A new perf script page-reclaim is introduced in this patchset.
This new script is used to report the page reclaim details. The possible
usage of this script is as bellow,
- identify latency spike caused by direct reclaim
- whehter the latency spike is relevant with pageout
- why is page reclaim requested, i.e. whether it is because of memory
fragmentation
- page reclaim efficiency
etc
In the future we may also enhance it to analyze the memcg reclaim.
Bellow is how to use this script,
# Record, one of the following
$ perf record -e 'vmscan:mm_vmscan_*' ./workload
$ perf script record page-reclaim
# Report
$ perf script report page-reclaim
# Report per process latency
$ perf script report page-reclaim -- -p
# Report per process latency details. At what time and how long it
# stalls at each time.
$ perf script report page-reclaim -- -v
An example of the script's report,
$ perf script report page-reclaim
Direct reclaims: 4924
Direct latency (ms) total max avg min
177823.211 6378.977 36.114 0.051
Direct file reclaimed 22920
Direct file scanned 28306
Direct file sync write I/O 0
Direct file async write I/O 0
Direct anon reclaimed 212567
Direct anon scanned 1446854
Direct anon sync write I/O 0
Direct anon async write I/O 278325
Direct order 0 1 3
4870 23 31
Wake kswapd requests 716
Wake order 0 1
715 1
Kswapd reclaims: 9
Kswapd latency (ms) total max avg min
86353.046 42128.816 9594.783 120.736
Kswapd file reclaimed 366461
Kswapd file scanned 369554
Kswapd file sync write I/O 0
Kswapd file async write I/O 0
Kswapd anon reclaimed 362594
Kswapd anon scanned 693938
Kswapd anon sync write I/O 0
Kswapd anon async write I/O 330663
Kswapd order 0 1 3
3 1 5
Kswapd re-wakes 705
Per process latency (ms):
pid[comm] total max avg min
timestamp latency(ns)
1[systemd] 276.764 248.933 21.29 0.293
3406860552338: 16819800
3406877381650: 5532855
3407458799399: 929517
3407459796042: 916682
3407460763220: 418989
3407461250236: 332355
3407461637534: 401731
3407462092234: 449219
3407462605855: 292857
3407462952343: 372700
3407463364947: 414880
3407463829547: 949162
3407464813883: 248933444
163[kswapd0] 86353.046 42128.816 9594.783 120.736
3357637025977: 1026962745
3358915619888: 41268642175
3400239664127: 42128816204
3443784780373: 679641989
3444847948969: 120735792
3445001978784: 342713657
3445835850664: 316851589
3446865035476: 247457873
3449355401352: 221223878
...
This script must be in sync with bellow vmscan tracepoints,
mm_vmscan_direct_reclaim_begin
mm_vmscan_direct_reclaim_end
mm_vmscan_kswapd_wake
mm_vmscan_kswapd_sleep
mm_vmscan_wakeup_kswapd
mm_vmscan_lru_shrink_inactive
mm_vmscan_writepage
Currently there's no easy way to make perf scripts in sync with
tracepoints. One possible way is to run perf's tests regularly, another way
is once we changes the definitions of tracepoints we must keep in mind that
the perf scripts which are using these tracepoints must be changed as well.
So I add some comment for the new introduced page-reclaim script as a
reminder.
Yafang Shao (2):
perf script python: integrate page reclaim analyze script
tracing, vmscan: add comments for perf script page-reclaim
include/trace/events/vmscan.h | 15 +-
tools/perf/scripts/python/bin/page-reclaim-record | 2 +
tools/perf/scripts/python/bin/page-reclaim-report | 4 +
tools/perf/scripts/python/page-reclaim.py | 378 ++++++++++++++++++++++
4 files changed, 398 insertions(+), 1 deletion(-)
create mode 100644 tools/perf/scripts/python/bin/page-reclaim-record
create mode 100644 tools/perf/scripts/python/bin/page-reclaim-report
create mode 100644 tools/perf/scripts/python/page-reclaim.py
--
1.8.3.1
A new perf script page-reclaim is introduced in this patch. This new script
is used to report the page reclaim details. The possible usage of this
script is as bellow,
- identify latency spike caused by direct reclaim
- whehter the latency spike is relevant with pageout
- why is page reclaim requested, i.e. whether it is because of memory
fragmentation
- page reclaim efficiency
etc
In the future we may also enhance it to analyze the memcg reclaim.
