From: Tony Jones <tonyj@suse.de>
To: Michal Hocko <mhocko@suse.cz>,
Janani Ravichandran <janani.rvchndrn@gmail.com>
Cc: Rik van Riel <riel@surriel.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, hannes@cmpxchg.org,
vdavydov@virtuozzo.com, vbabka@suse.cz,
mgorman@techsingularity.net, kirill.shutemov@linux.intel.com,
bywxiaobai@163.com
Subject: Re: [PATCH 1/3] Add a new field to struct shrinker
Date: Fri, 22 Jul 2016 21:05:31 -0700 [thread overview]
Message-ID: <8663a3c5-7b9b-c5b5-cddd-224e97171921@suse.de> (raw)
In-Reply-To: <9c67941f-05f0-0d3e-ecc8-dcea60254c8b@suse.de>
On 07/22/2016 06:27 PM, Tony Jones wrote:
> On 07/20/2016 07:54 AM, Michal Hocko wrote:
>
>>> Michal, just to make sure I understand you correctly, do you mean that we
>>> could infer the names of the shrinkers by looking at the names of their callbacks?
>>
>> Yes, %ps can then be used for the name of the shrinker structure
>> (assuming it is available).
>
> This is fine for emitting via the ftrace /sys interface, but in order to have the data [name] get
> marshalled thru to perf (for example) you need to add it to the TP_fast_assign entry.
>
> tony
Unfortunately, %ps/%pF doesn't do much (re: Michal's comment "assuming it is available"):
- 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("%pF %p(%ps): nid: %d 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->shr,
__entry->nid,
__entry->nr_objects_to_shrink,
# cat trace_pipe
bash-1917 [003] ...1 2925.941062: mm_shrink_slab_start: super_cache_scan+0x0/0x1a0 ffff88042bb60cc0(0xffff88042bb60cc0): nid: 0 objects to shrink 0 gfp_flags GFP_KERNEL pgs_scanned 1000 lru_pgs 1000 cache items 4 delta 7 total_scan 7
Otherwise what I was suggesting was something like this to ensure it was correctly marshaled for perf/etc:
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -16,6 +16,8 @@
#define RECLAIM_WB_SYNC 0x0004u /* Unused, all reclaim async */
#define RECLAIM_WB_ASYNC 0x0008u
+#define SHRINKER_NAME_LEN (size_t)32
+
#define show_reclaim_flags(flags) \
(flags) ? __print_flags(flags, "|", \
{RECLAIM_WB_ANON, "RECLAIM_WB_ANON"}, \
@@ -191,6 +193,7 @@ TRACE_EVENT(mm_shrink_slab_start,
TP_STRUCT__entry(
__field(struct shrinker *, shr)
__field(void *, shrink)
+ __array(char, name, SHRINKER_NAME_LEN);
__field(int, nid)
__field(long, nr_objects_to_shrink)
__field(gfp_t, gfp_flags)
@@ -202,6 +205,11 @@ TRACE_EVENT(mm_shrink_slab_start,
),
TP_fast_assign(
+ char sym[KSYM_SYMBOL_LEN];
+
+ sprint_symbol(sym, (unsigned long)shr);
+ strlcpy(__entry->name, sym, SHRINKER_NAME_LEN);
+
__entry->shr = shr;
__entry->shrink = shr->scan_objects;
__entry->nid = sc->nid;
@@ -214,9 +222,10 @@ 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("%pF %p(%s): nid: %d 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->name,
__entry->nid,
__entry->nr_objects_to_shrink,
show_gfp_flags(__entry->gfp_flags),
@@ -236,6 +245,7 @@ TRACE_EVENT(mm_shrink_slab_end,
TP_STRUCT__entry(
__field(struct shrinker *, shr)
+ __array(char, name, SHRINKER_NAME_LEN);
__field(int, nid)
__field(void *, shrink)
__field(long, unused_scan)
@@ -245,6 +255,11 @@ TRACE_EVENT(mm_shrink_slab_end,
),
TP_fast_assign(
+ char sym[KSYM_SYMBOL_LEN];
+
+ sprint_symbol(sym, (unsigned long)shr);
+ strlcpy(__entry->name, sym, SHRINKER_NAME_LEN);
+
__entry->shr = shr;
__entry->nid = nid;
__entry->shrink = shr->scan_objects;
@@ -254,9 +269,10 @@ 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("%pF %p(%pF): nid: %d unused scan count %ld new scan count %ld total_scan %ld last shrinker return val %d",
__entry->shrink,
__entry->shr,
+ __entry->shr,
__entry->nid,
__entry->unused_scan,
__entry->new_scan,
next prev parent reply other threads:[~2016-07-23 4:05 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-09 8:33 [PATCH 0/3] Add names of shrinkers and have tracepoints display them Janani Ravichandran
2016-07-09 8:43 ` [PATCH 1/3] Add a new field to struct shrinker Janani Ravichandran
2016-07-11 6:37 ` Michal Hocko
2016-07-11 14:12 ` Rik van Riel
2016-07-11 14:33 ` Michal Hocko
2016-07-20 14:41 ` Janani Ravichandran
2016-07-20 14:54 ` Michal Hocko
2016-07-23 1:27 ` Tony Jones
2016-07-23 4:05 ` Tony Jones [this message]
2016-07-23 19:43 ` Rik van Riel
2016-07-23 23:21 ` Tony Jones
2016-07-26 16:40 ` Tony Jones
2016-07-28 5:49 ` Dave Chinner
2016-07-28 10:25 ` Mel Gorman
2016-07-29 0:13 ` Dave Chinner
2016-07-29 13:00 ` Mel Gorman
2016-08-12 3:09 ` Tony Jones
2016-07-09 8:52 ` [PATCH 2/3] Update name field for all shrinker instances Janani Ravichandran
2016-07-13 0:43 ` Tony Jones
2016-07-09 9:05 ` [PATCH 3/3] Add name fields in shrinker tracepoint definitions Janani Ravichandran
2016-07-09 9:45 ` kbuild test robot
2016-07-11 14:18 ` Vlastimil Babka
2016-07-13 0:35 ` Tony Jones
2016-07-13 6:16 ` Janani Ravichandran
2016-07-13 19:12 ` Tony Jones
2016-07-13 19:48 ` Rik van Riel
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