@@ -356,6 +356,15 @@ static unsigned int update_balloon_stats(struct virtio_balloon *vb)
stall += events[ALLOCSTALL_MOVABLE];
update_stat(vb, idx++, VIRTIO_BALLOON_S_ALLOC_STALL, stall);
+ update_stat(vb, idx++, VIRTIO_BALLOON_S_ASYNC_SCAN,
+ pages_to_bytes(events[PGSCAN_KSWAPD]));
+ update_stat(vb, idx++, VIRTIO_BALLOON_S_DIRECT_SCAN,
+ pages_to_bytes(events[PGSCAN_DIRECT]));
+ update_stat(vb, idx++, VIRTIO_BALLOON_S_ASYNC_RECLAIM,
+ pages_to_bytes(events[PGSTEAL_KSWAPD]));
+ update_stat(vb, idx++, VIRTIO_BALLOON_S_DIRECT_RECLAIM,
+ pages_to_bytes(events[PGSTEAL_DIRECT]));
+
#ifdef CONFIG_HUGETLB_PAGE
update_stat(vb, idx++, VIRTIO_BALLOON_S_HTLB_PGALLOC,
events[HTLB_BUDDY_PGALLOC]);
@@ -73,7 +73,11 @@ struct virtio_balloon_config {
#define VIRTIO_BALLOON_S_HTLB_PGFAIL 9 /* Hugetlb page allocation failures */
#define VIRTIO_BALLOON_S_OOM_KILL 10 /* OOM killer invocations */
#define VIRTIO_BALLOON_S_ALLOC_STALL 11 /* Stall count of memory allocatoin */
-#define VIRTIO_BALLOON_S_NR 12
+#define VIRTIO_BALLOON_S_ASYNC_SCAN 12 /* Amount of memory scanned asynchronously */
+#define VIRTIO_BALLOON_S_DIRECT_SCAN 13 /* Amount of memory scanned directly */
+#define VIRTIO_BALLOON_S_ASYNC_RECLAIM 14 /* Amount of memory reclaimed asynchronously */
+#define VIRTIO_BALLOON_S_DIRECT_RECLAIM 15 /* Amount of memory reclaimed directly */
+#define VIRTIO_BALLOON_S_NR 16
#define VIRTIO_BALLOON_S_NAMES_WITH_PREFIX(VIRTIO_BALLOON_S_NAMES_prefix) { \
VIRTIO_BALLOON_S_NAMES_prefix "swap-in", \
@@ -87,7 +91,11 @@ struct virtio_balloon_config {
VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-allocations", \
VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-failures", \
VIRTIO_BALLOON_S_NAMES_prefix "oom-kills", \
- VIRTIO_BALLOON_S_NAMES_prefix "alloc-stalls" \
+ VIRTIO_BALLOON_S_NAMES_prefix "alloc-stalls", \
+ VIRTIO_BALLOON_S_NAMES_prefix "async-scans", \
+ VIRTIO_BALLOON_S_NAMES_prefix "direct-scans", \
+ VIRTIO_BALLOON_S_NAMES_prefix "async-reclaims", \
+ VIRTIO_BALLOON_S_NAMES_prefix "direct-reclaims" \
}
#define VIRTIO_BALLOON_S_NAMES VIRTIO_BALLOON_S_NAMES_WITH_PREFIX("")
Expose memory scan/reclaim information to the host side via virtio balloon device. Now we have a metric to analyze the memory performance: y: counter increases n: counter does not changes h: the rate of counter change is high l: the rate of counter change is low OOM: VIRTIO_BALLOON_S_OOM_KILL STALL: VIRTIO_BALLOON_S_ALLOC_STALL ASCAN: VIRTIO_BALLOON_S_SCAN_ASYNC DSCAN: VIRTIO_BALLOON_S_SCAN_DIRECT ARCLM: VIRTIO_BALLOON_S_RECLAIM_ASYNC DRCLM: VIRTIO_BALLOON_S_RECLAIM_DIRECT - OOM[y], STALL[*], ASCAN[*], DSCAN[*], ARCLM[*], DRCLM[*]: the guest runs under really critial memory pressure - OOM[n], STALL[h], ASCAN[*], DSCAN[l], ARCLM[*], DRCLM[l]: the memory allocation stalls due to cgroup, not the global memory pressure. - OOM[n], STALL[h], ASCAN[*], DSCAN[h], ARCLM[*], DRCLM[h]: the memory allocation stalls due to global memory pressure. The performance gets hurt a lot. A high ratio between DRCLM/DSCAN shows quite effective memory reclaiming. - OOM[n], STALL[h], ASCAN[*], DSCAN[h], ARCLM[*], DRCLM[l]: the memory allocation stalls due to global memory pressure. the ratio between DRCLM/DSCAN gets low, the guest OS is thrashing heavily, the serious case leads poor performance and difficult trouble shooting. Ex, sshd may block on memory allocation when accepting new connections, a user can't login a VM by ssh command. - OOM[n], STALL[n], ASCAN[h], DSCAN[n], ARCLM[l], DRCLM[n]: the low ratio between ARCLM/ASCAN shows that the guest tries to reclaim more memory, but it can't. Once more memory is required in future, it will struggle to reclaim memory. Signed-off-by: zhenwei pi <pizhenwei@bytedance.com> --- drivers/virtio/virtio_balloon.c | 9 +++++++++ include/uapi/linux/virtio_balloon.h | 12 ++++++++++-- 2 files changed, 19 insertions(+), 2 deletions(-)