Bellow is how to use this script,
# Record, one of the following
$ perf record -e 'vmscan:mm_vmscan_*' ./workload
$ perf script record page-reclaim
# Report
$ perf script report page-reclaim
# Report per process latency
$ perf script report page-reclaim -- -p
# Report per process latency details. At what time and how long it
# stalls at each time.
$ perf script report page-reclaim -- -v
An example of doing mmtests,
$ perf script report page-reclaim
Direct reclaims: 4924
Direct latency (ms) total max avg min
177823.211 6378.977 36.114 0.051
Direct file reclaimed 22920
Direct file scanned 28306
Direct file sync write I/O 0
Direct file async write I/O 0
Direct anon reclaimed 212567
Direct anon scanned 1446854
Direct anon sync write I/O 0
Direct anon async write I/O 278325
Direct order 0 1 3
4870 23 31
Wake kswapd requests 716
Wake order 0 1
715 1
Kswapd reclaims: 9
Kswapd latency (ms) total max avg min
86353.046 42128.816 9594.783 120.736
Kswapd file reclaimed 366461
Kswapd file scanned 369554
Kswapd file sync write I/O 0
Kswapd file async write I/O 0
Kswapd anon reclaimed 362594
Kswapd anon scanned 693938
Kswapd anon sync write I/O 0
Kswapd anon async write I/O 330663
Kswapd order 0 1 3
3 1 5
Kswapd re-wakes 705
$ perf script report page-reclaim -- -p
# besides the above basic output, it will also summary per task
# latency
Per process latency (ms):
pid[comm] total max avg min
1[systemd] 276.764 248.933 21.29 0.293
163[kswapd0] 86353.046 42128.816 9594.783 120.736
7241[bash] 12787.749 859.091 94.028 0.163
1592[master] 81.604 70.811 27.201 2.906
1595[pickup] 496.162 374.168 165.387 14.478
1098[auditd] 19.32 19.32 19.32 19.32
1120[irqbalance] 5232.331 1386.352 158.555 0.169
7236[usemem] 79649.04 1763.281 24.921 0.051
1605[sshd] 1344.41 645.125 34.472 0.16
7238[bash] 1158.92 1023.307 231.784 0.067
7239[bash] 15100.776 993.447 82.069 0.145
...
$ per script report page-reclaim -- -v
# Besides the basic output, it will asl show per task latency details
Per process latency (ms):
pid[comm] total max avg min
timestamp latency(ns)
1[systemd] 276.764 248.933 21.29 0.293
3406860552338: 16819800
3406877381650: 5532855
3407458799399: 929517
3407459796042: 916682
3407460763220: 418989
3407461250236: 332355
3407461637534: 401731
3407462092234: 449219
3407462605855: 292857
3407462952343: 372700
3407463364947: 414880
3407463829547: 949162
3407464813883: 248933444
163[kswapd0] 86353.046 42128.816 9594.783 120.736
3357637025977: 1026962745
3358915619888: 41268642175
3400239664127: 42128816204
3443784780373: 679641989
3444847948969: 120735792
3445001978784: 342713657
3445835850664: 316851589
3446865035476: 247457873
3449355401352: 221223878
...
