Commit 78a947f5 authored by Trond Myklebust's avatar Trond Myklebust Committed by Chuck Lever
Browse files

sunrpc: Add tracing for cache events 



Add basic tracing for debugging the sunrpc cache events.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 277f27e2

include/trace/events/sunrpc.h

+33 −0
Original line number Diff line number Diff line
@@ -1335,6 +1335,39 @@ DECLARE_EVENT_CLASS(svc_deferred_event, 
DEFINE_SVC_DEFERRED_EVENT(drop);

DEFINE_SVC_DEFERRED_EVENT(revisit);



DECLARE_EVENT_CLASS(cache_event,

	TP_PROTO(

		const struct cache_detail *cd,

		const struct cache_head *h

	),



	TP_ARGS(cd, h),



	TP_STRUCT__entry(

		__field(const struct cache_head *, h)

		__string(name, cd->name)

	),



	TP_fast_assign(

		__entry->h = h;

		__assign_str(name, cd->name);

	),



	TP_printk("cache=%s entry=%p", __get_str(name), __entry->h)

);

#define DEFINE_CACHE_EVENT(name) \

	DEFINE_EVENT(cache_event, name, \

			TP_PROTO( \

				const struct cache_detail *cd, \

				const struct cache_head *h \

			), \

			TP_ARGS(cd, h))

DEFINE_CACHE_EVENT(cache_entry_expired);

DEFINE_CACHE_EVENT(cache_entry_upcall);

DEFINE_CACHE_EVENT(cache_entry_update);

DEFINE_CACHE_EVENT(cache_entry_make_negative);

DEFINE_CACHE_EVENT(cache_entry_no_listener);



#endif /* _TRACE_SUNRPC_H */



#include <trace/define_trace.h>

net/sunrpc/cache.c

+27 −9
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
#include <linux/sunrpc/cache.h>

#include <linux/sunrpc/stats.h>

#include <linux/sunrpc/rpc_pipe_fs.h>

#include <trace/events/sunrpc.h>

#include "netns.h"



#define	 RPCDBG_FACILITY RPCDBG_CACHE
@@ -120,6 +121,7 @@ static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail, 
		if (test_bit(CACHE_VALID, &tmp->flags) &&

		    cache_is_expired(detail, tmp)) {

			sunrpc_begin_cache_remove_entry(tmp, detail);

			trace_cache_entry_expired(detail, tmp);

			freeme = tmp;

			break;

		}
@@ -176,6 +178,25 @@ static void cache_fresh_unlocked(struct cache_head *head, 
	}

}



static void cache_make_negative(struct cache_detail *detail,

				struct cache_head *h)

{

	set_bit(CACHE_NEGATIVE, &h->flags);

	trace_cache_entry_make_negative(detail, h);

}



static void cache_entry_update(struct cache_detail *detail,

			       struct cache_head *h,

			       struct cache_head *new)

{

	if (!test_bit(CACHE_NEGATIVE, &new->flags)) {

		detail->update(h, new);

		trace_cache_entry_update(detail, h);

	} else {

		cache_make_negative(detail, h);

	}

}



struct cache_head *sunrpc_cache_update(struct cache_detail *detail,

				       struct cache_head *new, struct cache_head *old, int hash)

{
@@ -188,10 +209,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, 
	if (!test_bit(CACHE_VALID, &old->flags)) {

		spin_lock(&detail->hash_lock);

		if (!test_bit(CACHE_VALID, &old->flags)) {

			if (test_bit(CACHE_NEGATIVE, &new->flags))

				set_bit(CACHE_NEGATIVE, &old->flags);

			else

				detail->update(old, new);

			cache_entry_update(detail, old, new);

			cache_fresh_locked(old, new->expiry_time, detail);

			spin_unlock(&detail->hash_lock);

			cache_fresh_unlocked(old, detail);
@@ -209,10 +227,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, 
	detail->init(tmp, old);



	spin_lock(&detail->hash_lock);

	if (test_bit(CACHE_NEGATIVE, &new->flags))

		set_bit(CACHE_NEGATIVE, &tmp->flags);

	else

		detail->update(tmp, new);

	cache_entry_update(detail, tmp, new);

	hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]);

	detail->entries++;

	cache_get(tmp);
@@ -254,7 +269,7 @@ static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h 
	spin_lock(&detail->hash_lock);

	rv = cache_is_valid(h);

	if (rv == -EAGAIN) {

		set_bit(CACHE_NEGATIVE, &h->flags);

		cache_make_negative(detail, h);

		cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY,

				   detail);

		rv = -ENOENT;
@@ -460,6 +475,7 @@ static int cache_clean(void) 
				continue;



			sunrpc_begin_cache_remove_entry(ch, current_detail);

			trace_cache_entry_expired(current_detail, ch);

			rv = 1;

			break;

		}
@@ -1215,6 +1231,7 @@ static int cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h) 
	if (test_bit(CACHE_PENDING, &h->flags)) {

		crq->item = cache_get(h);

		list_add_tail(&crq->q.list, &detail->queue);

		trace_cache_entry_upcall(detail, h);

	} else

		/* Lost a race, no longer PENDING, so don't enqueue */

		ret = -EAGAIN;
@@ -1240,6 +1257,7 @@ int sunrpc_cache_pipe_upcall_timeout(struct cache_detail *detail, 
{

	if (!cache_listeners_exist(detail)) {

		warn_no_listener(detail);

		trace_cache_entry_no_listener(detail, h);

		return -EINVAL;

	}

	return sunrpc_cache_pipe_upcall(detail, h);