From a37cb1880c81b1f038e575d88ba7210aea0b7b8f Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Wed, 31 Jul 2019 19:20:39 +0200 Subject: [PATCH] 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. --- include/common/debug.h | 1 + src/debug.c | 8 +++++--- src/wdt.c | 2 +- 3 files changed, 7 insertions(+), 4 deletions(-) diff --git a/include/common/debug.h b/include/common/debug.h index 333203dd2..f43258e92 100644 --- a/include/common/debug.h +++ b/include/common/debug.h @@ -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(); diff --git a/src/debug.c b/src/debug.c index 9f538b660..0522f88bf 100644 --- a/src/debug.c +++ b/src/debug.c @@ -29,6 +29,11 @@ #include #include +/* 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; diff --git a/src/wdt.c b/src/wdt.c index 19d36c34d..aa89fd443 100644 --- a/src/wdt.c +++ b/src/wdt.c @@ -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