This script must be in sync with bellow vmscan tracepoints,
mm_vmscan_direct_reclaim_begin
mm_vmscan_direct_reclaim_end
mm_vmscan_kswapd_wake
mm_vmscan_kswapd_sleep
mm_vmscan_wakeup_kswapd
mm_vmscan_lru_shrink_inactive
mm_vmscan_writepage
Signed-off-by: Yafang Shao <[email protected]>
---
tools/perf/scripts/python/bin/page-reclaim-record | 2 +
tools/perf/scripts/python/bin/page-reclaim-report | 4 +
tools/perf/scripts/python/page-reclaim.py | 378 ++++++++++++++++++++++
3 files changed, 384 insertions(+)
create mode 100644 tools/perf/scripts/python/bin/page-reclaim-record
create mode 100644 tools/perf/scripts/python/bin/page-reclaim-report
create mode 100644 tools/perf/scripts/python/page-reclaim.py
diff --git a/tools/perf/scripts/python/bin/page-reclaim-record b/tools/perf/scripts/python/bin/page-reclaim-record
new file mode 100644
index 0000000..5a16a23
--- /dev/null
+++ b/tools/perf/scripts/python/bin/page-reclaim-record
@@ -0,0 +1,2 @@
+#!/bin/bash
+perf record -e vmscan:mm_vmscan_direct_reclaim_begin -e vmscan:mm_vmscan_direct_reclaim_end -e vmscan:mm_vmscan_kswapd_wake -e vmscan:mm_vmscan_kswapd_sleep -e vmscan:mm_vmscan_wakeup_kswapd -e vmscan:mm_vmscan_lru_shrink_inactive -e vmscan:mm_vmscan_writepage $@
diff --git a/tools/perf/scripts/python/bin/page-reclaim-report b/tools/perf/scripts/python/bin/page-reclaim-report
new file mode 100644
index 0000000..b74e197
--- /dev/null
+++ b/tools/perf/scripts/python/bin/page-reclaim-report
@@ -0,0 +1,4 @@
+#!/bin/bash
+#description: display page reclaim details
+#args: [-h] [-p] [-v]
+perf script -s "$PERF_EXEC_PATH"/scripts/python/page-reclaim.py $@
diff --git a/tools/perf/scripts/python/page-reclaim.py b/tools/perf/scripts/python/page-reclaim.py
new file mode 100644
index 0000000..5c0bd64
--- /dev/null
+++ b/tools/perf/scripts/python/page-reclaim.py
@@ -0,0 +1,378 @@
+# SPDX-License-Identifier: GPL-2.0
+# Perf script to help analyze page reclaim with vmscan tracepoints
+# e.g. to capture the latency spike caused by direct reclaim.
+#
+# This script is motivated by Mel's trace-vmscan-postprocess.pl.
+#
+# Author: Yafang Shao <[email protected]>
+
+import os
+import sys
+import getopt
+import signal
+
+signal.signal(signal.SIGPIPE, signal.SIG_DFL)
+
+usage = "usage: perf script report page-reclaim -- [-h] [-p] [-v]\n"
+
+latency_metric = ['total', 'max', 'avg', 'min']
+reclaim_path = ['Kswapd', 'Direct']
+sync_io = ['async', 'sync']
+lru = ['anon', 'file']
+
+class Show:
+ DEFAULT = 0
+ PROCCESS = 1
+ VERBOSE = 2
+
+show_opt = Show.DEFAULT
+
+def ns(sec, nsec):
+ return (sec * 1000000000) + nsec
+
+def ns_to_ms(ns):
+ return round(ns / 1000000.0, 3)
+
+def print_proc_latency(_list, pid, comm):
+ line = pid.rjust(8)
+ line += comm.ljust(12)
+ line += "".join(map(lambda x: str(x).rjust(12), _list))
+
+ print(line)
+
+def print_stat_list(__list, title, padding):
+ width = len(title) + 1
+ header = title.ljust(width)
+ line = ''.ljust(width)
+
+ for v in __list:
+ header += str(v[0]).rjust(padding)
+ line += str(v[1]).rjust(padding)
+
+ print(header)
+ print(line)
+
+class Trace:
+ def __init__(self, secs, nsecs):
+ self.begin = ns(secs, nsecs)
+
+ def complete(self, secs, nsecs):
+ self.ns = ns(secs, nsecs) - self.begin
+
+class Stat:
+ def __init__(self):
+ self.stats = {}
