Edit: /usr/sbin/compactsnoop-bpfcc (11369B)
#! /usr/bin/python3
# @lint-avoid-python-3-compatibility-imports
#
# compactsnoop Trace compact zone and print details including issuing PID.
# For Linux, uses BCC, eBPF.
#
# This uses in-kernel eBPF maps to cache process details (PID and comm) by
# compact zone begin, as well as a starting timestamp for calculating
# latency.
#
# Copyright (c) 2019 Wenbo Zhang
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 11-NOV-2019 Wenbo Zhang Created this.
from __future__ import print_function
from bcc import BPF
import argparse
import platform
from datetime import datetime, timedelta
import sys
# arguments
examples = """examples:
./compactsnoop # trace all compact stall
./compactsnoop -T # include timestamps
./compactsnoop -d 10 # trace for 10 seconds only
./compactsnoop -K # output kernel stack trace
./compactsnoop -e # show extended fields
"""
parser = argparse.ArgumentParser(
description="Trace compact zone",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples,
)
parser.add_argument("-T", "--timestamp", action="store_true",
help="include timestamp on output")
parser.add_argument("-p", "--pid", help="trace this PID only")
parser.add_argument("-d", "--duration",
help="total duration of trace in seconds")
parser.add_argument("-K", "--kernel-stack", action="store_true",
help="output kernel stack trace")
parser.add_argument("-e", "--extended_fields", action="store_true",
help="show system memory state")
parser.add_argument("--ebpf", action="store_true", help=argparse.SUPPRESS)
args = parser.parse_args()
debug = 0
if args.duration:
args.duration = timedelta(seconds=int(args.duration))
NO_EXTENDED = """
#ifdef EXTNEDED_FIELDS
#undef EXTNEDED_FIELDS
#endif
"""
EXTENDED = """
#define EXTNEDED_FIELDS 1
"""
bpf_text = """
#include
#include
#include
#include
struct val_t {
int nid;
int idx;
int order;
int sync;
#ifdef EXTNEDED_FIELDS
int fragindex;
int low;
int min;
int high;
int free;
#endif
u64 ts; // compaction begin time
};
struct data_t {
u32 pid;
u32 tid;
int nid;
int idx;
int order;
u64 delta;
u64 ts; // compaction end time
int sync;
#ifdef EXTNEDED_FIELDS
int fragindex;
int low;
int min;
int high;
int free;
#endif
int status;
int stack_id;
char comm[TASK_COMM_LEN];
};
BPF_HASH(start, u64, struct val_t);
BPF_PERF_OUTPUT(events);
BPF_STACK_TRACE(stack_traces, 2048);
#ifdef CONFIG_NUMA
static inline int zone_to_nid_(struct zone *zone)
{
int node;
bpf_probe_read_kernel(&node, sizeof(node), &zone->node);
return node;
}
#else
static inline int zone_to_nid_(struct zone *zone)
{
return 0;
}
#endif
// #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
static inline int zone_idx_(struct zone *zone)
{
struct pglist_data *zone_pgdat = NULL;
bpf_probe_read_kernel(&zone_pgdat, sizeof(zone_pgdat), &zone->zone_pgdat);
return ((u64)zone - (u64)zone_pgdat->node_zones)/sizeof(struct zone);
}
#ifdef EXTNEDED_FIELDS
static inline void get_all_wmark_pages(struct zone *zone, struct val_t *valp)
{
u64 _watermark[NR_WMARK] = {};
u64 watermark_boost = 0;
bpf_probe_read_kernel(&_watermark, sizeof(_watermark), &zone->_watermark);
bpf_probe_read_kernel(&watermark_boost, sizeof(watermark_boost),
&zone->watermark_boost);
