Commit 442284a8 authored by Stephen Boyd's avatar Stephen Boyd Committed by Linus Torvalds

scripts/gdb: add a timer list command

Implement a command to print the timer list, much like how
/proc/timer_list is implemented.  This can be used to look at the
pending timers on a crashed system.

[swboyd@chromium.org: v2]
  Link: http://lkml.kernel.org/r/20190329220844.38234-5-swboyd@chromium.org
Link: http://lkml.kernel.org/r/20190325184522.260535-5-swboyd@chromium.orgSigned-off-by: default avatarStephen Boyd <swboyd@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Nikolay Borisov <n.borisov.lkml@gmail.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jackie Liu <liuyun01@kylinos.cn>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 449ca0c9
......@@ -13,8 +13,10 @@
*/
#include <linux/fs.h>
#include <linux/hrtimer.h>
#include <linux/mount.h>
#include <linux/of_fdt.h>
#include <linux/threads.h>
/* We need to stringify expanded macros so that they can be parsed */
......@@ -44,6 +46,9 @@ LX_VALUE(SB_DIRSYNC)
LX_VALUE(SB_NOATIME)
LX_VALUE(SB_NODIRATIME)
/* linux/htimer.h */
LX_GDBPARSED(hrtimer_resolution)
/* linux/mount.h */
LX_VALUE(MNT_NOSUID)
LX_VALUE(MNT_NODEV)
......@@ -52,8 +57,16 @@ LX_VALUE(MNT_NOATIME)
LX_VALUE(MNT_NODIRATIME)
LX_VALUE(MNT_RELATIME)
/* linux/threads.h */
LX_VALUE(NR_CPUS)
/* linux/of_fdt.h> */
LX_VALUE(OF_DT_HEADER)
/* Kernel Configs */
LX_CONFIG(CONFIG_GENERIC_CLOCKEVENTS)
LX_CONFIG(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
LX_CONFIG(CONFIG_HIGH_RES_TIMERS)
LX_CONFIG(CONFIG_NR_CPUS)
LX_CONFIG(CONFIG_OF)
LX_CONFIG(CONFIG_TICK_ONESHOT)
# SPDX-License-Identifier: GPL-2.0
#
# Copyright 2019 Google LLC.
import binascii
import gdb
from linux import constants
from linux import cpus
from linux import rbtree
from linux import utils
timerqueue_node_type = utils.CachedType("struct timerqueue_node").get_type()
hrtimer_type = utils.CachedType("struct hrtimer").get_type()
def ktime_get():
"""Returns the current time, but not very accurately
We can't read the hardware timer itself to add any nanoseconds
that need to be added since we last stored the time in the
timekeeper. But this is probably good enough for debug purposes."""
tk_core = gdb.parse_and_eval("&tk_core")
return tk_core['timekeeper']['tkr_mono']['base']
def print_timer(rb_node, idx):
timerqueue = utils.container_of(rb_node, timerqueue_node_type.pointer(),
"node")
timer = utils.container_of(timerqueue, hrtimer_type.pointer(), "node")
function = str(timer['function']).split(" ")[1].strip("<>")
softexpires = timer['_softexpires']
expires = timer['node']['expires']
now = ktime_get()
text = " #{}: <{}>, {}, ".format(idx, timer, function)
text += "S:{:02x}\n".format(int(timer['state']))
text += " # expires at {}-{} nsecs [in {} to {} nsecs]\n".format(
softexpires, expires, softexpires - now, expires - now)
return text
def print_active_timers(base):
curr = base['active']['next']['node']
curr = curr.address.cast(rbtree.rb_node_type.get_type().pointer())
idx = 0
while curr:
yield print_timer(curr, idx)
curr = rbtree.rb_next(curr)
idx += 1
def print_base(base):
text = " .base: {}\n".format(base.address)
text += " .index: {}\n".format(base['index'])
text += " .resolution: {} nsecs\n".format(constants.LX_hrtimer_resolution)
text += " .get_time: {}\n".format(base['get_time'])
if constants.LX_CONFIG_HIGH_RES_TIMERS:
text += " .offset: {} nsecs\n".format(base['offset'])
text += "active timers:\n"
text += "".join([x for x in print_active_timers(base)])
return text
def print_cpu(hrtimer_bases, cpu, max_clock_bases):
cpu_base = cpus.per_cpu(hrtimer_bases, cpu)
jiffies = gdb.parse_and_eval("jiffies_64")
tick_sched_ptr = gdb.parse_and_eval("&tick_cpu_sched")
ts = cpus.per_cpu(tick_sched_ptr, cpu)
text = "cpu: {}\n".format(cpu)
for i in xrange(max_clock_bases):
text += " clock {}:\n".format(i)
text += print_base(cpu_base['clock_base'][i])
if constants.LX_CONFIG_HIGH_RES_TIMERS:
fmts = [(" .{} : {} nsecs", 'expires_next'),
