vmscan: add shrink_slab tracepoints
It is impossible to understand what the shrinkers are actually doing
without instrumenting the code, so add a some tracepoints to allow
insight to be gained.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index b2c33bd..36851f7 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -179,6 +179,83 @@
TP_ARGS(nr_reclaimed)
);
+TRACE_EVENT(mm_shrink_slab_start,
+ TP_PROTO(struct shrinker *shr, struct shrink_control *sc,
+ long nr_objects_to_shrink, unsigned long pgs_scanned,
+ unsigned long lru_pgs, unsigned long cache_items,
+ unsigned long long delta, unsigned long total_scan),
+
+ TP_ARGS(shr, sc, nr_objects_to_shrink, pgs_scanned, lru_pgs,
+ cache_items, delta, total_scan),
+
+ TP_STRUCT__entry(
+ __field(struct shrinker *, shr)
+ __field(void *, shrink)
+ __field(long, nr_objects_to_shrink)
+ __field(gfp_t, gfp_flags)
+ __field(unsigned long, pgs_scanned)
+ __field(unsigned long, lru_pgs)
+ __field(unsigned long, cache_items)
+ __field(unsigned long long, delta)
+ __field(unsigned long, total_scan)
+ ),
+
+ TP_fast_assign(
+ __entry->shr = shr;
+ __entry->shrink = shr->shrink;
+ __entry->nr_objects_to_shrink = nr_objects_to_shrink;
+ __entry->gfp_flags = sc->gfp_mask;
+ __entry->pgs_scanned = pgs_scanned;
+ __entry->lru_pgs = lru_pgs;
+ __entry->cache_items = cache_items;
+ __entry->delta = delta;
+ __entry->total_scan = total_scan;
+ ),
+
+ TP_printk("%pF %p: objects to shrink %ld gfp_flags %s pgs_scanned %ld lru_pgs %ld cache items %ld delta %lld total_scan %ld",
+ __entry->shrink,
+ __entry->shr,
+ __entry->nr_objects_to_shrink,
+ show_gfp_flags(__entry->gfp_flags),
+ __entry->pgs_scanned,
+ __entry->lru_pgs,
+ __entry->cache_items,
+ __entry->delta,
+ __entry->total_scan)
+);
+
+TRACE_EVENT(mm_shrink_slab_end,
+ TP_PROTO(struct shrinker *shr, int shrinker_retval,
+ long unused_scan_cnt, long new_scan_cnt),
+
+ TP_ARGS(shr, shrinker_retval, unused_scan_cnt, new_scan_cnt),
+
+ TP_STRUCT__entry(
+ __field(struct shrinker *, shr)
+ __field(void *, shrink)
+ __field(long, unused_scan)
+ __field(long, new_scan)
+ __field(int, retval)
+ __field(long, total_scan)
+ ),
+
+ TP_fast_assign(
+ __entry->shr = shr;
+ __entry->shrink = shr->shrink;
+ __entry->unused_scan = unused_scan_cnt;
+ __entry->new_scan = new_scan_cnt;
+ __entry->retval = shrinker_retval;
+ __entry->total_scan = new_scan_cnt - unused_scan_cnt;
+ ),
+
+ TP_printk("%pF %p: unused scan count %ld new scan count %ld total_scan %ld last shrinker return val %d",
+ __entry->shrink,
+ __entry->shr,
+ __entry->unused_scan,
+ __entry->new_scan,
+ __entry->total_scan,
+ __entry->retval)
+);
DECLARE_EVENT_CLASS(mm_vmscan_lru_isolate_template,