valp->min = _watermark[WMARK_MIN] + watermark_boost;
valp->low = _watermark[WMARK_LOW] + watermark_boost;
valp->high = _watermark[WMARK_HIGH] + watermark_boost;
bpf_probe_read_kernel(&valp->free, sizeof(valp->free),
&zone->vm_stat[NR_FREE_PAGES]);
}
#endif
static inline void submit_event(void *ctx, int status)
{
struct data_t data = {};
u64 ts = bpf_ktime_get_ns();
u64 id = bpf_get_current_pid_tgid();
struct val_t *valp = start.lookup(&id);
if (valp == NULL) {
// missed entry
return;
}
data.delta = ts - valp->ts;
data.ts = ts / 1000;
data.pid = id >> 32;
data.tid = id;
bpf_get_current_comm(&data.comm, sizeof(data.comm));
data.nid = valp->nid;
data.idx = valp->idx;
data.order = valp->order;
data.sync = valp->sync;
#ifdef EXTNEDED_FIELDS
data.fragindex = valp->fragindex;
data.min = valp->min;
data.low = valp->low;
data.high = valp->high;
data.free = valp->free;
#endif
data.status = status;
data.stack_id = stack_traces.get_stackid(ctx, 0);
events.perf_submit(ctx, &data, sizeof(data));
start.delete(&id);
}
#ifdef EXTNEDED_FIELDS
int trace_fragmentation_index_return(struct pt_regs *ctx)
{
struct val_t val = { };
int ret = PT_REGS_RC(ctx);
u64 id = bpf_get_current_pid_tgid();
PID_FILTER
val.fragindex = ret;
start.update(&id, &val);
return 0;
}
#endif
static inline void fill_compact_info(struct val_t *valp,
struct zone *zone,
int order)
{
valp->nid = zone_to_nid_(zone);
valp->idx = zone_idx_(zone);
valp->order = order;
}
RAW_TRACEPOINT_PROBE(mm_compaction_suitable)
{
// TP_PROTO(struct zone *zone, int order, int ret)
struct zone *zone = (struct zone *)ctx->args[0];
int order = (int)ctx->args[1];
int ret = (int)ctx->args[2];
u64 id;
if(ret != COMPACT_CONTINUE)
return 0;
id = bpf_get_current_pid_tgid();
PID_FILTER
#ifdef EXTNEDED_FIELDS
struct val_t *valp = start.lookup(&id);
if (valp == NULL) {
// missed entry or order <= PAGE_ALLOC_COSTLY_ORDER, eg:
// manual trigger echo 1 > /proc/sys/vm/compact_memory
struct val_t val = { .fragindex = -1000 };
valp = &val;
start.update(&id, valp);
}
fill_compact_info(valp, zone, order);
get_all_wmark_pages(zone, valp);
#else
struct val_t val = { };
fill_compact_info(&val, zone, order);
start.update(&id, &val);
#endif
return 0;
}
TRACEPOINT_PROBE(compaction, mm_compaction_begin)
{
bool sync = args->sync;
u64 id = bpf_get_current_pid_tgid();
struct val_t *valp = start.lookup(&id);
if (valp == NULL) {
// missed entry
return 0;
}
valp->ts = bpf_ktime_get_ns();
valp->sync = sync;
return 0;
}
TRACEPOINT_PROBE(compaction, mm_compaction_end)
{
submit_event(args, args->status);
return 0;
}
"""
if platform.machine() != 'x86_64' and platform.machine() != 'ppc64le':
print("""
Currently only support x86_64 and power servers, if you want
to use it on other platforms(including power embedded processors),
please refer include/linux/mmzone.h to modify zone_idex_to_str to
get the right zone type
""")
exit()
if args.extended_fields:
bpf_text = EXTENDED + bpf_text
else:
bpf_text = NO_EXTENDED + bpf_text
if args.pid:
bpf_text = bpf_text.replace("PID_FILTER",
"if (id >> 32 != %s) { return 0; }" % args.pid)
else:
bpf_text = bpf_text.replace("PID_FILTER", "")
if debug or args.ebpf:
print(bpf_text)
if args.ebpf:
exit()
