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authorFenghua Yu <fenghua.yu@intel.com>2016-12-01 12:55:14 -0800
committerThomas Gleixner <tglx@linutronix.de>2016-12-02 01:13:02 +0100
commit74fcdae1a7fdf30de5413ccc1eca271415d01124 (patch)
treea742dd6c925c16c6fda8d3c34393b4ec19db8db7 /arch/x86/include/asm
parent0efc89be9471b152599d2db7eb47de8e0d71c59f (diff)
x86/intel_rdt: Call intel_rdt_sched_in() with preemption disabled
intel_rdt_sched_in() must be called with preemption disabled because the function accesses percpu variables (pqr_state and closid). If a task moves itself via move_myself() preemption is enabled, which violates the calling convention and can result in incorrect closid selection when the task gets preempted or migrated. Add the required protection and a comment about the calling convention. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com> Cc: "Tony Luck" <tony.luck@intel.com> Cc: "Marcelo Tosatti" <mtosatti@redhat.com> Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com> Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com> Cc: "H. Peter Anvin" <h.peter.anvin@intel.com> Link: http://lkml.kernel.org/r/1480625714-54246-1-git-send-email-fenghua.yu@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/include/asm')
-rw-r--r--arch/x86/include/asm/intel_rdt.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/intel_rdt.h b/arch/x86/include/asm/intel_rdt.h
index 6e90e87eadfe..95ce5c85b009 100644
--- a/arch/x86/include/asm/intel_rdt.h
+++ b/arch/x86/include/asm/intel_rdt.h
@@ -192,6 +192,8 @@ int rdtgroup_schemata_show(struct kernfs_open_file *of,
* resctrl file system.
* - Caches the per cpu CLOSid values and does the MSR write only
* when a task with a different CLOSid is scheduled in.
+ *
+ * Must be called with preemption disabled.
*/
static inline void intel_rdt_sched_in(void)
{