MINOR: wdt: also consider that waiting in the thread dumper is normal

It happens that upon looping threads the watchdog fires, starts a dump,
and other threads expire their budget while waiting for the other threads
to get dumped and trigger a watchdog event again, adding some confusion
to the traces. With this patch the situation becomes clearer as we export
the list of threads being dumped so that the watchdog can check it before
deciding to trigger. This way such threads in queue for being dumped are
not attempted to be reported in turn.

This should be backported to 2.0 as it helps understand stack traces.
This commit is contained in:
Willy Tarreau 2019-07-31 19:20:39 +02:00
parent c07736209d
commit a37cb1880c
3 changed files with 7 additions and 4 deletions

View File

@ -70,6 +70,7 @@
struct task;
struct buffer;
extern volatile unsigned long threads_to_dump;
void ha_task_dump(struct buffer *buf, const struct task *task, const char *pfx);
void ha_thread_dump(struct buffer *buf, int thr, int calling_tid);
void ha_thread_dump_all_to_trash();

View File

@ -29,6 +29,11 @@
#include <proto/stream_interface.h>
#include <proto/task.h>
/* mask of threads still having to dump, used to respect ordering. Only used
* when USE_THREAD_DUMP is set.
*/
volatile unsigned long threads_to_dump = 0;
/* Dumps to the buffer some known information for the desired thread, and
* optionally extra info for the current thread. The dump will be appended to
* the buffer, so the caller is responsible for preliminary initializing it.
@ -404,9 +409,6 @@ void ha_thread_dump_all_to_trash()
*/
#define DEBUGSIG SIGURG
/* mask of threads still having to dump, used to respect ordering */
static volatile unsigned long threads_to_dump;
/* ID of the thread requesting the dump */
static unsigned int thread_dump_tid;

View File

@ -75,7 +75,7 @@ void wdt_handler(int sig, siginfo_t *si, void *arg)
if (n - p < 1000000000UL)
goto update_and_leave;
if ((threads_harmless_mask|sleeping_thread_mask) & (1UL << thr)) {
if ((threads_harmless_mask|sleeping_thread_mask|threads_to_dump) & (1UL << thr)) {
/* This thread is currently doing exactly nothing
* waiting in the poll loop (unlikely but possible),
* waiting for all other threads to join the rendez-vous