# load BPF program
b = BPF(text=bpf_text)
if args.extended_fields:
b.attach_kretprobe(event="fragmentation_index",
fn_name="trace_fragmentation_index_return")
stack_traces = b.get_table("stack_traces")
initial_ts = 0
def zone_idx_to_str(idx):
# from include/linux/mmzone.h
# NOTICE: consider only x86_64 servers
zone_type = {
'x86_64':
{
0: "ZONE_DMA",
1: "ZONE_DMA32",
2: "ZONE_NORMAL"
},
# Zones in Power server only
'ppc64le':
{
0: "ZONE_NORMAL",
1: "ZONE_MOVABLE"
}
}
if idx in zone_type[platform.machine()]:
return zone_type[platform.machine()][idx]
else:
return str(idx)
def compact_result_to_str(status):
# from include/trace/evnets/mmflags.h
# from include/linux/compaction.h
compact_status = {
# COMPACT_NOT_SUITABLE_ZONE: For more detailed tracepoint
# output - internal to compaction
0: "not_suitable_zone",
# COMPACT_SKIPPED: compaction didn't start as it was not
# possible or direct reclaim was more suitable
1: "skipped",
# COMPACT_DEFERRED: compaction didn't start as it was
# deferred due to past failures
2: "deferred",
# COMPACT_NOT_SUITABLE_PAGE: For more detailed tracepoint
# output - internal to compaction
3: "no_suitable_page",
# COMPACT_CONTINUE: compaction should continue to another pageblock
4: "continue",
# COMPACT_COMPLETE: The full zone was compacted scanned but wasn't
# successful to compact suitable pages.
5: "complete",
# COMPACT_PARTIAL_SKIPPED: direct compaction has scanned part of the
# zone but wasn't successful to compact suitable pages.
6: "partial_skipped",
# COMPACT_CONTENDED: compaction terminated prematurely due to lock
# contentions
7: "contended",
# COMPACT_SUCCESS: direct compaction terminated after concluding
# that the allocation should now succeed
8: "success",
}
if status in compact_status:
return compact_status[status]
else:
return str(status)
# header
if args.timestamp:
print("%-14s" % ("TIME(s)"), end=" ")
print("%-14s %-6s %-4s %-12s %-5s %-7s" %
("COMM", "PID", "NODE", "ZONE", "ORDER", "MODE"), end=" ")
if args.extended_fields:
print("%-8s %-8s %-8s %-8s %-8s" %
("FRAGIDX", "MIN", "LOW", "HIGH", "FREE"), end=" ")
print("%9s %16s" % ("LAT(ms)", "STATUS"))
# process event
def print_event(cpu, data, size):
event = b["events"].event(data)
global initial_ts
if not initial_ts:
initial_ts = event.ts
if args.timestamp:
delta = event.ts - initial_ts
print("%-14.9f" % (float(delta) / 1000000), end=" ")
print("%-14.14s %-6s %-4s %-12s %-5s %-7s" % (
event.comm.decode("utf-8", "replace"),
event.pid,
event.nid,
zone_idx_to_str(event.idx),
event.order,
"SYNC" if event.sync else "ASYNC"), end=" ")
if args.extended_fields:
print("%-8.3f %-8s %-8s %-8s %-8s" % (
(float(event.fragindex) / 1000),
event.min, event.low, event.high, event.free
), end=" ")
print("%9.3f %16s" % (
float(event.delta) / 1000000, compact_result_to_str(event.status)))
if args.kernel_stack:
for addr in stack_traces.walk(event.stack_id):
sym = b.ksym(addr, show_offset=True)
print("\t%s" % sym)
print("")
sys.stdout.flush()
# loop with callback to print_event
b["events"].open_perf_buffer(print_event, page_cnt=64)
start_time = datetime.now()
while not args.duration or datetime.now() - start_time < args.duration:
try:
b.perf_buffer_poll()
except KeyboardInterrupt:
exit()