From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758383AbcGKOSo (ORCPT ); Mon, 11 Jul 2016 10:18:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:60728 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754609AbcGKOSn (ORCPT ); Mon, 11 Jul 2016 10:18:43 -0400 Subject: Re: [PATCH 3/3] Add name fields in shrinker tracepoint definitions To: Janani Ravichandran , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <6114f72a15d5e52984ea546ba977737221351636.1468051282.git.janani.rvchndrn@gmail.com> Cc: riel@surriel.com, akpm@linux-foundation.org, hannes@cmpxchg.org, vdavydov@virtuozzo.com, mhocko@suse.com, mgorman@techsingularity.net, kirill.shutemov@linux.intel.com, bywxiaobai@163.com From: Vlastimil Babka Message-ID: <447d8214-3c3d-cc4a-2eff-a47923fbe45f@suse.cz> Date: Mon, 11 Jul 2016 16:18:35 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: <6114f72a15d5e52984ea546ba977737221351636.1468051282.git.janani.rvchndrn@gmail.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/09/2016 11:05 AM, Janani Ravichandran wrote: > Currently, the mm_shrink_slab_start and mm_shrink_slab_end > tracepoints tell us how much time was spent in a shrinker, the number of > objects scanned, etc. But there is no information about the identity of > the shrinker. This patch enables the trace output to display names of > shrinkers. > > --- > include/trace/events/vmscan.h | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h > index 0101ef3..be4c5b0 100644 > --- a/include/trace/events/vmscan.h > +++ b/include/trace/events/vmscan.h > @@ -189,6 +189,7 @@ TRACE_EVENT(mm_shrink_slab_start, > cache_items, delta, total_scan), > > TP_STRUCT__entry( > + __field(char *, name) > __field(struct shrinker *, shr) > __field(void *, shrink) > __field(int, nid) > @@ -202,6 +203,7 @@ TRACE_EVENT(mm_shrink_slab_start, > ), > > TP_fast_assign( > + __entry->name = shr->name; > __entry->shr = shr; > __entry->shrink = shr->scan_objects; > __entry->nid = sc->nid; > @@ -214,7 +216,8 @@ TRACE_EVENT(mm_shrink_slab_start, > __entry->total_scan = total_scan; > ), > > - TP_printk("%pF %p: nid: %d objects to shrink %ld gfp_flags %s pgs_scanned %ld lru_pgs %ld cache items %ld delta %lld total_scan %ld", > + TP_printk("name: %s %pF %p: nid: %d objects to shrink %ld gfp_flags %s pgs_scanned %ld lru_pgs %ld cache items %ld delta %lld total_scan %ld", > + __entry->name, Is this legal to do when printing is not done via the /sys ... file itself, but raw data is collected and then printed by e.g. trace-cmd? How can it possibly interpret the "char *" kernel pointer? > __entry->shrink, > __entry->shr, > __entry->nid, > @@ -235,6 +238,7 @@ TRACE_EVENT(mm_shrink_slab_end, > total_scan), > > TP_STRUCT__entry( > + __field(char *, name) > __field(struct shrinker *, shr) > __field(int, nid) > __field(void *, shrink) > @@ -245,6 +249,7 @@ TRACE_EVENT(mm_shrink_slab_end, > ), > > TP_fast_assign( > + __entry->name = shr->name; > __entry->shr = shr; > __entry->nid = nid; > __entry->shrink = shr->scan_objects; > @@ -254,7 +259,8 @@ TRACE_EVENT(mm_shrink_slab_end, > __entry->total_scan = total_scan; > ), > > - TP_printk("%pF %p: nid: %d unused scan count %ld new scan count %ld total_scan %ld last shrinker return val %d", > + TP_printk("name: %s %pF %p: nid: %d unused scan count %ld new scan count %ld total_scan %ld last shrinker return val %d", > + __entry->name, > __entry->shrink, > __entry->shr, > __entry->nid, >