On Fri, Aug 04, 2023 at 06:24:18PM -0700, Ricardo Neri wrote: > Hi, Hi Ricardo, > This is v3 of a patchset to set the number of cache leaves independently > for each CPU. v1 and v2 can be found here [1] and here [2]. I am on CC of your patch set and glanced through it. Long ago I've touched related code but now I am not really up-to-date to do a qualified review in this area. First, I would have to look into documentation to refresh my memory etc. pp. I've not seen (or it escaped me) information that this was tested on a variety of machines that might be affected by this change. And there are no Tested-by-tags. Even if changes look simple and reasonable they can cause issues. Thus from my POV it would be good to have some information what tests were done. I am not asking to test on all possible systems but just knowing which system(s) was (were) used for functional testing is of value. > Changes since v2: > * This version uncovered a NULL-pointer dereference in recent changes to > cacheinfo[3]. This dereference is observed when the system does not > configure cacheinfo early during boot nor makes corrections later > during CPU hotplug; as is the case in x86. Patch 1 fixes this issue. > > Changes since v1: > * Dave Hansen suggested to use the existing per-CPU ci_cpu_cacheinfo > variable. Now the global variable num_cache_leaves became useless. > * While here, I noticed that init_cache_level() also became useless: > x86 does not need ci_cpu_cacheinfo::num_levels. > > [1]. https://lore.kernel.org/lkml/20230314231658.30169-1-ricardo.neri-calderon@xxxxxxxxxxxxxxx/ > [2]. https://lore.kernel.org/all/20230424001956.21434-1-ricardo.neri-calderon@xxxxxxxxxxxxxxx/ > [3]. https://lore.kernel.org/all/20230412185759.755408-1-rrendec@xxxxxxxxxx/ > > Ricardo Neri (3): > cacheinfo: Allocate memory for memory if not done from the primary CPU > x86/cacheinfo: Delete global num_cache_leaves > x86/cacheinfo: Clean out init_cache_level() > > arch/x86/kernel/cpu/cacheinfo.c | 50 ++++++++++++++++----------------- > drivers/base/cacheinfo.c | 6 +++- > 2 files changed, 30 insertions(+), 26 deletions(-) > > -- > 2.25.1 > -- Regards, Andreas SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nürnberg, Germany GF: Ivo Totev, Andrew McDonald, Werner Knoblich (HRB 36809, AG Nürnberg)
