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ddb(4): Add 'show badstacks' command to show witness badstacks

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Add a DDB command that mirrors sysctl debug.witness.badstacks.

Reapply r323935 after fixing trivial deficiency.  I forgot to compile with
WITNESS enabled.  Thanks emaste@ for fixing the build while I was asleep.

Reported by:	rstone
Reviewed by:	rstone (previous version)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D12468
This commit is contained in:
Conrad Meyer 2017-09-23 17:48:49 +00:00
parent 59059cda6a
commit f41b85a63c
1 changed files with 49 additions and 19 deletions
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68
sys/kern/subr_witness.c
View File

@ -2539,31 +2539,18 @@ DB_SHOW_COMMAND(witness, db_witness_display)
} }
#endif #endif
static int static void
sysctl_debug_witness_badstacks(SYSCTL_HANDLER_ARGS) sbuf_print_witness_badstacks(struct sbuf *sb, size_t *oldidx)
{ {
struct witness_lock_order_data *data1, *data2, *tmp_data1, *tmp_data2; struct witness_lock_order_data *data1, *data2, *tmp_data1, *tmp_data2;
struct witness *tmp_w1, *tmp_w2, *w1, *w2; struct witness *tmp_w1, *tmp_w2, *w1, *w2;
struct sbuf *sb;
u_int w_rmatrix1, w_rmatrix2; u_int w_rmatrix1, w_rmatrix2;
int error, generation, i, j; int generation, i, j;
tmp_data1 = NULL; tmp_data1 = NULL;
tmp_data2 = NULL; tmp_data2 = NULL;
tmp_w1 = NULL; tmp_w1 = NULL;
tmp_w2 = NULL; tmp_w2 = NULL;
if (witness_watch < 1) {
error = SYSCTL_OUT(req, w_notrunning, sizeof(w_notrunning));
return (error);
}
if (witness_cold) {
error = SYSCTL_OUT(req, w_stillcold, sizeof(w_stillcold));
return (error);
}
error = 0;
sb = sbuf_new(NULL, NULL, badstack_sbuf_size, SBUF_AUTOEXTEND);
if (sb == NULL)
return (ENOMEM);
/* Allocate and init temporary storage space. */ /* Allocate and init temporary storage space. */
tmp_w1 = malloc(sizeof(struct witness), M_TEMP, M_WAITOK | M_ZERO); tmp_w1 = malloc(sizeof(struct witness), M_TEMP, M_WAITOK | M_ZERO);
@ -2587,7 +2574,7 @@ restart:
mtx_unlock_spin(&w_mtx); mtx_unlock_spin(&w_mtx);
/* The graph has changed, try again. */ /* The graph has changed, try again. */
req->oldidx = 0; *oldidx = 0;
sbuf_clear(sb); sbuf_clear(sb);
goto restart; goto restart;
} }
@ -2613,7 +2600,7 @@ restart:
mtx_unlock_spin(&w_mtx); mtx_unlock_spin(&w_mtx);
/* The graph has changed, try again. */ /* The graph has changed, try again. */
req->oldidx = 0; *oldidx = 0;
sbuf_clear(sb); sbuf_clear(sb);
goto restart; goto restart;
} }
@ -2672,7 +2659,7 @@ restart:
* The graph changed while we were printing stack data, * The graph changed while we were printing stack data,
* try again. * try again.
*/ */
req->oldidx = 0; *oldidx = 0;
sbuf_clear(sb); sbuf_clear(sb);
goto restart; goto restart;
} }
@ -2683,6 +2670,28 @@ restart:
free(tmp_data2, M_TEMP); free(tmp_data2, M_TEMP);
free(tmp_w1, M_TEMP); free(tmp_w1, M_TEMP);
free(tmp_w2, M_TEMP); free(tmp_w2, M_TEMP);
}
static int
sysctl_debug_witness_badstacks(SYSCTL_HANDLER_ARGS)
{
struct sbuf *sb;
int error;
if (witness_watch < 1) {
error = SYSCTL_OUT(req, w_notrunning, sizeof(w_notrunning));
return (error);
}
if (witness_cold) {
error = SYSCTL_OUT(req, w_stillcold, sizeof(w_stillcold));
return (error);
}
error = 0;
sb = sbuf_new(NULL, NULL, badstack_sbuf_size, SBUF_AUTOEXTEND);
if (sb == NULL)
return (ENOMEM);
sbuf_print_witness_badstacks(sb, &req->oldidx);
sbuf_finish(sb); sbuf_finish(sb);
error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1);
@ -2691,6 +2700,27 @@ restart:
return (error); return (error);
} }
#ifdef DDB
static int
sbuf_db_printf_drain(void *arg __unused, const char *data, int len)
{
return (db_printf("%.*s", len, data));
}
DB_SHOW_COMMAND(badstacks, db_witness_badstacks)
{
struct sbuf sb;
char buffer[128];
size_t dummy;
sbuf_new(&sb, buffer, sizeof(buffer), SBUF_FIXEDLEN);
sbuf_set_drain(&sb, sbuf_db_printf_drain, NULL);
sbuf_print_witness_badstacks(&sb, &dummy);
sbuf_finish(&sb);
}
#endif
static int static int
sysctl_debug_witness_channel(SYSCTL_HANDLER_ARGS) sysctl_debug_witness_channel(SYSCTL_HANDLER_ARGS)
{ {