+ self.stats['file'] = {}
+ self.stats['file']['reclaimed'] = 0
+ self.stats['file']['scanned'] = 0
+ self.stats['file']['sync'] = 0
+ self.stats['file']['async'] = 0
+ self.stats['anon'] = {}
+ self.stats['anon']['reclaimed'] = 0
+ self.stats['anon']['scanned'] = 0
+ self.stats['anon']['sync'] = 0
+ self.stats['anon']['async'] = 0
+
+ # including reclaimed slab caches
+ self.stats['reclaimed'] = 0
+
+ # The MAX_ORDER in kernel is configurable
+ self.stats['order'] = {}
+
+ self.stats['latency'] = {}
+ self.stats['latency']['total'] = 0.0
+ self.stats['latency']['max'] = 0.0
+ self.stats['latency']['avg'] = 0.0
+ self.stats['latency']['min'] = float("inf")
+ self.stats['count'] = 0
+
+ def add_latency(self, val, order):
+ self.stats['latency']['total'] += val
+ _max = self.stats['latency']['max']
+ _min = self.stats['latency']['min']
+ if val > _max:
+ self.stats['latency']['max'] = val
+ if val < _min:
+ self.stats['latency']['min'] = val
+
+ self.stats['count'] += 1
+ self.stats['order'][order] = self.stats['order'].get(order, 0) + 1
+
+ def add_page(self, _lru, scanned, reclaimed):
+ self.stats[_lru]['scanned'] += scanned
+ self.stats[_lru]['reclaimed'] += reclaimed
+
+ def inc_write_io(self, _lru, _io):
+ self.stats[_lru][_io] += 1
+
+ def convert_latency(self):
+ count = self.stats['count']
+ if count:
+ self.stats['latency']['avg'] = \
+ self.stats['latency']['total'] / count
+ for i, v in self.stats['latency'].items():
+ self.stats['latency'][i] = ns_to_ms(v)
+
+ latency_list = sorted(self.stats['latency'].items(),
+ key=lambda i:latency_metric.index(i[0]))
+
+ return latency_list
+
+ def show_stats(self, key):
+ count = self.stats['count']
+ print("%s reclaims: %d" % (key, count))
+
+ # Format latency output
+ # Print latencys in milliseconds:
+ # title total max avg min
+ # v v v v
+ latency_list = self.convert_latency()
+ print_stat_list(latency_list, key + " latency (ms)", 12)
+
+ for _lru in ['file', 'anon']:
+ for action in ['reclaimed', 'scanned']:
+ print("%s %s %s %d" % (key, _lru, action, self.stats[_lru][action]))
+ for _io in ['sync', 'async']:
+ print("%s %s %s write I/O %d" % (key, _lru, _io, self.stats[_lru][_io]))
+
+ # Format order output
+ # Similar with /proc/buddyinfo:
+ # title order-N ...
+ # v ...
+ # N.B. v is a non-zero value
+ order_list = sorted(self.stats['order'].items())
+ print_stat_list(order_list, key + ' order', 6)
+
+class Vmscan:
+ events = {}
+ stat = {}
+ stat['Direct'] = Stat()
+ stat['Kswapd'] = Stat()
+ # for re-wake the kswapd
+ rewake = 0
+
+ @classmethod
+ def direct_begin(cls, pid, comm, start_secs, start_nsecs, order):
+ event = cls.events.get(pid)
+ if event is None:
+ #new vmscan instance
+ event = cls.events[pid] = Vmscan(comm, pid)
+ event.vmscan_trace_begin(start_secs, start_nsecs, order, 1)
+
+ @classmethod
+ def direct_end(cls, pid, secs, nsecs, reclaimed):
+ event = cls.events.get(pid)
+ if event and event.tracing():
+ event.vmscan_trace_end(secs, nsecs)
+
+ @classmethod
+ def kswapd_wake(cls, pid, comm, start_secs, start_nsecs, order):
+ event = cls.events.get(pid)
+ if event is None:
+ # new vmscan instance
+ event = cls.events[pid] = Vmscan(comm, pid)
+
+ if event.tracing() is False:
+ event.vmscan_trace_begin(start_secs, start_nsecs, order, 0)
