On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin <[email protected]> wrote: > > This commit implements SLUB version of the obj_to_index() function, > which will be required to calculate the offset of obj_cgroup in the > obj_cgroups vector to store/obtain the objcg ownership data. > > To make it faster, let's repeat the SLAB's trick introduced by > commit 6a2d7a955d8d ("[PATCH] SLAB: use a multiply instead of a > divide in obj_to_index()") and avoid an expensive division. > > Vlastimil Babka noticed, that SLUB does have already a similar > function called slab_index(), which is defined only if SLUB_DEBUG > is enabled. The function does a similar math, but with a division, > and it also takes a page address instead of a page pointer. > > Let's remove slab_index() and replace it with the new helper > __obj_to_index(), which takes a page address. obj_to_index() > will be a simple wrapper taking a page pointer and passing > page_address(page) into __obj_to_index(). > > Signed-off-by: Roman Gushchin <[email protected]> > Reviewed-by: Vlastimil Babka <[email protected]> > Acked-by: Johannes Weiner <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
