284f17ac13
Currently we have a single function slab_free() handling both single object freeing and bulk freeing with necessary hooks, the latter case requiring slab_free_freelist_hook(). It should be however better to distinguish the two use cases for the following reasons: - code simpler to follow for the single object case - better code generation - although inlining should eliminate the slab_free_freelist_hook() for single object freeing in case no debugging options are enabled, it seems it's not perfect. When e.g. KASAN is enabled, we're imposing additional unnecessary overhead for single object freeing. - preparation to add percpu array caches in near future Therefore, simplify slab_free() for the single object case by dropping unnecessary parameters and calling only slab_free_hook() instead of slab_free_freelist_hook(). Rename the bulk variant to slab_free_bulk() and adjust callers accordingly. While at it, flip (and document) slab_free_hook() return value so that it returns true when the freeing can proceed, which matches the logic of slab_free_freelist_hook() and is not confusingly the opposite. Additionally we can simplify a bit by changing the tail parameter of do_slab_free() when freeing a single object - instead of NULL we can set it equal to head. bloat-o-meter shows small code reduction with a .config that has KASAN etc disabled: add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-118 (-118) Function old new delta kmem_cache_alloc_bulk 1203 1196 -7 kmem_cache_free 861 835 -26 __kmem_cache_free 741 704 -37 kmem_cache_free_bulk 911 863 -48 Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.