdat->node_id, alloc_order);
+ trace_mm_vmscan_kswapd_wake(pgdat->node_id, classzone_idx,
+ alloc_order);
reclaim_order = balance_pgdat(pgdat, alloc_order, classzone_idx);
if (reclaim_order < alloc_order)
goto kswapd_try_sleep;
projects / deliverable / linux.git / blobdiff