On Tue, 31 Jan 2023 19:57:58 +0100 Andrey Konovalov <andreyknvl@xxxxxxxxx> wrote: > On Tue, Jan 31, 2023 at 9:41 AM Marco Elver <elver@xxxxxxxxxx> wrote: > > > > > diff --git a/lib/stackdepot.c b/lib/stackdepot.c > > > index f291ad6a4e72..cc2fe8563af4 100644 > > > --- a/lib/stackdepot.c > > > +++ b/lib/stackdepot.c > > > @@ -269,8 +269,11 @@ depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc) > > > return NULL; > > > } > > > > > > - /* Move on to the next slab. */ > > > - slab_index++; > > > + /* > > > + * Move on to the next slab. > > > + * WRITE_ONCE annotates a race with stack_depot_fetch. > > > > "Pairs with potential concurrent read in stack_depot_fetch()." would be clearer. > > > > I wouldn't say WRITE_ONCE annotates a race (race = involves 2+ > > accesses, but here's just 1), it just marks this access here which > > itself is paired with the potential racing read in the other function. > > Will do in v2. Thanks! Please let's not redo an 18-patch series for a single line comment change. If there are more substantial changes then OK. I queued this as a to-be-squashed fixup against "/stackdepot: annotate racy slab_index accesses": From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Subject: lib-stackdepot-annotate-racy-slab_index-accesses-fix Date: Tue Jan 31 01:10:50 PM PST 2023 enhance comment, per Marco Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/stackdepot.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/lib/stackdepot.c~lib-stackdepot-annotate-racy-slab_index-accesses-fix +++ a/lib/stackdepot.c @@ -271,7 +271,8 @@ depot_alloc_stack(unsigned long *entries /* * Move on to the next slab. - * WRITE_ONCE annotates a race with stack_depot_fetch. + * WRITE_ONCE pairs with potential concurrent read in + * stack_depot_fetch(). */ WRITE_ONCE(slab_index, slab_index + 1); slab_offset = 0; _
