From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: [PATCH 02/14] vmscan: add shrink_slab tracepoints Date: Fri, 8 Jul 2011 14:14:34 +1000 Message-ID: <1310098486-6453-3-git-send-email-david@fromorbit.com> References: <1310098486-6453-1-git-send-email-david@fromorbit.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org To: viro@ZenIV.linux.org.uk Return-path: In-Reply-To: <1310098486-6453-1-git-send-email-david@fromorbit.com> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org From: Dave Chinner =D0=86t 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 --- include/trace/events/vmscan.h | 71 +++++++++++++++++++++++++++++++++++= ++++++ mm/vmscan.c | 8 ++++- 2 files changed, 78 insertions(+), 1 deletions(-) diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.= h index b2c33bd..5f3fea4 100644 --- a/include/trace/events/vmscan.h +++ b/include/trace/events/vmscan.h @@ -179,6 +179,77 @@ DEFINE_EVENT(mm_vmscan_direct_reclaim_end_template, = mm_vmscan_memcg_softlimit_re TP_ARGS(nr_reclaimed) ); =20 +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(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 =3D shr; + __entry->nr_objects_to_shrink =3D nr_objects_to_shrink; + __entry->gfp_flags =3D sc->gfp_mask; + __entry->pgs_scanned =3D pgs_scanned; + __entry->lru_pgs =3D lru_pgs; + __entry->cache_items =3D cache_items; + __entry->delta =3D delta; + __entry->total_scan =3D total_scan; + ), + + TP_printk("shrinker %p: objects to shrink %ld gfp_flags %s pgs_scanned = %ld lru_pgs %ld cache items %ld delta %lld total_scan %ld", + __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(long, unused_scan) + __field(long, new_scan) + __field(int, retval) + __field(long, total_scan) + ), + + TP_fast_assign( + __entry->shr =3D shr; + __entry->unused_scan =3D unused_scan_cnt; + __entry->new_scan =3D new_scan_cnt; + __entry->retval =3D shrinker_retval; + __entry->total_scan =3D new_scan_cnt - unused_scan_cnt; + ), + + TP_printk("shrinker %p: unused scan count %ld new scan count %ld total_= scan %ld last shrinker return val %d", + __entry->shr, + __entry->unused_scan, + __entry->new_scan, + __entry->total_scan, + __entry->retval) +); =20 DECLARE_EVENT_CLASS(mm_vmscan_lru_isolate_template, =20 diff --git a/mm/vmscan.c b/mm/vmscan.c index 8ff834e..646cb6c 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -250,6 +250,7 @@ unsigned long shrink_slab(struct shrink_control *shri= nk, unsigned long long delta; unsigned long total_scan; unsigned long max_pass; + int shrink_ret =3D 0; =20 max_pass =3D do_shrinker_shrink(shrinker, shrink, 0); delta =3D (4 * nr_pages_scanned) / shrinker->seeks; @@ -274,9 +275,12 @@ unsigned long shrink_slab(struct shrink_control *shr= ink, total_scan =3D shrinker->nr; shrinker->nr =3D 0; =20 + trace_mm_shrink_slab_start(shrinker, shrink, total_scan, + nr_pages_scanned, lru_pages, + max_pass, delta, total_scan); + while (total_scan >=3D SHRINK_BATCH) { long this_scan =3D SHRINK_BATCH; - int shrink_ret; int nr_before; =20 nr_before =3D do_shrinker_shrink(shrinker, shrink, 0); @@ -293,6 +297,8 @@ unsigned long shrink_slab(struct shrink_control *shri= nk, } =20 shrinker->nr +=3D total_scan; + trace_mm_shrink_slab_end(shrinker, shrink_ret, total_scan, + shrinker->nr); } up_read(&shrinker_rwsem); out: --=20 1.7.5.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter= .ca/ Don't email: email@kvack.org