Srivatsa S. Bhat
2013-Jun-25 20:30 UTC
[PATCH v2 30/45] x86/xen: Use get/put_online_cpus_atomic() to prevent CPU offline
Once stop_machine() is gone from the CPU offline path, we won't be able to depend on disabling preemption to prevent CPUs from going offline from under us. Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going offline, while invoking from atomic context. Cc: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com> Cc: Jeremy Fitzhardinge <jeremy at goop.org> Cc: Thomas Gleixner <tglx at linutronix.de> Cc: Ingo Molnar <mingo at redhat.com> Cc: "H. Peter Anvin" <hpa at zytor.com> Cc: x86 at kernel.org Cc: xen-devel at lists.xensource.com Cc: virtualization at lists.linux-foundation.org Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat at linux.vnet.ibm.com> --- arch/x86/xen/mmu.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index fdc3ba2..3229c4f 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -39,6 +39,7 @@ * Jeremy Fitzhardinge <jeremy at xensource.com>, XenSource Inc, 2007 */ #include <linux/sched.h> +#include <linux/cpu.h> #include <linux/highmem.h> #include <linux/debugfs.h> #include <linux/bug.h> @@ -1163,9 +1164,13 @@ static void xen_drop_mm_ref(struct mm_struct *mm) */ static void xen_exit_mmap(struct mm_struct *mm) { - get_cpu(); /* make sure we don't move around */ + /* + * Make sure we don't move around, and also prevent CPUs from + * going offline. + */ + get_online_cpus_atomic(); xen_drop_mm_ref(mm); - put_cpu(); + put_online_cpus_atomic(); spin_lock(&mm->page_table_lock);
Apparently Analagous Threads
- [PATCH 30/45] x86/xen: Use get/put_online_cpus_atomic() to prevent CPU offline
- [PATCH 30/45] x86/xen: Use get/put_online_cpus_atomic() to prevent CPU offline
- [PATCH v2 30/45] x86/xen: Use get/put_online_cpus_atomic() to prevent CPU offline
- [PATCH v2 30/45] x86/xen: Use get/put_online_cpus_atomic() to prevent CPU offline
- [PATCH v3 30/45] x86/xen: Use get/put_online_cpus_atomic() to prevent CPU offline