On Tue, May 17, 2022 at 08:59:31PM +0900, Hyeonggon Yoo wrote: > On Tue, May 17, 2022 at 12:44:14PM +0300, Vasily Averin wrote: > > dSlab caches marked with SLAB_ACCOUNT force accounting for every > > allocation from this cache even if __GFP_ACCOUNT flag is not passed. > > Unfortunately, at the moment this flag is not visible in ftrace output, > > and this makes it difficult to analyze the accounted allocations. > > > > This patch adds the __GFP_ACCOUNT flag for allocations from slab caches > > marked with SLAB_ACCOUNT to the ftrace output > > --- > > v2: > > 1) handle kmem_cache_alloc_node() too, thanks to Shakeel > > 2) rework kmem_cache_alloc* tracepoints to use cachep instead > > of current cachep->*size parameters. Now kmalloc[_node] and > > kmem_cache_alloc[_node] tracepoints do not use common template > > > > NB: kmem_cache_alloc_node tracepoint in SLOB cannot be switched to cachep, > > therefore it was replaced by kmalloc_node tracepoint. > > --- > > VvS: is this acceptable? Maybe I should split this patch? > > > > Signed-off-by: Vasily Averin <vvs@xxxxxxxxxx> > > --- > > include/trace/events/kmem.h | 82 +++++++++++++++++++++++++++---------- > > mm/slab.c | 7 +--- > > mm/slab_common.c | 7 ++-- > > mm/slob.c | 10 ++--- > > mm/slub.c | 6 +-- > > 5 files changed, 71 insertions(+), 41 deletions(-) > > > > diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h > > index 71c141804222..3b4f96e4a607 100644 > > --- a/include/trace/events/kmem.h > > +++ b/include/trace/events/kmem.h > > @@ -9,7 +9,7 @@ > > #include <linux/tracepoint.h> > > #include <trace/events/mmflags.h> > > > > -DECLARE_EVENT_CLASS(kmem_alloc, > > +TRACE_EVENT(kmalloc, > > > > TP_PROTO(unsigned long call_site, > > const void *ptr, > > @@ -43,23 +43,41 @@ DECLARE_EVENT_CLASS(kmem_alloc, > > show_gfp_flags(__entry->gfp_flags)) > > ); > > > > -DEFINE_EVENT(kmem_alloc, kmalloc, > > +TRACE_EVENT(kmem_cache_alloc, > > > > - TP_PROTO(unsigned long call_site, const void *ptr, > > - size_t bytes_req, size_t bytes_alloc, gfp_t gfp_flags), > > + TP_PROTO(unsigned long call_site, > > + const void *ptr, > > + struct kmem_cache *s, > > + gfp_t gfp_flags), > > > > - TP_ARGS(call_site, ptr, bytes_req, bytes_alloc, gfp_flags) > > -); > > + TP_ARGS(call_site, ptr, s, gfp_flags), > > > > -DEFINE_EVENT(kmem_alloc, kmem_cache_alloc, > > + TP_STRUCT__entry( > > + __field( unsigned long, call_site ) > > + __field( const void *, ptr ) > > + __field( size_t, bytes_req ) > > + __field( size_t, bytes_alloc ) > > + __field( unsigned long, gfp_flags ) > > + ), > > > > - TP_PROTO(unsigned long call_site, const void *ptr, > > - size_t bytes_req, size_t bytes_alloc, gfp_t gfp_flags), > > + TP_fast_assign( > > + __entry->call_site = call_site; > > + __entry->ptr = ptr; > > + __entry->bytes_req = s->object_size; > > + __entry->bytes_alloc = s->size; > > + __entry->gfp_flags = (__force unsigned long)gfp_flags | > > + (s->flags & SLAB_ACCOUNT ? __GFP_ACCOUNT : 0); > > + ), > > This is a bit of lie. SLAB_ACCOUNT is not a gfp flag. > Maybe it is not a problem since the functionalities of SLAB_ACCOUNT and __GFP_ACCOUNT are similar. > IMO the problem here is that we don't know which cache kernel is allocating > from. What about just printing name of cache and remove bytes_req, > bytes_alloc? Is it a problem? Because we have changed the behavior to users. Should we treat the tracepoint as a stable API to users? If so, I think we should not change the parameter of this tracepoint. Maybe I am wrong, just some thoughts from me. Thanks. > > And then you can check if the cache uses SLAB_ACCOUNT or not. >
