Commit-ID: 8222dbe21e79338de92d5e1956cd1e3994cc9f93 Gitweb: http://git.kernel.org/tip/8222dbe21e79338de92d5e1956cd1e3994cc9f93 Author: David Hildenbrand <[email protected]> AuthorDate: Mon, 11 May 2015 17:52:20 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Tue, 19 May 2015 08:39:18 +0200
sched/preempt, mm/fault: Decouple preemption from the page fault logic As the fault handlers now all rely on the pagefault_disabled() checks and implicit preempt_disable() calls by pagefault_disable() have been made explicit, we can completely rely on the pagefault_disableD counter. So let's no longer touch the preempt count when disabling/enabling pagefaults. After a call to pagefault_disable(), pagefault_disabled() will return true, but in_atomic() won't. Reviewed-and-tested-by: Thomas Gleixner <[email protected]> Signed-off-by: David Hildenbrand <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: [email protected] Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- include/linux/uaccess.h | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 90786d2..ae572c1 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -1,7 +1,6 @@ #ifndef __LINUX_UACCESS_H__ #define __LINUX_UACCESS_H__ -#include <linux/preempt.h> #include <linux/sched.h> #include <asm/uaccess.h> @@ -20,17 +19,11 @@ static __always_inline void pagefault_disabled_dec(void) * These routines enable/disable the pagefault handler. If disabled, it will * not take any locks and go straight to the fixup table. * - * We increase the preempt and the pagefault count, to be able to distinguish - * whether we run in simple atomic context or in a real pagefault_disable() - * context. - * - * For now, after pagefault_disabled() has been called, we run in atomic - * context. User access methods will not sleep. - * + * User access methods will not sleep when called from a pagefault_disabled() + * environment. */ static inline void pagefault_disable(void) { - preempt_count_inc(); pagefault_disabled_inc(); /* * make sure to have issued the store before a pagefault @@ -47,11 +40,6 @@ static inline void pagefault_enable(void) */ barrier(); pagefault_disabled_dec(); -#ifndef CONFIG_PREEMPT - preempt_count_dec(); -#else - preempt_enable(); -#endif } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
