diff mbox series

[GIT,pull] x86/urgent for 6.4-rc4

Message ID 168526036137.3457722.17274974250309862601.tglx@xen13
State New
Headers
Series [GIT,pull] x86/urgent for 6.4-rc4 |

Commit Message

Thomas Gleixner May 28, 2023, 7:53 a.m. UTC 
  Linus,

please pull the latest x86/urgent branch from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-2023-05-28

up to:  edc0a2b59576: x86/topology: Fix erroneous smp_num_siblings on Intel Hybrid platforms


A single fix for x86:

 - Prevent a bogus setting for the number of HT siblings, which is caused
   by the CPUID evaluation trainwreck of X86. That recomputes the value
   for each CPU, so the last CPU "wins". That can cause completely bogus
   sibling values.

Thanks,

	tglx

------------------>
Zhang Rui (1):
      x86/topology: Fix erroneous smp_num_siblings on Intel Hybrid platforms


 arch/x86/kernel/cpu/topology.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

pr-tracker-bot@kernel.org May 28, 2023, 11:46 a.m. UTC | #1 
The pull request you sent on Sun, 28 May 2023 09:53:02 +0200 (CEST):

> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-2023-05-28

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/f8b2507c263d6c1478d179c7c260064a61f14542

Thank you!
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c
index 5e868b62a7c4..0270925fe013 100644
--- a/arch/x86/kernel/cpu/topology.c
+++ b/arch/x86/kernel/cpu/topology.c
@@ -79,7 +79,7 @@  int detect_extended_topology_early(struct cpuinfo_x86 *c)
 	 * initial apic id, which also represents 32-bit extended x2apic id.
 	 */
 	c->initial_apicid = edx;
-	smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
+	smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx));
 #endif
 	return 0;
 }
@@ -109,7 +109,8 @@  int detect_extended_topology(struct cpuinfo_x86 *c)
 	 */
 	cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
 	c->initial_apicid = edx;
-	core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
+	core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
+	smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx));
 	core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
 	die_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
 	pkg_mask_width = die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);