The patch titled
memcg: check memcg dirty limits in page writeback
has been added to the -mm tree. Its filename is
memcg-check-memcg-dirty-limits-in-page-writeback.patch
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------------------------------------------------------
Subject: memcg: check memcg dirty limits in page writeback
From: Greg Thelen <gthelen@xxxxxxxxxx>
If the current process is in a non-root memcg, then balance_dirty_pages()
will consider the memcg dirty limits as well as the system-wide limits.
This allows different cgroups to have distinct dirty limits which trigger
direct and background writeback at different levels.
If called with a mem_cgroup, then throttle_vm_writeout() queries the given
cgroup for its dirty memory usage limits.
Signed-off-by: Andrea Righi <arighi@xxxxxxxxxxx>
Signed-off-by: Greg Thelen <gthelen@xxxxxxxxxx>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Acked-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Cc: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Chad Talbott <ctalbott@xxxxxxxxxx>
Cc: Justin TerAvest <teravest@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/writeback.h | 3 ++-
mm/page-writeback.c | 32 +++++++++++++++++++++++++++-----
mm/vmscan.c | 2 +-
3 files changed, 30 insertions(+), 7 deletions(-)
diff -puN include/linux/writeback.h~memcg-check-memcg-dirty-limits-in-page-writeback include/linux/writeback.h
--- a/include/linux/writeback.h~memcg-check-memcg-dirty-limits-in-page-writeback
+++ a/include/linux/writeback.h
@@ -8,6 +8,7 @@
#include <linux/fs.h>
struct backing_dev_info;
+struct mem_cgroup;
extern spinlock_t inode_lock;
@@ -92,7 +93,7 @@ void laptop_mode_timer_fn(unsigned long
#else
static inline void laptop_sync_completion(void) { }
#endif
-void throttle_vm_writeout(gfp_t gfp_mask);
+void throttle_vm_writeout(gfp_t gfp_mask, struct mem_cgroup *mem_cgroup);
/* These are exported to sysctl. */
extern int dirty_background_ratio;
diff -puN mm/page-writeback.c~memcg-check-memcg-dirty-limits-in-page-writeback mm/page-writeback.c
--- a/mm/page-writeback.c~memcg-check-memcg-dirty-limits-in-page-writeback
+++ a/mm/page-writeback.c
@@ -473,7 +473,8 @@ unsigned long bdi_dirty_limit(struct bac
* data. It looks at the number of dirty pages in the machine and will force
* the caller to perform writeback if the system is over `vm_dirty_ratio'.
* If we're over `background_thresh' then the writeback threads are woken to
- * perform some writeout.
+ * perform some writeout. The current task may have per-memcg dirty
+ * limits, which are also checked.
*/
static void balance_dirty_pages(struct address_space *mapping,
unsigned long write_chunk)
@@ -488,6 +489,8 @@ static void balance_dirty_pages(struct a
bool dirty_exceeded = false;
struct backing_dev_info *bdi = mapping->backing_dev_info;
+ mem_cgroup_balance_dirty_pages(mapping, write_chunk);
+
for (;;) {
struct writeback_control wbc = {
.sync_mode = WB_SYNC_NONE,
@@ -651,23 +654,42 @@ void balance_dirty_pages_ratelimited_nr(
}
EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr);
-void throttle_vm_writeout(gfp_t gfp_mask)
+/*
+ * Throttle the current task if it is near dirty memory usage limits. Both
+ * global dirty memory limits and (if @mem_cgroup is given) per-cgroup dirty
+ * memory limits are checked.
+ *
+ * If near limits, then wait for usage to drop. Dirty usage should drop because
+ * dirty producers should have used balance_dirty_pages(), which would have
+ * scheduled writeback.
+ */
+void throttle_vm_writeout(gfp_t gfp_mask, struct mem_cgroup *mem_cgroup)
{
unsigned long background_thresh;
unsigned long dirty_thresh;
+ struct dirty_info memcg_info;
+ bool do_memcg;
for ( ; ; ) {
global_dirty_limits(&background_thresh, &dirty_thresh);
+ do_memcg = mem_cgroup && mem_cgroup_hierarchical_dirty_info(
+ determine_dirtyable_memory(), true, mem_cgroup,
+ &memcg_info);
/*
* Boost the allowable dirty threshold a bit for page
* allocators so they don't get DoS'ed by heavy writers
*/
dirty_thresh += dirty_thresh / 10; /* wheeee... */
+ if (do_memcg)
+ memcg_info.dirty_thresh += memcg_info.dirty_thresh / 10;
- if (global_page_state(NR_UNSTABLE_NFS) +
- global_page_state(NR_WRITEBACK) <= dirty_thresh)
- break;
+ if ((global_page_state(NR_UNSTABLE_NFS) +
+ global_page_state(NR_WRITEBACK) <= dirty_thresh) &&
+ (!do_memcg ||
+ (memcg_info.nr_unstable_nfs +
+ memcg_info.nr_writeback <= memcg_info.dirty_thresh)))
+ break;
congestion_wait(BLK_RW_ASYNC, HZ/10);
/*
diff -puN mm/vmscan.c~memcg-check-memcg-dirty-limits-in-page-writeback mm/vmscan.c
--- a/mm/vmscan.c~memcg-check-memcg-dirty-limits-in-page-writeback
+++ a/mm/vmscan.c
@@ -1939,7 +1939,7 @@ restart:
sc->nr_scanned - nr_scanned, sc))
goto restart;
- throttle_vm_writeout(sc->gfp_mask);
+ throttle_vm_writeout(sc->gfp_mask, sc->mem_cgroup);
}
/*
_
Patches currently in -mm which might be from gthelen@xxxxxxxxxx are
linux-next.patch
memcg-res_counter_read_u64-fix-potential-races-on-32-bit-machines.patch
memcg-break-out-event-counters-from-other-stats.patch
memcg-use-native-word-page-statistics-counters.patch
mm-memcontrolc-suppress-uninitializer-var-warning-with-older-gccs.patch
memcg-document-cgroup-dirty-memory-interfaces.patch
memcg-add-page_cgroup-flags-for-dirty-page-tracking.patch
memcg-add-dirty-page-accounting-infrastructure.patch
memcg-add-kernel-calls-for-memcg-dirty-page-stats.patch
memcg-add-dirty-limits-to-mem_cgroup.patch
memcg-add-cgroupfs-interface-to-memcg-dirty-limits.patch
memcg-add-dirty-limiting-routines.patch
memcg-check-memcg-dirty-limits-in-page-writeback.patch
memcg-make-background-writeback-memcg-aware.patch
--
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