Messages in this thread Patch in this message | | | From | KOSAKI Motohiro <> | Subject | [PATCH v2] x86-64, NUMA: fix fakenuma boot failure | Date | Thu, 14 Apr 2011 09:51:00 +0900 (JST) |
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Hi
> Hello, > > On Wed, Apr 13, 2011 at 04:02:43PM +0900, KOSAKI Motohiro wrote: > > Your patch have two mistake. > > > > 1) link_thread_siblings() is for HT > > set_cpu_sibling_map() has another sibling calculations. > > 2) numa_set_node() is not enough. scheduler is using node_to_cpumask_map[] too. > > Thanks for seeing this through but your patch is badly whitespace > broken. Can you please check your mail setup and repost? Also, some > comments below.
hmm... My carbon copy is not corrupted. Maybe crappy intermediate server override it?
> > btw, Please see cpu_coregroup_mask(). its return value depend on > > sched_mc_power_savings and sched_smt_power_savings. then, we need to care > > both cpu_core_mask and cpu_llc_shared_mask. I think. > > Hmmmm.... > > > +static void __cpuinit node_cpumap_same_phys(int cpu1, int cpu2) > > What does the "phys" mean? Maybe something like > check_cpu_siblings_on_same_node() is a better name?
ok, will fix.
> > > + /* > > + * Our CPU scheduler assume all cpus in the same physical cpu package > > + * are assigned the same node. But, Buggy ACPI table or NUMA emulation > > + * might assigne them to different node. Fix it. > typo
Grr. thank you.
> > > + */ > > + if (node1 != node2) { > > + pr_warning("CPU %d in node %d and CPU %d in node %d are in the same physical CPU. forcing same node %d\n", > > + cpu1, node1, cpu2, node2, node2); > > + > > + numa_set_node(cpu1, node2); > > + cpumask_set_cpu(cpu1, node_to_cpumask_map[node2]); > > + cpumask_clear_cpu(cpu1, node_to_cpumask_map[node1]); > > Maybe what you want is the following? > > numa_remove_cpu(cpu1); > numa_set_node(cpu1, node2) > numa_add_cpu(cpu1)
Right. That's better.
From 1b7868de51941f39699c08f0d6ab429cd9db15bf Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Date: Wed, 13 Apr 2011 15:47:12 +0900 Subject: [PATCH] x86-64, NUMA: fix fakenuma boot failure
Currently, numa=fake boot parameter is broken. If it's used, kernel doesn't boot and makes panic by zero divide error.
Call Trace: [<ffffffff8104ad4c>] find_busiest_group+0x38c/0xd30 [<ffffffff81086aff>] ? local_clock+0x6f/0x80 [<ffffffff81050533>] load_balance+0xa3/0x600 [<ffffffff81050f53>] idle_balance+0xf3/0x180 [<ffffffff81550092>] schedule+0x722/0x7d0 [<ffffffff81550538>] ? wait_for_common+0x128/0x190 [<ffffffff81550a65>] schedule_timeout+0x265/0x320 [<ffffffff81095815>] ? lock_release_holdtime+0x35/0x1a0 [<ffffffff81550538>] ? wait_for_common+0x128/0x190 [<ffffffff8109bb6c>] ? __lock_release+0x9c/0x1d0 [<ffffffff815534e0>] ? _raw_spin_unlock_irq+0x30/0x40 [<ffffffff815534e0>] ? _raw_spin_unlock_irq+0x30/0x40 [<ffffffff81550540>] wait_for_common+0x130/0x190 [<ffffffff81051920>] ? try_to_wake_up+0x510/0x510 [<ffffffff8155067d>] wait_for_completion+0x1d/0x20 [<ffffffff8107f36c>] kthread_create_on_node+0xac/0x150 [<ffffffff81077bb0>] ? process_scheduled_works+0x40/0x40 [<ffffffff8155045f>] ? wait_for_common+0x4f/0x190 [<ffffffff8107a283>] __alloc_workqueue_key+0x1a3/0x590 [<ffffffff81e0cce2>] cpuset_init_smp+0x6b/0x7b [<ffffffff81df3d07>] kernel_init+0xc3/0x182 [<ffffffff8155d5e4>] kernel_thread_helper+0x4/0x10 [<ffffffff81553cd4>] ? retint_restore_args+0x13/0x13 [<ffffffff81df3c44>] ? start_kernel+0x400/0x400 [<ffffffff8155d5e0>] ? gs_change+0x13/0x13
The zero divede is caused following line. (ie group->cpu_power==0)
update_sg_lb_stats() /* Adjust by relative CPU power of the group */ sgs->avg_load = (sgs->group_load * SCHED_LOAD_SCALE) / group->cpu_power;
This is regression since commit e23bba6044 (x86-64, NUMA: Unify emulated distance mapping). Because It drop fake_physnodes() and then cpu-node mapping was changed.
old) all cpus are assinged node 0 now) cpus are assigned round robin (the logic is implemented by numa_init_array())
Why round robin assignment doesn't work? Because init_numa_sched_groups_power() assume all logical cpus in the same physical cpu are assigned the same node. (Then it only account group_first_cpu()). But the simple round robin broke the above assumption.
Thus, this patch implement to reassigne node-id if buggy firmware or numa emulation makes wrong cpu node map.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Shaohui Zheng <shaohui.zheng@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: H. Peter Anvin <hpa@linux.intel.com> --- arch/x86/kernel/smpboot.c | 23 +++++++++++++++++++++++ 1 files changed, 23 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index c2871d3..78c422d 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -312,6 +312,26 @@ void __cpuinit smp_store_cpu_info(int id) identify_secondary_cpu(c); } +static void __cpuinit check_cpu_siblings_on_same_node(int cpu1, int cpu2) +{ + int node1 = early_cpu_to_node(cpu1); + int node2 = early_cpu_to_node(cpu2); + + /* + * Our CPU scheduler assume all logical cpus in the same physical cpu + * package are assigned the same node. But, Buggy ACPI table or NUMA + * emulation might assign them to different node. Fix it. + */ + if (node1 != node2) { + pr_warning("CPU %d in node %d and CPU %d in node %d are in the same physical CPU. forcing same node %d\n", + cpu1, node1, cpu2, node2, node2); + + numa_remove_cpu(cpu1); + numa_set_node(cpu1, node2); + numa_add_cpu(cpu1); + } +} + static void __cpuinit link_thread_siblings(int cpu1, int cpu2) { cpumask_set_cpu(cpu1, cpu_sibling_mask(cpu2)); @@ -320,6 +340,7 @@ static void __cpuinit link_thread_siblings(int cpu1, int cpu2) cpumask_set_cpu(cpu2, cpu_core_mask(cpu1)); cpumask_set_cpu(cpu1, cpu_llc_shared_mask(cpu2)); cpumask_set_cpu(cpu2, cpu_llc_shared_mask(cpu1)); + check_cpu_siblings_on_same_node(cpu1, cpu2); } @@ -361,10 +382,12 @@ void __cpuinit set_cpu_sibling_map(int cpu) per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) { cpumask_set_cpu(i, cpu_llc_shared_mask(cpu)); cpumask_set_cpu(cpu, cpu_llc_shared_mask(i)); + check_cpu_siblings_on_same_node(cpu, i); } if (c->phys_proc_id == cpu_data(i).phys_proc_id) { cpumask_set_cpu(i, cpu_core_mask(cpu)); cpumask_set_cpu(cpu, cpu_core_mask(i)); + check_cpu_siblings_on_same_node(cpu, i); /* * Does this new cpu bringup a new core? */ -- 1.7.3.1
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