diff mbox series

[v2,14/23] mm/slab_common: print cache name in tracepoints

Message ID 20220414085727.643099-15-42.hyeyoo@gmail.com (mailing list archive)
State New
Headers show
Series common kmalloc for SLUB and SLAB v2 | expand

Commit Message

Hyeonggon Yoo April 14, 2022, 8:57 a.m. UTC 
Print cache name in tracepoints. If there is no corresponding cache
(kmalloc in SLOB or kmalloc_large_node), use KMALLOC_{,LARGE_}NAME
macro.

Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
---
 include/trace/events/kmem.h | 34 +++++++++++++++++++---------------
 mm/slab.c                   |  9 +++++----
 mm/slab.h                   |  4 ++++
 mm/slab_common.c            |  6 ++----
 mm/slob.c                   | 10 +++++-----
 mm/slub.c                   | 10 +++++-----
 6 files changed, 40 insertions(+), 33 deletions(-)

Comments

Vlastimil Babka April 29, 2022, 2:05 p.m. UTC | #1 
On 4/14/22 10:57, Hyeonggon Yoo wrote:
> Print cache name in tracepoints. If there is no corresponding cache
> (kmalloc in SLOB or kmalloc_large_node), use KMALLOC_{,LARGE_}NAME
> macro.
> 
> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>

Regarding tracepoints, I'm not sure it's a good idea to unify kmalloc and
kmem_cache_alloc. I think the common use case is to trace kmalloc as there
are many different callers, and then I'm not interested in kmem_cache_alloc
callers much.

What I would suggest instead is:
- drop the _node versions, add node to normal versions
- drop the kmem_alloc EVENT_CLASS, as kmalloc is different enough from
kmem_cache_alloc (see next points), define separately as TRACE_EVENT().
- printing cache_name makes sense to add for kmem_cache_alloc (also allows
filtering events) but not for kmalloc.
- kmem_cache_alloc with name can then drop the bytes_req, bytes_alloc as
they are fixed for given name (and can be read from slabinfo).

Not using a common tracepoint will prevent some later unifications/cleanup
(patch 21?), but hopefully not too much?
Hyeonggon Yoo April 30, 2022, 2:06 p.m. UTC | #2 
On Fri, Apr 29, 2022 at 04:05:14PM +0200, Vlastimil Babka wrote:
> On 4/14/22 10:57, Hyeonggon Yoo wrote:
> > Print cache name in tracepoints. If there is no corresponding cache
> > (kmalloc in SLOB or kmalloc_large_node), use KMALLOC_{,LARGE_}NAME
> > macro.
> > 
> > Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
> 
> Regarding tracepoints, I'm not sure it's a good idea to unify kmalloc and
> kmem_cache_alloc. I think the common use case is to trace kmalloc as there
> are many different callers, and then I'm not interested in kmem_cache_alloc
> callers much.

Make sense.

> What I would suggest instead is:
> - drop the _node versions, add node to normal versions
> - drop the kmem_alloc EVENT_CLASS, as kmalloc is different enough from
> kmem_cache_alloc (see next points), define separately as TRACE_EVENT().
> - printing cache_name makes sense to add for kmem_cache_alloc (also allows
> filtering events) but not for kmalloc.
> - kmem_cache_alloc with name can then drop the bytes_req, bytes_alloc as
> they are fixed for given name (and can be read from slabinfo).

Those suggestions makes sense to me.
kmalloc and kmem_cache_alloc are a bit different.

> Not using a common tracepoint will prevent some later unifications/cleanup
> (patch 21?), but hopefully not too much?

