[glibc/release/2.37/master] x86: Fix slight bug in `shared_per_thread` cache size calculation.

[Noah Goldstein <nwg@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=80a8c858a59e963f546a23a745f505ff9b6b1699

commit 80a8c858a59e963f546a23a745f505ff9b6b1699
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date:   Mon Jul 17 23:14:33 2023 -0500

    x86: Fix slight bug in `shared_per_thread` cache size calculation.
    
    After:
    ```
        commit af992e7abdc9049714da76cae1e5e18bc4838fb8
        Author: Noah Goldstein <goldstein.w.n@gmail.com>
        Date:   Wed Jun 7 13:18:01 2023 -0500
    
            x86: Increase `non_temporal_threshold` to roughly `sizeof_L3 / 4`
    ```
    
    Split `shared` (cumulative cache size) from `shared_per_thread` (cache
    size per socket), the `shared_per_thread` *can* be slightly off from
    the previous calculation.
    
    Previously we added `core` even if `threads_l2` was invalid, and only
    used `threads_l2` to divide `core` if it was present. The changed
    version only included `core` if `threads_l2` was valid.
    
    This change restores the old behavior if `threads_l2` is invalid by
    adding the entire value of `core`.
    Reviewed-by: DJ Delorie <dj@redhat.com>
    
    (cherry picked from commit 47f747217811db35854ea06741be3685e8bbd44d)

Diff:
---
 sysdeps/x86/dl-cacheinfo.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sysdeps/x86/dl-cacheinfo.h b/sysdeps/x86/dl-cacheinfo.h
index d7a501ad9a..f5b04f489e 100644
--- a/sysdeps/x86/dl-cacheinfo.h
+++ b/sysdeps/x86/dl-cacheinfo.h
@@ -615,8 +615,8 @@ get_common_cache_info (long int *shared_ptr, long int * shared_per_thread_ptr, u
   /* Account for non-inclusive L2 and L3 caches.  */
   if (!inclusive_cache)
     {
-      if (threads_l2 > 0)
-	shared_per_thread += core / threads_l2;
+      long int core_per_thread = threads_l2 > 0 ? (core / threads_l2) : core;
+      shared_per_thread += core_per_thread;
       shared += core;
     }