bcache: Fix/revamp tracepoints
The tracepoints were reworked to be more sensible, and fixed a null
pointer deref in one of the tracepoints.
Converted some of the pr_debug()s to tracepoints - this is partly a
performance optimization; it used to be that with DEBUG or
CONFIG_DYNAMIC_DEBUG pr_debug() was an empty macro; but at some point it
was changed to an empty inline function.
Some of the pr_debug() statements had rather expensive function calls as
part of the arguments, so this code was getting run unnecessarily even
on non debug kernels - in some fast paths, too.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c
index 38428f4..b54b73b 100644
--- a/drivers/md/bcache/alloc.c
+++ b/drivers/md/bcache/alloc.c
@@ -65,6 +65,7 @@
#include <linux/kthread.h>
#include <linux/random.h>
+#include <trace/events/bcache.h>
#define MAX_IN_FLIGHT_DISCARDS 8U
@@ -351,10 +352,7 @@
break;
}
- pr_debug("free %zu/%zu free_inc %zu/%zu unused %zu/%zu",
- fifo_used(&ca->free), ca->free.size,
- fifo_used(&ca->free_inc), ca->free_inc.size,
- fifo_used(&ca->unused), ca->unused.size);
+ trace_bcache_alloc_invalidate(ca);
}
#define allocator_wait(ca, cond) \
@@ -473,9 +471,7 @@
return r;
}
- pr_debug("alloc failure: blocked %i free %zu free_inc %zu unused %zu",
- atomic_read(&ca->set->prio_blocked), fifo_used(&ca->free),
- fifo_used(&ca->free_inc), fifo_used(&ca->unused));
+ trace_bcache_alloc_fail(ca);
if (cl) {
closure_wait(&ca->set->bucket_wait, cl);