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Groups > linux.kernel > #1572032
| From | Borislav Petkov <bp@alien8.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID |
| Date | 2017-02-01 23:50 +0100 |
| Message-ID | <t6bSW-3Oo-13@gated-at.bofh.it> (permalink) |
| References | <t69o6-26I-21@gated-at.bofh.it> <t6aNc-37z-17@gated-at.bofh.it> <t6aWR-3dV-9@gated-at.bofh.it> <t6b6y-3hm-13@gated-at.bofh.it> <t6bzA-3Hx-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, Feb 01, 2017 at 11:25:07PM +0100, Borislav Petkov wrote:
> On Wed, Feb 01, 2017 at 09:55:44PM +0000, Ghannam, Yazen wrote:
> > Okay, in that case I would prefer to define a synthetic bit. I think it'll be a lot
> > more clear.
>
> No need - it is ok this way too. Now let me apply your changes ontop.
> I'd like to have two separate patches for this.
Ok, here are your changes ontop of the first patch. We can still avoid
the division on SMT-off systems.
More playing with this tomorrow. It is late here and brain wants to
sleep now.
---
From 4b3b9626ef8a535df304aaa017b61436a3b37922 Mon Sep 17 00:00:00 2001
From: Yazen Ghannam <Yazen.Ghannam@amd.com>
Date: Wed, 1 Feb 2017 23:33:16 +0100
Subject: [PATCH] x86/CPU/AMD: Fix Zen SMT topology
After a33d331761bc ("x86/CPU/AMD: Fix Bulldozer topology"), SMT
scheduling topology for Fam17h systems is broken because the ThreadId is
included in the ApicId when SMT is enabled.
So, without further decoding cpu_core_id is unique for each thread
rather than the same for threads on the same core. This didn't affect
systems with SMT disabled. Make cpu_core_id be what it is defined to be.
Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/amd.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index e7158afb322b..349b7d9baf3f 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -319,6 +319,13 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
if (c->x86 == 0x15)
c->cu_id = ebx & 0xff;
+ if (c->x86 >= 0x17) {
+ c->cpu_core_id = ebx & 0xff;
+
+ if (smp_num_siblings > 1)
+ c->x86_max_cores /= smp_num_siblings;
+ }
+
/*
* We may have multiple LLCs if L3 caches exist, so check if we
* have an L3 cache by looking at the L3 cache CPUID leaf.
--
2.11.0
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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[RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID Borislav Petkov <bp@alien8.de> - 2017-02-01 21:10 +0100
RE: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID "Ghannam, Yazen" <Yazen.Ghannam@amd.com> - 2017-02-01 22:40 +0100
Re: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID Borislav Petkov <bp@alien8.de> - 2017-02-01 22:50 +0100
RE: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID "Ghannam, Yazen" <Yazen.Ghannam@amd.com> - 2017-02-01 23:00 +0100
Re: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID Borislav Petkov <bp@alien8.de> - 2017-02-01 23:30 +0100
Re: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID Borislav Petkov <bp@alien8.de> - 2017-02-01 23:50 +0100
Re: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID Borislav Petkov <bp@alien8.de> - 2017-02-02 13:20 +0100
Re: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID Borislav Petkov <bp@alien8.de> - 2017-02-02 16:50 +0100
Re: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID Ingo Molnar <mingo@kernel.org> - 2017-02-02 17:20 +0100
Re: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID Borislav Petkov <bp@alien8.de> - 2017-02-02 18:10 +0100
Re: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID Borislav Petkov <bp@alien8.de> - 2017-02-02 19:20 +0100
RE: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID "Ghannam, Yazen" <Yazen.Ghannam@amd.com> - 2017-02-02 21:50 +0100
RE: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID "Ghannam, Yazen" <Yazen.Ghannam@amd.com> - 2017-02-02 17:20 +0100
Re: [RFC PATCH] x86/CPU/AMD: Bring back Compute Unit ID Ingo Molnar <mingo@kernel.org> - 2017-02-02 17:30 +0100
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