+ # kswapd is already running
+ else:
+ cls.rewake_kswapd(order)
+
+ @classmethod
+ def rewake_kswapd(cls, order):
+ cls.rewake += 1
+
+ @classmethod
+ def show_rewakes(cls):
+ print("Kswapd re-wakes %d" % (cls.rewake))
+
+ @classmethod
+ def kswapd_sleep(cls, pid, secs, nsecs):
+ event = cls.events.get(pid)
+ if event and event.tracing():
+ event.vmscan_trace_end(secs, nsecs)
+
+ @classmethod
+ def shrink_inactive(cls, pid, scanned, reclaimed, flags):
+ event = cls.events.get(pid)
+ if event and event.tracing():
+ # RECLAIM_WB_ANON 0x1
+ # RECLAIM_WB_FILE 0x2
+ _type = (flags & 0x2) >> 1
+ event.process_lru(lru[_type], scanned, reclaimed)
+
+ @classmethod
+ def writepage(cls, pid, flags):
+ event = cls.events.get(pid)
+ if event and event.tracing():
+ # RECLAIM_WB_ANON 0x1
+ # RECLAIM_WB_FILE 0x2
+ # RECLAIM_WB_SYNC 0x4
+ # RECLAIM_WB_ASYNC 0x8
+ _type = (flags & 0x2) >> 1
+ _io = (flags & 0x4) >> 2
+
+ event.process_writepage(lru[_type], sync_io[_io])
+
+ @classmethod
+ def iterate_proc(cls):
+ if show_opt != Show.DEFAULT:
+ print("\nPer process latency (ms):")
+ print_proc_latency(latency_metric, 'pid', '[comm]')
+
+ if show_opt == Show.VERBOSE:
+ print("%20s %s" % ('timestamp','latency(ns)'))
+
+ for i in cls.events:
+ yield cls.events[i]
+
+ def __init__(self, comm, pid):
+ self.comm = comm
+ self.pid = pid
+ self.trace = None
+ self._list = []
+ self.stat = Stat()
+ self.direct = 0
+ self.order = 0
+
+ def vmscan_trace_begin(self, secs, nsecs, order, direct):
+ self.trace = Trace(secs, nsecs)
+ self.direct = direct
+ self.order = order
+
+ def vmscan_trace_end(self, secs, nsecs):
+ path = reclaim_path[self.direct]
+ self.trace.complete(secs, nsecs)
+
+ Vmscan.stat[path].add_latency(self.trace.ns, self.order)
+ if show_opt != Show.DEFAULT:
+ self.stat.add_latency(self.trace.ns, self.order)
+ if show_opt == Show.VERBOSE:
+ self._list.append(self.trace)
+
+ self.trace = None
+
+ def process_lru(self, lru, scanned, reclaimed):
+ path = reclaim_path[self.direct]
+ Vmscan.stat[path].add_page(lru, scanned, reclaimed)
+
+ def process_writepage(self, lru, io):
+ path = reclaim_path[self.direct]
+ Vmscan.stat[path].inc_write_io(lru, io)
+
+ def tracing(self):
+ return self.trace != None
+
+ def display_proc(self):
+ self.stat.convert_latency()
+ print_proc_latency(sorted(self.stat.stats['latency'].itervalues(),
+ reverse=True),
+ str(self.pid),
+ '[' +self.comm[0:10] + ']')
+
+ def display_proc_detail(self):
+ if show_opt == Show.VERBOSE:
+ for i, v in enumerate(self._list):
+ print("%20d: %d" % (v.begin, v.ns))
+
+# Wake kswpad request
+class Wakeup:
+ wakes = 0
+ orders = {}
+
+ @classmethod
+ def wakeup_kswapd(cls, order):
+ cls.wakes += 1
+ cls.orders[order] = cls.orders.get(order, 0) + 1
+
+ @classmethod
+ def show_wakes(cls):
+ print("Wake kswapd requests %d" % (cls.wakes))
+
+ order_list = sorted(cls.orders.items())
+ print_stat_list(order_list, 'Wake order', 6)
+
+def trace_end():
+ Vmscan.stat['Direct'].show_stats('Direct')
+ Wakeup.show_wakes()
+ print('')
+
+ Vmscan.stat['Kswapd'].show_stats('Kswapd')
+ Vmscan.show_rewakes()
+
+ # show process details if requested
+ for i in Vmscan.iterate_proc():
+ i.display_proc(),
+ i.display_proc_detail()
+
+# These definations must be in sync with the vmscan tracepoints.