In v2 unification of __kmalloc_node()/kfree() somewhat depends on unified tracepoint.
I'll try to unify them with this approach in v3.
diff mbox series

Patch

diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index ddc8c944f417..35e6887c6101 100644
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -61,16 +61,18 @@  DEFINE_EVENT(kmem_alloc, kmem_cache_alloc,
 
 DECLARE_EVENT_CLASS(kmem_alloc_node,
 
-	TP_PROTO(unsigned long call_site,
+	TP_PROTO(const char *name,
+		 unsigned long call_site,
 		 const void *ptr,
 		 size_t bytes_req,
 		 size_t bytes_alloc,
 		 gfp_t gfp_flags,
 		 int node),
 
-	TP_ARGS(call_site, ptr, bytes_req, bytes_alloc, gfp_flags, node),
+	TP_ARGS(name, call_site, ptr, bytes_req, bytes_alloc, gfp_flags, node),
 
 	TP_STRUCT__entry(
+		__string(	name,		name		)
 		__field(	unsigned long,	call_site	)
 		__field(	const void *,	ptr		)
 		__field(	size_t,		bytes_req	)
@@ -80,6 +82,7 @@  DECLARE_EVENT_CLASS(kmem_alloc_node,
 	),
 
 	TP_fast_assign(
+		__assign_str(name, name);
 		__entry->call_site	= call_site;
 		__entry->ptr		= ptr;
 		__entry->bytes_req	= bytes_req;
@@ -88,7 +91,8 @@  DECLARE_EVENT_CLASS(kmem_alloc_node,
 		__entry->node		= node;
 	),
 
-	TP_printk("call_site=%pS ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s node=%d",
+	TP_printk("name=%s call_site=%pS ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s node=%d",
+		__get_str(name),
 		(void *)__entry->call_site,
 		__entry->ptr,
 		__entry->bytes_req,
@@ -99,20 +103,20 @@  DECLARE_EVENT_CLASS(kmem_alloc_node,
 
 DEFINE_EVENT(kmem_alloc_node, kmalloc_node,
 
-	TP_PROTO(unsigned long call_site, const void *ptr,
-		 size_t bytes_req, size_t bytes_alloc,
+	TP_PROTO(const char *name, unsigned long call_site,
+		 const void *ptr, size_t bytes_req, size_t bytes_alloc,
 		 gfp_t gfp_flags, int node),
 
-	TP_ARGS(call_site, ptr, bytes_req, bytes_alloc, gfp_flags, node)
+	TP_ARGS(name, call_site, ptr, bytes_req, bytes_alloc, gfp_flags, node)
 );
 
 DEFINE_EVENT(kmem_alloc_node, kmem_cache_alloc_node,
 
-	TP_PROTO(unsigned long call_site, const void *ptr,
-		 size_t bytes_req, size_t bytes_alloc,
+	TP_PROTO(const char *name, unsigned long call_site,
+		 const void *ptr, size_t bytes_req, size_t bytes_alloc,
 		 gfp_t gfp_flags, int node),
 
-	TP_ARGS(call_site, ptr, bytes_req, bytes_alloc, gfp_flags, node)
+	TP_ARGS(name, call_site, ptr, bytes_req, bytes_alloc, gfp_flags, node)
 );
 
 TRACE_EVENT(kfree,
@@ -137,24 +141,24 @@  TRACE_EVENT(kfree,
 
 TRACE_EVENT(kmem_cache_free,
 
-	TP_PROTO(unsigned long call_site, const void *ptr, const char *name),
+	TP_PROTO(const char *name, unsigned long call_site, const void *ptr),
 
-	TP_ARGS(call_site, ptr, name),
+	TP_ARGS(name, call_site, ptr),
 
 	TP_STRUCT__entry(
+		__string(	name,	name	)
 		__field(	unsigned long,	call_site	)
 		__field(	const void *,	ptr		)
-		__string(	name,	name	)
 	),
 
 	TP_fast_assign(
+		__assign_str(name, name);
 		__entry->call_site	= call_site;
 		__entry->ptr		= ptr;
-		__assign_str(name, name);
 	),
 
