On Mon, 3 Feb 2025 09:34:29 +0100 Vlastimil Babka <[email protected]> wrote:
> On 1/30/25 19:16, Wander Lairson Costa wrote: > > The kmem_cache_free tracepoint includes a "name" field, which allows > > for easy identification and filtering of specific kmem's. However, the > > kmem_cache_alloc tracepoint lacks this field, making it difficult to > > pair corresponding alloc and free events for analysis. > > Hm yeah looks like the free one was added in commit 3544de8ee6e48 and their > use case didn't need alloc too, but it makes sense. > > > Add the "name" field to kmem_cache_alloc to enable consistent tracking > > and correlation of kmem alloc and free events. > > > > Signed-off-by: Wander Lairson Costa <[email protected]> > > I will take this in the slab tree, unless Steven objects. No objections but... > > Thanks, > Vlastimil > > > --- > > include/trace/events/kmem.h | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h > > index b37eb0a7060f..8ffb022f024c 100644 > > --- a/include/trace/events/kmem.h > > +++ b/include/trace/events/kmem.h > > @@ -22,6 +22,7 @@ TRACE_EVENT(kmem_cache_alloc, > > TP_STRUCT__entry( > > __field( unsigned long, call_site ) > > __field( const void *, ptr ) > > + __string( name, s->name ) The string place holder in the "struct" is 4 bytes and not a pointer. So I would place it either at the end or next to another "int" to avoid any holes caused by it being placed next to a 8 byte field. -- Steve > > __field( size_t, bytes_req ) > > __field( size_t, bytes_alloc ) > > __field( unsigned long, gfp_flags ) > > @@ -32,6 +33,7 @@ TRACE_EVENT(kmem_cache_alloc, > > TP_fast_assign( > > __entry->call_site = call_site; > > __entry->ptr = ptr; > > + __assign_str(name); > > __entry->bytes_req = s->object_size; > > __entry->bytes_alloc = s->size; > > __entry->gfp_flags = (__force unsigned long)gfp_flags; > > @@ -41,9 +43,10 @@ TRACE_EVENT(kmem_cache_alloc, > > (s->flags & SLAB_ACCOUNT)) : false; > > ), > > > > - TP_printk("call_site=%pS ptr=%p bytes_req=%zu bytes_alloc=%zu > > gfp_flags=%s node=%d accounted=%s", > > + TP_printk("call_site=%pS ptr=%p name=%s bytes_req=%zu bytes_alloc=%zu > > gfp_flags=%s node=%d accounted=%s", > > (void *)__entry->call_site, > > __entry->ptr, > > + __get_str(name), > > __entry->bytes_req, > > __entry->bytes_alloc, > > show_gfp_flags(__entry->gfp_flags),
