On 01.09.2021 14:36, Nikita Yushchenko wrote:
High order allocation detector monitors allocations of order greater
than zero, and generates an uevent if a configured number of allocations
happen within configured time.
In return to this uevent, userspace can enable event tracing. If a
stream of high-order allocations continues, the trace could help to
detect the code path causing them.
HOAD has a sysfs control interface, at /sys/kernel/mm/hoad/control:
- "enable ORDER COUNT MSECS"
Sets up monitoring allocations of order ORDER: if COUNT such
allocations are detected within MSECS, uevent is sent. Then further
uevents is suspended, to avoid userspace races.
- "disable ORDER"
Stops monitoring allocations of order ORDER.
- "resume [delay-msecs]"
Allow sending a new uevent, either immediately or after the given
delay.
The uevent is generated with ACTION="change", SUBSYSTEM="hoad", ORDER
set to the order of the allocation that has caused the uevent.
Also HOAD provides a tracepoint named "hoad", under kmem/ group, that
could be used for tracing. This tracepoint hits on every allocation of
order greater or equal to minimal order for which monitoring is enabled.
https://jira.sw.ru/browse/PSBM-92088
Signed-off-by: Nikita Yushchenko <[email protected]>
---
include/trace/events/kmem.h | 12 ++
mm/page_alloc.c | 266 ++++++++++++++++++++++++++++++++++++
2 files changed, 278 insertions(+)
diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index 9cb647609df3..b425c6856bfd 100644
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -305,6 +305,18 @@ TRACE_EVENT(mm_page_alloc_extfrag,
__entry->alloc_migratetype == __entry->fallback_migratetype)
);
+TRACE_EVENT(hoad,
+ TP_PROTO(int order),
+ TP_ARGS(order),
+ TP_STRUCT__entry(
+ __field(int, order)
+ ),
+ TP_fast_assign(
+ __entry->order = order;
+ ),
+ TP_printk("order=%d", __entry->order)
+);
+
#endif /* _TRACE_KMEM_H */
/* This part must be outside protection */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1ae193b26a1d..959b1bfbafef 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3533,6 +3533,270 @@ static __always_inline void warn_high_order(int order,
gfp_t gfp_mask)
}
}
+struct hoad_order_info {
+ unsigned long interval;
+ int max_allocs;
+ atomic_t counter;
+ unsigned long since_jiffies;
+ struct timer_list reset_counter_timer;
+};
+
+static struct hoad_order_info *hoad_table[MAX_ORDER];
+static DEFINE_MUTEX(hoad_mutex);
+static struct kobject *hoad_kobj;
+static int hoad_uevent_order;
+static unsigned long hoad_resume_jiffies;
+static int hoad_trace_min_order;
+
+#define MSEC_PER_MINUTE (60 * MSEC_PER_SEC)
+#define MSEC_PER_HOUR (60 * MSEC_PER_MINUTE)
+#define MSEC_PER_DAY (60 * MSEC_PER_HOUR)
Missprint?
--
Best regards, Tikhomirov Pavel
Software Developer, Virtuozzo.
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