+def vmscan__mm_vmscan_direct_reclaim_begin(event_name, context, common_cpu,
+ common_secs, common_nsecs, common_pid, common_comm,
+ common_callchain, order, gfp_flags):
+
+ Vmscan.direct_begin(common_pid, common_comm, common_secs,
+ common_nsecs, order)
+
+def vmscan__mm_vmscan_direct_reclaim_end(event_name, context, common_cpu,
+ common_secs, common_nsecs, common_pid, common_comm,
+ common_callchain, nr_reclaimed):
+
+ Vmscan.direct_end(common_pid, common_secs, common_nsecs, nr_reclaimed)
+
+def vmscan__mm_vmscan_kswapd_wake(event_name, context, common_cpu,
+ common_secs, common_nsecs, common_pid, common_comm,
+ common_callchain, nid, zid, order):
+
+ Vmscan.kswapd_wake(common_pid, common_comm, common_secs, common_nsecs, order)
+
+def vmscan__mm_vmscan_kswapd_sleep(event_name, context, common_cpu,
+ common_secs, common_nsecs, common_pid, common_comm,
+ common_callchain, nid):
+
+ Vmscan.kswapd_sleep(common_pid, common_secs, common_nsecs)
+
+def vmscan__mm_vmscan_wakeup_kswapd(event_name, context, common_cpu,
+ common_secs, common_nsecs, common_pid, common_comm,
+ common_callchain, nid, zid, order, gfp_flags):
+
+ Wakeup.wakeup_kswapd(order)
+
+def vmscan__mm_vmscan_lru_shrink_inactive(event_name, context, common_cpu,
+ common_secs, common_nsecs, common_pid, common_comm,
+ common_callchain, nid, nr_scanned, nr_reclaimed, nr_dirty,
+ nr_writeback, nr_congested, nr_immediate, nr_activate_anon,
+ nr_activate_file, nr_ref_keep, nr_unmap_fail, priority, flags):
+
+ Vmscan.shrink_inactive(common_pid, nr_scanned, nr_reclaimed, flags)
+
+def vmscan__mm_vmscan_writepage(event_name, context, common_cpu,
+ common_secs, common_nsecs, common_pid, common_comm,
+ common_callchain, pfn, reclaim_flags):
+
+ Vmscan.writepage(common_pid, reclaim_flags)
+
+def print_help():
+ global usage
+ print(usage)
+ print(" -p show process latency (ms)")
+ print(" -v show process latency (ns) with timestamp")
+
+def option_parse():
+ try:
+ opts, args = getopt.getopt(sys.argv[1:], "pvh")
+ except getopt.GetoptError:
+ print('Bad option!')
+ exit(1)
+
+ global show_opt
+ for opt, arg in opts:
+ if opt == "-h":
+ print_help()
+ exit(0)
+ elif opt == "-p":
+ show_opt = Show.PROCCESS
+ elif opt == '-v':
+ show_opt = Show.VERBOSE
+
+option_parse()
+
--
1.8.3.1
Currently there's no easy way to make perf scripts in sync with
tracepoints. One possible way is to run perf's tests regularly, another way
is once we changes the definitions of tracepoints we must keep in mind that
the perf scripts which are using these tracepoints must be changed as well.
So I add this comment for the new introduced page-reclaim script as a
reminder.
Signed-off-by: Yafang Shao <[email protected]>
---
include/trace/events/vmscan.h | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index a5ab297..f0447ad 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -1,4 +1,17 @@
-/* SPDX-License-Identifier: GPL-2.0 */
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Bellow tracepoints are used by perf script page-reclaim:
+ * mm_vmscan_direct_reclaim_begin
+ * mm_vmscan_direct_reclaim_end
+ * mm_vmscan_kswapd_wake
+ * mm_vmscan_kswapd_sleep
+ * mm_vmscan_wakeup_kswapd
+ * mm_vmscan_lru_shrink_inactive
+ * mm_vmscan_writepage
+ * We must keep the definitions of these tracepoints in sync with the perf
+ * script page-reclaim.
+ */
+
#undef TRACE_SYSTEM
#define TRACE_SYSTEM vmscan
--
1.8.3.1
On 9/18/19 7:38 AM, Yafang Shao wrote:
> Currently there's no easy way to make perf scripts in sync with
> tracepoints. One possible way is to run perf's tests regularly, another way
> is once we changes the definitions of tracepoints we must keep in mind that
> the perf scripts which are using these tracepoints must be changed as well.
> So I add this comment for the new introduced page-reclaim script as a
> reminder.
>
> Signed-off-by: Yafang Shao <[email protected]>
This seems like the tail wagging the dog to me. If we added this to every tp defn that is used by a perf perl/python script the tp headers would be littered with such comments.
On 9/18/19 7:38 AM, Yafang Shao wrote:
> A new perf script page-reclaim is introduced in this patch. This new script
> is used to report the page reclaim details. The possible usage of this
> script is as bellow,
> - identify latency spike caused by direct reclaim
> - whehter the latency spike is relevant with pageout
> - why is page reclaim requested, i.e. whether it is because of memory
> fragmentation
> - page reclaim efficiency
> etc
> In the future we may also enhance it to analyze the memcg reclaim.
>
> Bellow is how to use this script,
> # Record, one of the following
> $ perf record -e 'vmscan:mm_vmscan_*' ./workload
> $ perf script record page-reclaim
>
> # Report
> $ perf script report page-reclaim
>
> # Report per process latency
> $ perf script report page-reclaim -- -p
I tested it with global-dhp__pagereclaim-performance from mmtests and got what appears to be reasonable results and the output looks correct and useful. However I'm not a vm expert so I can't comment further. Hopefully someone on linux-mm can give more specific feedback.
