From: zhenwei pi Date: Tue, 23 Apr 2024 03:41:09 +0000 (+0800) Subject: virtio_balloon: introduce memory scan/reclaim info X-Git-Tag: v6.12-rc1~46^2~28 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=74c025c5d7e4ac7c7ad269c1ee64da4bdfe4770c;p=thirdparty%2Fkernel%2Flinux.git virtio_balloon: introduce memory scan/reclaim info 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. Acked-by: David Hildenbrand Signed-off-by: zhenwei pi Message-Id: <20240423034109.1552866-5-pizhenwei@bytedance.com> Signed-off-by: Michael S. Tsirkin --- diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 6f108b2977de0..b36d2803674ef 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -373,6 +373,15 @@ static inline unsigned int update_balloon_vm_stats(struct virtio_balloon *vb) 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]); diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h index 487b893a160ed..ee35a372805d4 100644 --- a/include/uapi/linux/virtio_balloon.h +++ b/include/uapi/linux/virtio_balloon.h @@ -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("")