(" .{} : {}", 'hres_active'),
(" .{} : {}", 'nr_events'),
(" .{} : {}", 'nr_retries'),
(" .{} : {}", 'nr_hangs'),
(" .{} : {}", 'max_hang_time')]
text += "\n".join([s.format(f, cpu_base[f]) for s, f in fmts])
text += "\n"
if constants.LX_CONFIG_TICK_ONESHOT:
fmts = [(" .{} : {}", 'nohz_mode'),
(" .{} : {} nsecs", 'last_tick'),
(" .{} : {}", 'tick_stopped'),
(" .{} : {}", 'idle_jiffies'),
(" .{} : {}", 'idle_calls'),
(" .{} : {}", 'idle_sleeps'),
(" .{} : {} nsecs", 'idle_entrytime'),
(" .{} : {} nsecs", 'idle_waketime'),
(" .{} : {} nsecs", 'idle_exittime'),
(" .{} : {} nsecs", 'idle_sleeptime'),
(" .{}: {} nsecs", 'iowait_sleeptime'),
(" .{} : {}", 'last_jiffies'),
(" .{} : {}", 'next_timer'),
(" .{} : {} nsecs", 'idle_expires')]
text += "\n".join([s.format(f, ts[f]) for s, f in fmts])
text += "\njiffies: {}\n".format(jiffies)
text += "\n"
return text
def print_tickdevice(td, cpu):
dev = td['evtdev']
text = "Tick Device: mode: {}\n".format(td['mode'])
if cpu < 0:
text += "Broadcast device\n"
else:
text += "Per CPU device: {}\n".format(cpu)
text += "Clock Event Device: "
if dev == 0:
text += "<NULL>\n"
return text
text += "{}\n".format(dev['name'])
text += " max_delta_ns: {}\n".format(dev['max_delta_ns'])
text += " min_delta_ns: {}\n".format(dev['min_delta_ns'])
text += " mult: {}\n".format(dev['mult'])
text += " shift: {}\n".format(dev['shift'])
text += " mode: {}\n".format(dev['state_use_accessors'])
text += " next_event: {} nsecs\n".format(dev['next_event'])
text += " set_next_event: {}\n".format(dev['set_next_event'])
members = [('set_state_shutdown', " shutdown: {}\n"),
('set_state_periodic', " periodic: {}\n"),
('set_state_oneshot', " oneshot: {}\n"),
('set_state_oneshot_stopped', " oneshot stopped: {}\n"),
('tick_resume', " resume: {}\n")]
for member, fmt in members:
if dev[member]:
text += fmt.format(dev[member])
text += " event_handler: {}\n".format(dev['event_handler'])
text += " retries: {}\n".format(dev['retries'])
return text
def pr_cpumask(mask):
nr_cpu_ids = 1
if constants.LX_NR_CPUS > 1:
nr_cpu_ids = gdb.parse_and_eval("nr_cpu_ids")
inf = gdb.inferiors()[0]
bits = mask['bits']
num_bytes = (nr_cpu_ids + 7) / 8
buf = utils.read_memoryview(inf, bits, num_bytes).tobytes()
buf = binascii.b2a_hex(buf)
chunks = []
i = num_bytes
while i > 0:
i -= 1
start = i * 2
end = start + 2
chunks.append(buf[start:end])
if i != 0 and i % 4 == 0:
chunks.append(',')
extra = nr_cpu_ids % 8
if 0 < extra <= 4:
chunks[0] = chunks[0][0] # Cut off the first 0
return "".join(chunks)
class LxTimerList(gdb.Command):
"""Print /proc/timer_list"""
def __init__(self):
super(LxTimerList, self).__init__("lx-timerlist", gdb.COMMAND_DATA)
def invoke(self, arg, from_tty):
hrtimer_bases = gdb.parse_and_eval("&hrtimer_bases")
max_clock_bases = gdb.parse_and_eval("HRTIMER_MAX_CLOCK_BASES")
text = "Timer List Version: gdb scripts\n"
text += "HRTIMER_MAX_CLOCK_BASES: {}\n".format(max_clock_bases)
text += "now at {} nsecs\n".format(ktime_get())
for cpu in cpus.each_online_cpu():
text += print_cpu(hrtimer_bases, cpu, max_clock_bases)
if constants.LX_CONFIG_GENERIC_CLOCKEVENTS:
if constants.LX_CONFIG_GENERIC_CLOCKEVENTS_BROADCAST:
bc_dev = gdb.parse_and_eval("&tick_broadcast_device")
text += print_tickdevice(bc_dev, -1)
text += "\n"
mask = gdb.parse_and_eval("tick_broadcast_mask")
mask = pr_cpumask(mask)
text += "tick_broadcast_mask: {}\n".format(mask)
if constants.LX_CONFIG_TICK_ONESHOT:
mask = gdb.parse_and_eval("tick_broadcast_oneshot_mask")
mask = pr_cpumask(mask)
text += "tick_broadcast_oneshot_mask: {}\n".format(mask)
text += "\n"
tick_cpu_devices = gdb.parse_and_eval("&tick_cpu_device")
for cpu in cpus.each_online_cpu():
tick_dev = cpus.per_cpu(tick_cpu_devices, cpu)
text += print_tickdevice(tick_dev, cpu)
text += "\n"
gdb.write(text)
LxTimerList()
......@@ -33,3 +33,4 @@ else:
import linux.rbtree
import linux.proc
import linux.constants
import linux.timerlist
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment