On Wed, Mar 15, 2023 at 02:38:47PM +0100, Vlastimil Babka wrote: > On 3/12/23 10:59, Mike Rapoport wrote: > > On Fri, Mar 10, 2023 at 11:32:09AM +0100, Vlastimil Babka wrote: > >> This will make it easier to free objects in situations when they can > >> come from either kmalloc() or kmem_cache_alloc(), and also allow > >> kfree_rcu() for freeing objects from kmem_cache_alloc(). > >> > >> For the SLAB and SLUB allocators this was always possible so with SLOB > >> gone, we can document it as supported. > >> > >> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> > >> Cc: Mike Rapoport <rppt@xxxxxxxxxx> > >> Cc: Jonathan Corbet <corbet@xxxxxxx> > >> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx> > >> Cc: Frederic Weisbecker <frederic@xxxxxxxxxx> > >> Cc: Neeraj Upadhyay <quic_neeraju@xxxxxxxxxxx> > >> Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx> > >> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> > >> Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> > >> Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx> > >> Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> > >> --- > >> Documentation/core-api/memory-allocation.rst | 15 +++++++++++---- > >> include/linux/rcupdate.h | 6 ++++-- > >> mm/slab_common.c | 5 +---- > >> 3 files changed, 16 insertions(+), 10 deletions(-) > >> > >> diff --git a/Documentation/core-api/memory-allocation.rst b/Documentation/core-api/memory-allocation.rst > >> index 5954ddf6ee13..f9e8d352ed67 100644 > >> --- a/Documentation/core-api/memory-allocation.rst > >> +++ b/Documentation/core-api/memory-allocation.rst > >> @@ -170,7 +170,14 @@ should be used if a part of the cache might be copied to the userspace. > >> After the cache is created kmem_cache_alloc() and its convenience > >> wrappers can allocate memory from that cache. > >> > >> -When the allocated memory is no longer needed it must be freed. You can > >> -use kvfree() for the memory allocated with `kmalloc`, `vmalloc` and > >> -`kvmalloc`. The slab caches should be freed with kmem_cache_free(). And > >> -don't forget to destroy the cache with kmem_cache_destroy(). > >> +When the allocated memory is no longer needed it must be freed. Objects > > > > I'd add a line break before Objects ^ > > > >> +allocated by `kmalloc` can be freed by `kfree` or `kvfree`. > >> +Objects allocated by `kmem_cache_alloc` can be freed with `kmem_cache_free` > >> +or also by `kfree` or `kvfree`, which can be more convenient as it does > > > > Maybe replace 'or also by' with a coma: > > > > Objects allocated by `kmem_cache_alloc` can be freed with `kmem_cache_free`, > > `kfree` or `kvfree`, which can be more convenient as it does > > But then I need to clarify what the "which" applies to? Yeah, I kinda missed that... > > > >> +not require the kmem_cache pointed. > > > > ^ pointer. > > > >> +The rules for _bulk and _rcu flavors of freeing functions are analogical. > > > > Maybe > > > > The same rules apply to _bulk and _rcu flavors of freeing functions. > > So like this incremental diff? > diff --git a/Documentation/core-api/memory-allocation.rst b/Documentation/core-api/memory-allocation.rst > index f9e8d352ed67..1c58d883b273 100644 > --- a/Documentation/core-api/memory-allocation.rst > +++ b/Documentation/core-api/memory-allocation.rst > @@ -170,12 +170,14 @@ should be used if a part of the cache might be copied to the userspace. > After the cache is created kmem_cache_alloc() and its convenience > wrappers can allocate memory from that cache. > > -When the allocated memory is no longer needed it must be freed. Objects > -allocated by `kmalloc` can be freed by `kfree` or `kvfree`. > -Objects allocated by `kmem_cache_alloc` can be freed with `kmem_cache_free` > -or also by `kfree` or `kvfree`, which can be more convenient as it does > -not require the kmem_cache pointed. > -The rules for _bulk and _rcu flavors of freeing functions are analogical. > +When the allocated memory is no longer needed it must be freed. > + > +Objects allocated by `kmalloc` can be freed by `kfree` or `kvfree`. Objects > +allocated by `kmem_cache_alloc` can be freed with `kmem_cache_free`, `kfree` > +or `kvfree`, where the latter two might be more convenient thanks to not > +needing the kmem_cache pointer. ... but this way it's more explicit that kfree and kvfree don't need kmem_cache pointer. > + > +The same rules apply to _bulk and _rcu flavors of freeing functions. > > Memory allocated by `vmalloc` can be freed with `vfree` or `kvfree`. > Memory allocated by `kvmalloc` can be freed with `kvfree`. > -- Sincerely yours, Mike.