There is one issue with Python3, see below. I didn't test with Python2.
>
> + @classmethod
> + def shrink_inactive(cls, pid, scanned, reclaimed, flags):
> + event = cls.events.get(pid)
> + if event and event.tracing():
> + # RECLAIM_WB_ANON 0x1
> + # RECLAIM_WB_FILE 0x2
> + _type = (flags & 0x2) >> 1
> + event.process_lru(lru[_type], scanned, reclaimed)
> +
> + @classmethod
> + def writepage(cls, pid, flags):
> + event = cls.events.get(pid)
> + if event and event.tracing():
> + # RECLAIM_WB_ANON 0x1
> + # RECLAIM_WB_FILE 0x2
> + # RECLAIM_WB_SYNC 0x4
> + # RECLAIM_WB_ASYNC 0x8
> + _type = (flags & 0x2) >> 1
> + _io = (flags & 0x4) >> 2
> +
> + event.process_writepage(lru[_type], sync_io[_io])
> +
> + @classmethod
Space indentation on line above. For python3 this results in:
File "tools/perf/scripts/python/page-reclaim.py", line 217
@classmethod
^
TabError: inconsistent use of tabs and spaces in indentation
> + def iterate_proc(cls):
> + if show_opt != Show.DEFAULT:
> + print("\nPer process latency (ms):")
> + print_proc_latency(latency_metric, 'pid', '[comm]')
> +
> + if show_opt == Show.VERBOSE:
> + print("%20s %s" % ('timestamp','latency(ns)'))
Thanks
Tony
On Thu, Sep 26, 2019 at 11:36 AM Tony Jones <[email protected]> wrote:
>
> On 9/25/19 6:56 PM, Tony Jones wrote:
> > On 9/18/19 7:38 AM, Yafang Shao wrote:
> >> A new perf script page-reclaim is introduced in this patch. This new script
> >> is used to report the page reclaim details. The possible usage of this
> >> script is as bellow,
> >> - identify latency spike caused by direct reclaim
> >> - whehter the latency spike is relevant with pageout
> >> - why is page reclaim requested, i.e. whether it is because of memory
> >> fragmentation
> >> - page reclaim efficiency
> >> etc
> >> In the future we may also enhance it to analyze the memcg reclaim.
> >>
> >> Bellow is how to use this script,
> >> # Record, one of the following
> >> $ perf record -e 'vmscan:mm_vmscan_*' ./workload
> >> $ perf script record page-reclaim
> >>
> >> # Report
> >> $ perf script report page-reclaim
> >>
> >> # Report per process latency
> >> $ perf script report page-reclaim -- -p
> >
> >
> > I tested it with global-dhp__pagereclaim-performance from mmtests and got what appears to be reasonable results and the output looks correct and useful. However I'm not a vm expert so I can't comment further. Hopefully someone on linux-mm can give more specific feedback.
> >
> > There is one issue with Python3, see below. I didn't test with Python2.
>
> Ok, I guess this wasn't actually tested with Python3 as itervalues() is Python2 only. Any scripts need to work with both Python2.6+ and Python3.
>
> # perf script -i /tmp/perf.out -s page-reclaim.py -- -p
> ...
>
> Traceback (most recent call last):
> File "page-reclaim.py", line 305, in trace_end
> i.display_proc(),
> File "page-reclaim.py", line 268, in display_proc
> print_proc_latency(sorted(self.stat.stats['latency'].itervalues(),
> AttributeError: 'dict' object has no attribute 'itervalues'
> Fatal Python error: problem in Python trace event handler
>
> Use a try/except to handle this.
>
Hi Tony,
Thanks for your review.
I only verified it with python2.
I will improve it to make it work with both python2.6+ and python3.
Thanks
Yafang
On Thu, Sep 26, 2019 at 9:56 AM Tony Jones <[email protected]> wrote:
>
> On 9/18/19 7:38 AM, Yafang Shao wrote:
> > A new perf script page-reclaim is introduced in this patch. This new script
> > is used to report the page reclaim details. The possible usage of this
> > script is as bellow,
> > - identify latency spike caused by direct reclaim
> > - whehter the latency spike is relevant with pageout
> > - why is page reclaim requested, i.e. whether it is because of memory
> > fragmentation
> > - page reclaim efficiency
> > etc
> > In the future we may also enhance it to analyze the memcg reclaim.
