MINOR: debug: add a balance of alloc - free at the end of the memstats dump
When digging into suspected memory leaks, it's cumbersome to count the
number of allocations and free calls. Here we're adding a summary at the
end of the sum of allocs minus the sum of frees, excluding realloc since
we can't know how much it releases upon each call. This means that when
doing many realloc+free the count may be negative but in practice there
are very few reallocs so that's not a problem. Also the size/call is signed
and corresponds to the average size allocated (e.g. leaked) per call.
It seems to work reasonably well for now:
> debug dev memstats match buf
quic_conn.c:2978 P_FREE size: 1239547904 calls: 75656 size/call: 16384 buffer
quic_conn.c:2960 P_ALLOC size: 1239547904 calls: 75656 size/call: 16384 buffer
mux_quic.c:393 P_ALLOC size: 9112780800 calls: 556200 size/call: 16384 buffer
mux_quic.c:383 P_ALLOC size: 17783193600 calls: 1085400 size/call: 16384 buffer
mux_quic.c:159 P_FREE size: 8935833600 calls: 545400 size/call: 16384 buffer
mux_quic.c:142 P_FREE size: 9112780800 calls: 556200 size/call: 16384 buffer
h3.c:776 P_ALLOC size: 8935833600 calls: 545400 size/call: 16384 buffer
quic_stream.c:166 P_FREE size: 975241216 calls: 59524 size/call: 16384 buffer
quic_stream.c:127 P_FREE size: 7960592384 calls: 485876 size/call: 16384 buffer
stream.c:772 P_FREE size: 8798208 calls: 537 size/call: 16384 buffer
stream.c:768 P_FREE size: 2424832 calls: 148 size/call: 16384 buffer
stream.c:751 P_ALLOC size: 8852062208 calls: 540287 size/call: 16384 buffer
stream.c:641 P_FREE size: 8849162240 calls: 540110 size/call: 16384 buffer
stream.c:640 P_FREE size: 8847360000 calls: 540000 size/call: 16384 buffer
channel.h:850 P_ALLOC size: 2441216 calls: 149 size/call: 16384 buffer
channel.h:850 P_ALLOC size: 5914624 calls: 361 size/call: 16384 buffer
dynbuf.c:55 P_FREE size: 32768 calls: 2 size/call: 16384 buffer
Total BALANCE size: 0 calls: 5606906 size/call: 0 (excl. realloc)
Let's see how useful this becomes over time.
diff --git a/src/debug.c b/src/debug.c
index 8868797..ba39630 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -1239,7 +1239,9 @@
struct mem_stats *start, *stop; /* begin/end of dump */
char *match; /* non-null if a name prefix is specified */
int show_all; /* show all entries if non-null */
- int width;
+ int width; /* 1st column width */
+ long tot_size; /* sum of alloc-free */
+ ulong tot_calls; /* sum of calls */
};
/* CLI parser for the "debug dev memstats" command. Sets a dev_mem_ctx shown above. */
@@ -1341,6 +1343,7 @@
const char *p;
const char *info = NULL;
const char *func = NULL;
+ int direction = 0; // neither alloc nor free (e.g. realloc)
if (!ptr->size && !ptr->calls && !ctx->show_all)
continue;
@@ -1354,13 +1357,13 @@
func = ptr->caller.func;
switch (ptr->caller.what) {
- case MEM_STATS_TYPE_CALLOC: type = "CALLOC"; break;
- case MEM_STATS_TYPE_FREE: type = "FREE"; break;
- case MEM_STATS_TYPE_MALLOC: type = "MALLOC"; break;
+ case MEM_STATS_TYPE_CALLOC: type = "CALLOC"; direction = 1; break;
+ case MEM_STATS_TYPE_FREE: type = "FREE"; direction = -1; break;
+ case MEM_STATS_TYPE_MALLOC: type = "MALLOC"; direction = 1; break;
case MEM_STATS_TYPE_REALLOC: type = "REALLOC"; break;
- case MEM_STATS_TYPE_STRDUP: type = "STRDUP"; break;
- case MEM_STATS_TYPE_P_ALLOC: type = "P_ALLOC"; if (ptr->extra) info = ((const struct pool_head *)ptr->extra)->name; break;
- case MEM_STATS_TYPE_P_FREE: type = "P_FREE"; if (ptr->extra) info = ((const struct pool_head *)ptr->extra)->name; break;
+ case MEM_STATS_TYPE_STRDUP: type = "STRDUP"; direction = 1; break;
+ case MEM_STATS_TYPE_P_ALLOC: type = "P_ALLOC"; direction = 1; if (ptr->extra) info = ((const struct pool_head *)ptr->extra)->name; break;
+ case MEM_STATS_TYPE_P_FREE: type = "P_FREE"; direction = -1; if (ptr->extra) info = ((const struct pool_head *)ptr->extra)->name; break;
default: type = "UNSET"; break;
}
@@ -1395,10 +1398,35 @@
if (applet_putchk(appctx, &trash) == -1) {
ctx->start = ptr;
ret = 0;
- break;
+ goto end;
+ }
+ if (direction > 0) {
+ ctx->tot_size += (ulong)ptr->size;
+ ctx->tot_calls += (ulong)ptr->calls;
+ }
+ else if (direction < 0) {
+ ctx->tot_size -= (ulong)ptr->size;
+ ctx->tot_calls += (ulong)ptr->calls;
}
}
+ /* now dump a summary */
+ chunk_reset(&trash);
+ chunk_appendf(&trash, "Total");
+ while (trash.data < ctx->width)
+ trash.area[trash.data++] = ' ';
+
+ chunk_appendf(&trash, "%7s size: %12ld calls: %9lu size/call: %6ld %s\n",
+ "BALANCE",
+ ctx->tot_size, ctx->tot_calls,
+ (long)(ctx->tot_calls ? (ctx->tot_size / ctx->tot_calls) : 0),
+ "(excl. realloc)");
+
+ if (applet_putchk(appctx, &trash) == -1) {
+ ctx->start = ptr;
+ ret = 0;
+ goto end;
+ }
end:
return ret;
}