-	TP_printk("call_site=%pS ptr=%p name=%s",
-		  (void *)__entry->call_site, __entry->ptr, __get_str(name))
+	TP_printk("name=%s call_site=%pS ptr=%p",
+		  __get_str(name), (void *)__entry->call_site, __entry->ptr)
 );
 
 TRACE_EVENT(mm_page_free,
diff --git a/mm/slab.c b/mm/slab.c
index 1dfe0f9d5882..3c47d0979706 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3448,8 +3448,9 @@  void *__kmem_cache_alloc_node(struct kmem_cache *cachep, struct list_lru *lru,
 	void *ret = slab_alloc_node(cachep, lru, flags, nodeid,
 				    cachep->object_size, caller);
 
-	trace_kmem_cache_alloc_node(caller, ret, cachep->object_size,
-				    cachep->size, flags, nodeid);
+	trace_kmem_cache_alloc_node(cachep->name, caller, ret,
+				    cachep->object_size, cachep->size,
+				    flags, nodeid);
 
 	return ret;
 }
@@ -3518,7 +3519,7 @@  void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
 	ret = slab_alloc_node(cachep, NULL, flags, nodeid, size, _RET_IP_);
 
 	ret = kasan_kmalloc(cachep, ret, size, flags);
-	trace_kmalloc_node(_RET_IP_, ret,
+	trace_kmalloc_node(cachep->name, _RET_IP_, ret,
 			   size, cachep->size,
 			   flags, nodeid);
 	return ret;
@@ -3593,7 +3594,7 @@  void kmem_cache_free(struct kmem_cache *cachep, void *objp)
 	if (!cachep)
 		return;
 
-	trace_kmem_cache_free(_RET_IP_, objp, cachep->name);
+	trace_kmem_cache_free(cachep->name, _RET_IP_, objp);
 	local_irq_save(flags);
 	debug_check_no_locks_freed(objp, cachep->object_size);
 	if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
diff --git a/mm/slab.h b/mm/slab.h
index b864c5bc4c25..45ddb19df319 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -275,6 +275,10 @@  void create_kmalloc_caches(slab_flags_t);
 struct kmem_cache *kmalloc_slab(size_t, gfp_t);
 #endif
 
+/* cache names for tracepoints where it has no corresponding cache  */
+#define KMALLOC_LARGE_NAME "kmalloc_large_node"
+#define KMALLOC_NAME "kmalloc_node"
+
 gfp_t kmalloc_fix_flags(gfp_t flags);
 
 /* Functions provided by the slab allocators */
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 960cc07c3a91..416f0a1f17a6 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -956,10 +956,8 @@  void *kmalloc_large_node(size_t size, gfp_t flags, int node)
 	ptr = kasan_kmalloc_large(ptr, size, flags);
 	/* As ptr might get tagged, call kmemleak hook after KASAN. */
 	kmemleak_alloc(ptr, size, 1, flags);
-	trace_kmalloc_node(_RET_IP_, ptr,
-			   size, PAGE_SIZE << order,
-			   flags, node);
-
+	trace_kmalloc_node(KMALLOC_LARGE_NAME, _RET_IP_, ptr, size,
+			   PAGE_SIZE << order, flags, node);
 	return ptr;
 }
 EXPORT_SYMBOL(kmalloc_large_node);
diff --git a/mm/slob.c b/mm/slob.c
index 6c7c30845056..8abde6037d95 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -505,7 +505,7 @@  __do_kmalloc_node(size_t size, gfp_t gfp, int node, unsigned long caller)
 		*m = size;
 		ret = (void *)m + minalign;
 
-		trace_kmalloc_node(caller, ret,
+		trace_kmalloc_node(KMALLOC_NAME, caller, ret,
 				   size, size + minalign, gfp, node);
 	} else {
 		unsigned int order = get_order(size);
@@ -514,7 +514,7 @@  __do_kmalloc_node(size_t size, gfp_t gfp, int node, unsigned long caller)
 			gfp |= __GFP_COMP;
 		ret = slob_new_pages(gfp, order, node);
 
