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| author | Peter Zijlstra | 2018-05-22 18:50:53 +0200 |
|---|---|---|
| committer | Paul E. McKenney | 2018-05-23 01:12:26 +0200 |
| commit | f64c6013a2029316ea552f99823d116ee5f5f955 (patch) | |
| tree | 07426bae4e4500acc8bc64a0edd0c6fe6b298e6e /arch/x86/kernel/cpu/mtrr/main.c | |
| parent | Merge branches 'exp.2018.05.15a', 'fixes.2018.05.15a', 'lock.2018.05.15a' and... (diff) | |
| download | kernel-qcow2-linux-f64c6013a2029316ea552f99823d116ee5f5f955.tar.gz kernel-qcow2-linux-f64c6013a2029316ea552f99823d116ee5f5f955.tar.xz kernel-qcow2-linux-f64c6013a2029316ea552f99823d116ee5f5f955.zip | |
rcu/x86: Provide early rcu_cpu_starting() callback
The x86/mtrr code does horrific things because hardware. It uses
stop_machine_from_inactive_cpu(), which does a wakeup (of the stopper
thread on another CPU), which uses RCU, all before the CPU is onlined.
RCU complains about this, because wakeups use RCU and RCU does
(rightfully) not consider offline CPUs for grace-periods.
Fix this by initializing RCU way early in the MTRR case.
Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Add !SMP support, per 0day Test Robot report. ]
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/main.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/main.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c index 7468de429087..3ea0047beb40 100644 --- a/arch/x86/kernel/cpu/mtrr/main.c +++ b/arch/x86/kernel/cpu/mtrr/main.c @@ -46,6 +46,7 @@ #include <linux/pci.h> #include <linux/smp.h> #include <linux/syscore_ops.h> +#include <linux/rcupdate.h> #include <asm/cpufeature.h> #include <asm/e820/api.h> @@ -793,6 +794,9 @@ void mtrr_ap_init(void) if (!use_intel() || mtrr_aps_delayed_init) return; + + rcu_cpu_starting(smp_processor_id()); + /* * Ideally we should hold mtrr_mutex here to avoid mtrr entries * changed, but this routine will be called in cpu boot time, |