diff options
| author |   Andy Lutomirski <luto@kernel.org> | 2015-10-05 17:48:18 -0700 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2015-10-09 09:41:11 +0200 |
| commit | 460d12453e1afe20416ce9536cfecb31d17a9abd (patch) | |
| tree | cd6ab9658e1a4afe9641e988803374a129aad727 /arch/x86/entry | |
| parent | x86/entry: Remove unnecessary IRQ twiddling in fast 32-bit syscalls (diff) | |
| download | linux-dev-460d12453e1afe20416ce9536cfecb31d17a9abd.tar.xz linux-dev-460d12453e1afe20416ce9536cfecb31d17a9abd.zip | |
x86/entry: Make irqs_disabled checks in exit code depend on lockdep
These checks are quite slow. Disable them in non-lockdep
kernels to reduce the performance hit.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/eccff2a154ae6fb50f40228901003a6e9c24f3d0.1444091585.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/common.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 0d1c842ef3ca..03aacd188458 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -219,7 +219,7 @@ static struct thread_info *pt_regs_to_thread_info(struct pt_regs *regs) /* Called with IRQs disabled. */ __visible void prepare_exit_to_usermode(struct pt_regs *regs) { - if (WARN_ON(!irqs_disabled())) + if (IS_ENABLED(CONFIG_PROVE_LOCKING) && WARN_ON(!irqs_disabled())) local_irq_disable(); lockdep_sys_exit(); @@ -281,8 +281,8 @@ __visible void syscall_return_slowpath(struct pt_regs *regs) CT_WARN_ON(ct_state() != CONTEXT_KERNEL); - if (WARN(irqs_disabled(), "syscall %ld left IRQs disabled", - regs->orig_ax)) + if (IS_ENABLED(CONFIG_PROVE_LOCKING) && + WARN(irqs_disabled(), "syscall %ld left IRQs disabled", regs->orig_ax)) local_irq_enable(); /* |