Currently zsmalloc is widely used in android device. Sometimes, we want
to see how frequently zs_compact is triggered or how may pages freed by
zs_compact(), or which zsmalloc pool is compacted.
We have backported the zs_compact() to our product(kernel 3.18). It is
usefull for a longtime running device. But there is not a convenient
way to get the detailed information of zs_comapct() which is usefull
for performance optimization. Information about how much time
zs_compact used, which pool is compacted, how many page freed, etc.
With these information, we will know what is going on in zs_comapct.
And draw the relation between free mem and zs_comapct.
Most of the time, user can get the brief information from
trace_mm_shrink_slab_[start | end], but in some senario, they do not use
zsmalloc shrinker, but trigger compaction manually. So add some trace
events in zs_compact is convenient. Also we can add some zsmalloc
specific information(pool name, total compact pages, etc) in zsmalloc
trace.
This patch add two trace events for zs_compact(), below the trace log:
-----------------------------
root@land:/ # cat /d/tracing/trace
kswapd0-125 [007] ...1 174.176979: zsmalloc_compact_start: pool zram0
kswapd0-125 [007] ...1 174.181967: zsmalloc_compact_end: pool zram0: 608 pages compacted(total 1794)
kswapd0-125 [000] ...1 184.134475: zsmalloc_compact_start: pool zram0
kswapd0-125 [000] ...1 184.135010: zsmalloc_compact_end: pool zram0: 62 pages compacted(total 1856)
kswapd0-125 [003] ...1 226.927221: zsmalloc_compact_start: pool zram0
kswapd0-125 [003] ...1 226.928575: zsmalloc_compact_end: pool zram0: 250 pages compacted(total 2106)
-----------------------------
Link: http://lkml.kernel.org/r/1465289804-4913-1-git-send-email-opensource.ganesh@gmail.com
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
--- /dev/null
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM zsmalloc
+
+#if !defined(_TRACE_ZSMALLOC_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_ZSMALLOC_H
+
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(zsmalloc_compact_start,
+
+ TP_PROTO(const char *pool_name),
+
+ TP_ARGS(pool_name),
+
+ TP_STRUCT__entry(
+ __field(const char *, pool_name)
+ ),
+
+ TP_fast_assign(
+ __entry->pool_name = pool_name;
+ ),
+
+ TP_printk("pool %s",
+ __entry->pool_name)
+);
+
+TRACE_EVENT(zsmalloc_compact_end,
+
+ TP_PROTO(const char *pool_name, unsigned long pages_compacted,
+ unsigned long pages_total_compacted),
+
+ TP_ARGS(pool_name, pages_compacted, pages_total_compacted),
+
+ TP_STRUCT__entry(
+ __field(const char *, pool_name)
+ __field(unsigned long, pages_compacted)
+ __field(unsigned long, pages_total_compacted)
+ ),
+
+ TP_fast_assign(
+ __entry->pool_name = pool_name;
+ __entry->pages_compacted = pages_compacted;
+ __entry->pages_total_compacted = pages_total_compacted;
+ ),
+
+ TP_printk("pool %s: %ld pages compacted(total %ld)",
+ __entry->pool_name,
+ __entry->pages_compacted,
+ __entry->pages_total_compacted)
+);
+
+#endif /* _TRACE_ZSMALLOC_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#define CREATE_TRACE_POINTS
+
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mount.h>
#include <linux/migrate.h>
#include <linux/pagemap.h>
+#include <trace/events/zsmalloc.h>
#define ZSPAGE_MAGIC 0x58
{
int i;
struct size_class *class;
+ unsigned long pages_compacted_before = pool->stats.pages_compacted;
+
+ trace_zsmalloc_compact_start(pool->name);
for (i = zs_size_classes - 1; i >= 0; i--) {
class = pool->size_class[i];
__zs_compact(pool, class);
}
+ trace_zsmalloc_compact_end(pool->name,
+ pool->stats.pages_compacted - pages_compacted_before,
+ pool->stats.pages_compacted);
+
return pool->stats.pages_compacted;
}
EXPORT_SYMBOL_GPL(zs_compact);