From: Borislav Petkov Date: Wed, 6 Jun 2012 15:31:26 +0000 (+0200) Subject: x86/smp: Fix topology checks on AMD MCM CPUs X-Git-Tag: firefly_0821_release~3680^2~2540^2~5 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=161270fc1f9ddfc17154e0d49291472a9cdef7db;p=firefly-linux-kernel-4.4.55.git x86/smp: Fix topology checks on AMD MCM CPUs The warning below triggers on AMD MCM packages because physical package IDs on the cores of a _physical_ socket are the same. I.e., this field says which CPUs belong to the same physical package. However, the same two CPUs belong to two different internal, i.e. "logical" nodes in the same physical socket which is reflected in the CPU-to-node map on x86 with NUMA. Which makes this check wrong on the above topologies so circumvent it. [ 0.444413] Booting Node 0, Processors #1 #2 #3 #4 #5 Ok. [ 0.461388] ------------[ cut here ]------------ [ 0.465997] WARNING: at arch/x86/kernel/smpboot.c:310 topology_sane.clone.1+0x6e/0x81() [ 0.473960] Hardware name: Dinar [ 0.477170] sched: CPU #6's mc-sibling CPU #0 is not on the same node! [node: 1 != 0]. Ignoring dependency. [ 0.486860] Booting Node 1, Processors #6 [ 0.491104] Modules linked in: [ 0.494141] Pid: 0, comm: swapper/6 Not tainted 3.4.0+ #1 [ 0.499510] Call Trace: [ 0.501946] [] ? topology_sane.clone.1+0x6e/0x81 [ 0.508185] [] warn_slowpath_common+0x85/0x9d [ 0.514163] [] warn_slowpath_fmt+0x46/0x48 [ 0.519881] [] topology_sane.clone.1+0x6e/0x81 [ 0.525943] [] set_cpu_sibling_map+0x251/0x371 [ 0.532004] [] start_secondary+0x19a/0x218 [ 0.537729] ---[ end trace 4eaa2a86a8e2da22 ]--- [ 0.628197] #7 #8 #9 #10 #11 Ok. [ 0.807108] Booting Node 3, Processors #12 #13 #14 #15 #16 #17 Ok. [ 0.897587] Booting Node 2, Processors #18 #19 #20 #21 #22 #23 Ok. [ 0.917443] Brought up 24 CPUs We ran a topology sanity check test we have here on it and it all looks ok... hopefully :). Signed-off-by: Borislav Petkov Cc: Andreas Herrmann Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20120529135442.GE29157@aftab.osrc.amd.com Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index fd019d78b1f4..c3a6bacc8a3e 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -349,9 +349,12 @@ static bool __cpuinit match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) static bool __cpuinit match_mc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) { - if (c->phys_proc_id == o->phys_proc_id) - return topology_sane(c, o, "mc"); + if (c->phys_proc_id == o->phys_proc_id) { + if (cpu_has(c, X86_FEATURE_AMD_DCM)) + return true; + return topology_sane(c, o, "mc"); + } return false; }