[glibc/release/2.31/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=047968e81d03836253beef81f376abe0a82e6857

commit 047968e81d03836253beef81f376abe0a82e6857
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date:   Fri Aug 11 18:48:18 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/cacheinfo.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sysdeps/x86/cacheinfo.c b/sysdeps/x86/cacheinfo.c
index a30d0bcfc6..67173970e1 100644
--- a/sysdeps/x86/cacheinfo.c
+++ b/sysdeps/x86/cacheinfo.c
@@ -696,8 +696,8 @@ init_cacheinfo (void)
       /* 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;
 	}
     }