> >
> > Bellow is how to use this script,
> > # Record, one of the following
> > $ perf record -e 'vmscan:mm_vmscan_*' ./workload
> > $ perf script record page-reclaim
> >
> > # Report
> > $ perf script report page-reclaim
> >
> > # Report per process latency
> > $ perf script report page-reclaim -- -p
>
>
> I tested it with global-dhp__pagereclaim-performance from mmtests and got what appears to be reasonable results and the output looks correct and useful. However I'm not a vm expert so I can't comment further. Hopefully someone on linux-mm can give more specific feedback.
>
+ Mel
Hi Mel,
This is motivated by
Documentation/trace/postprocess/trace-vmscan-postprocess.pl created by
you.
Could you pls. help take a look ?
Thanks
Yafang
> There is one issue with Python3, see below. I didn't test with Python2.
>
> >
> > + @classmethod
> > + def shrink_inactive(cls, pid, scanned, reclaimed, flags):
> > + event = cls.events.get(pid)
> > + if event and event.tracing():
> > + # RECLAIM_WB_ANON 0x1
> > + # RECLAIM_WB_FILE 0x2
> > + _type = (flags & 0x2) >> 1
> > + event.process_lru(lru[_type], scanned, reclaimed)
> > +
> > + @classmethod
> > + def writepage(cls, pid, flags):
> > + event = cls.events.get(pid)
> > + if event and event.tracing():
> > + # RECLAIM_WB_ANON 0x1
> > + # RECLAIM_WB_FILE 0x2
> > + # RECLAIM_WB_SYNC 0x4
> > + # RECLAIM_WB_ASYNC 0x8
> > + _type = (flags & 0x2) >> 1
> > + _io = (flags & 0x4) >> 2
> > +
> > + event.process_writepage(lru[_type], sync_io[_io])
> > +
> > + @classmethod
>
> Space indentation on line above. For python3 this results in:
>
> File "tools/perf/scripts/python/page-reclaim.py", line 217
> @classmethod
> ^
> TabError: inconsistent use of tabs and spaces in indentation
>
> > + def iterate_proc(cls):
> > + if show_opt != Show.DEFAULT:
> > + print("\nPer process latency (ms):")
> > + print_proc_latency(latency_metric, 'pid', '[comm]')
> > +
> > + if show_opt == Show.VERBOSE:
> > + print("%20s %s" % ('timestamp','latency(ns)'))
>
>
> Thanks
>
> Tony
>
On 9/25/19 6:56 PM, Tony Jones wrote:
> On 9/18/19 7:38 AM, Yafang Shao wrote:
>> A new perf script page-reclaim is introduced in this patch. This new script
>> is used to report the page reclaim details. The possible usage of this
>> script is as bellow,
>> - identify latency spike caused by direct reclaim
>> - whehter the latency spike is relevant with pageout
>> - why is page reclaim requested, i.e. whether it is because of memory
>> fragmentation
>> - page reclaim efficiency
>> etc
>> In the future we may also enhance it to analyze the memcg reclaim.
>>
>> Bellow is how to use this script,
>> # Record, one of the following
>> $ perf record -e 'vmscan:mm_vmscan_*' ./workload
>> $ perf script record page-reclaim
>>
>> # Report
>> $ perf script report page-reclaim
>>
>> # Report per process latency
>> $ perf script report page-reclaim -- -p
>
>
> I tested it with global-dhp__pagereclaim-performance from mmtests and got what appears to be reasonable results and the output looks correct and useful. However I'm not a vm expert so I can't comment further. Hopefully someone on linux-mm can give more specific feedback.
>
> There is one issue with Python3, see below. I didn't test with Python2.
Ok, I guess this wasn't actually tested with Python3 as itervalues() is Python2 only. Any scripts need to work with both Python2.6+ and Python3.
# perf script -i /tmp/perf.out -s page-reclaim.py -- -p
...
Traceback (most recent call last):
File "page-reclaim.py", line 305, in trace_end
i.display_proc(),
File "page-reclaim.py", line 268, in display_proc
print_proc_latency(sorted(self.stat.stats['latency'].itervalues(),
AttributeError: 'dict' object has no attribute 'itervalues'
Fatal Python error: problem in Python trace event handler
Use a try/except to handle this.
Thanks
Tony