NFSD: Report the number of items evicted by the LRU walk

[ Upstream commit 94660cc19c75083af046b0f8362e3d3bc2eba21d ]

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 1d94491e5ddadb66190cd432242a1f06e85c1746..e5bd9f06492c8f5630e7c74fd57e564af099917c 100644 (file)
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -45,6 +45,7 @@ static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits);
 static DEFINE_PER_CPU(unsigned long, nfsd_file_acquisitions);
 static DEFINE_PER_CPU(unsigned long, nfsd_file_releases);
 static DEFINE_PER_CPU(unsigned long, nfsd_file_total_age);
+static DEFINE_PER_CPU(unsigned long, nfsd_file_evictions);
 
 struct nfsd_fcache_disposal {
        struct work_struct work;
@@ -445,6 +446,7 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru,
                goto out_skip;
 
        list_lru_isolate_move(lru, &nf->nf_lru, head);
+       this_cpu_inc(nfsd_file_evictions);
        return LRU_REMOVED;
 out_skip:
        return LRU_SKIP;
@@ -475,9 +477,11 @@ static void
 nfsd_file_gc(void)
 {
        LIST_HEAD(dispose);
+       unsigned long ret;
 
-       list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb,
-                     &dispose, LONG_MAX);
+       ret = list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb,
+                           &dispose, LONG_MAX);
+       trace_nfsd_file_gc_removed(ret, list_lru_count(&nfsd_file_lru));
        nfsd_file_gc_dispose_list(&dispose);
 }
 
@@ -502,6 +506,7 @@ nfsd_file_lru_scan(struct shrinker *s, struct shrink_control *sc)
 
        ret = list_lru_shrink_walk(&nfsd_file_lru, sc,
                                   nfsd_file_lru_cb, &dispose);
+       trace_nfsd_file_shrinker_removed(ret, list_lru_count(&nfsd_file_lru));
        nfsd_file_gc_dispose_list(&dispose);
        return ret;
 }
@@ -1064,7 +1069,7 @@ nfsd_file_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
  */
 static int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
 {
-       unsigned long hits = 0, acquisitions = 0, releases = 0;
+       unsigned long hits = 0, acquisitions = 0, releases = 0, evictions = 0;
        unsigned int i, count = 0, longest = 0;
        unsigned long lru = 0, total_age = 0;
 
@@ -1088,6 +1093,7 @@ static int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
                acquisitions += per_cpu(nfsd_file_acquisitions, i);
                releases += per_cpu(nfsd_file_releases, i);
                total_age += per_cpu(nfsd_file_total_age, i);
+               evictions += per_cpu(nfsd_file_evictions, i);
        }
 
        seq_printf(m, "total entries: %u\n", count);
@@ -1096,6 +1102,7 @@ static int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
        seq_printf(m, "cache hits:    %lu\n", hits);
        seq_printf(m, "acquisitions:  %lu\n", acquisitions);
        seq_printf(m, "releases:      %lu\n", releases);
+       seq_printf(m, "evictions:     %lu\n", evictions);
        if (releases)
                seq_printf(m, "mean age (ms): %ld\n", total_age / releases);
        else

diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index 593218d8a54d04d0c4b982068ebfe05463feb261..71919f7a31dc802efa1db2cbc1f05e54e3e7ece9 100644 (file)
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -894,6 +894,35 @@ TRACE_EVENT(nfsd_file_fsnotify_handle_event,
                        __entry->nlink, __entry->mode, __entry->mask)
 );
 
+DECLARE_EVENT_CLASS(nfsd_file_lruwalk_class,
+       TP_PROTO(
+               unsigned long removed,
+               unsigned long remaining
+       ),
+       TP_ARGS(removed, remaining),
+       TP_STRUCT__entry(
+               __field(unsigned long, removed)
+               __field(unsigned long, remaining)
+       ),
+       TP_fast_assign(
+               __entry->removed = removed;
+               __entry->remaining = remaining;
+       ),
+       TP_printk("%lu entries removed, %lu remaining",
+               __entry->removed, __entry->remaining)
+);
+
+#define DEFINE_NFSD_FILE_LRUWALK_EVENT(name)                           \
+DEFINE_EVENT(nfsd_file_lruwalk_class, name,                            \
+       TP_PROTO(                                                       \
+               unsigned long removed,                                  \
+               unsigned long remaining                                 \
+       ),                                                              \
+       TP_ARGS(removed, remaining))
+
+DEFINE_NFSD_FILE_LRUWALK_EVENT(nfsd_file_gc_removed);
+DEFINE_NFSD_FILE_LRUWALK_EVENT(nfsd_file_shrinker_removed);
+
 #include "cache.h"
 
 TRACE_DEFINE_ENUM(RC_DROPIT);