-		trace_kmalloc_node(caller, ret,
+		trace_kmalloc_node(KMALLOC_LARGE_NAME, caller, ret,
 				   size, PAGE_SIZE << order, gfp, node);
 	}
 
@@ -597,12 +597,12 @@  static void *slob_alloc_node(struct kmem_cache *c, gfp_t flags, int node,
 
 	if (c->size < PAGE_SIZE) {
 		b = slob_alloc(c->size, flags, c->align, node, 0);
-		trace_kmem_cache_alloc_node(caller, b, c->object_size,
+		trace_kmem_cache_alloc_node(c->name, caller, b, c->object_size,
 					    SLOB_UNITS(c->size) * SLOB_UNIT,
 					    flags, node);
 	} else {
 		b = slob_new_pages(flags, get_order(c->size), node);
-		trace_kmem_cache_alloc_node(caller, b, c->object_size,
+		trace_kmem_cache_alloc_node(c->name, caller, b, c->object_size,
 					    PAGE_SIZE << get_order(c->size),
 					    flags, node);
 	}
@@ -648,7 +648,7 @@  static void kmem_rcu_free(struct rcu_head *head)
 void kmem_cache_free(struct kmem_cache *c, void *b)
 {
 	kmemleak_free_recursive(b, c->flags);
-	trace_kmem_cache_free(_RET_IP_, b, c->name);
+	trace_kmem_cache_free(c->name, _RET_IP_, b);
 	if (unlikely(c->flags & SLAB_TYPESAFE_BY_RCU)) {
 		struct slob_rcu *slob_rcu;
 		slob_rcu = b + (c->size - sizeof(struct slob_rcu));
diff --git a/mm/slub.c b/mm/slub.c
index 1dc9e8eebb62..de03fa1f5667 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3215,7 +3215,7 @@  void *__kmem_cache_alloc_node(struct kmem_cache *s, struct list_lru *lru, gfp_t
 {
 	void *ret = slab_alloc_node(s, lru, gfpflags, node, caller, s->object_size);
 
-	trace_kmem_cache_alloc_node(caller, ret, s->object_size,
+	trace_kmem_cache_alloc_node(s->name, caller, ret, s->object_size,
 				    s->size, gfpflags, node);
 
 	return ret;
@@ -3229,7 +3229,7 @@  void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
 {
 	void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, size);
 
-	trace_kmalloc_node(_RET_IP_, ret,
+	trace_kmalloc_node(s->name, _RET_IP_, ret,
 			   size, s->size, gfpflags, node);
 
 	ret = kasan_kmalloc(s, ret, size, gfpflags);
@@ -3471,7 +3471,7 @@  void kmem_cache_free(struct kmem_cache *s, void *x)
 	s = cache_from_obj(s, x);
 	if (!s)
 		return;
-	trace_kmem_cache_free(_RET_IP_, x, s->name);
+	trace_kmem_cache_free(s->name, _RET_IP_, x);
 	slab_free(s, virt_to_slab(x), x, NULL, 1, _RET_IP_);
 }
 EXPORT_SYMBOL(kmem_cache_free);
@@ -4352,7 +4352,7 @@  void *__kmalloc_node(size_t size, gfp_t flags, int node)
 
 	ret = slab_alloc_node(s, NULL, flags, node, _RET_IP_, size);
 
-	trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node);
+	trace_kmalloc_node(s->name, _RET_IP_, ret, size, s->size, flags, node);
 
 	ret = kasan_kmalloc(s, ret, size, flags);
 
@@ -4811,7 +4811,7 @@  void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
 	ret = slab_alloc_node(s, NULL, gfpflags, node, caller, size);
 
 	/* Honor the call site pointer we received. */
-	trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node);
+	trace_kmalloc_node(s->name, caller, ret, size, s->size, gfpflags, node);
 
 	return ret;
 }