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Subject[tip:x86/entry] x86/entry: Remove unneeded need_resched() loop
Commit-ID:  b5b447b6b4e899e0978b95cb42d272978f8c7b4d
Gitweb: https://git.kernel.org/tip/b5b447b6b4e899e0978b95cb42d272978f8c7b4d
Author: Valentin Schneider <valentin.schneider@arm.com>
AuthorDate: Mon, 11 Mar 2019 22:47:51 +0000
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 5 Apr 2019 15:08:03 +0200

x86/entry: Remove unneeded need_resched() loop

Since the enabling and disabling of IRQs within preempt_schedule_irq() is
contained in a need_resched() loop, there is no need for the outer
architecture specific loop.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20190311224752.8337-14-valentin.schneider@arm.com

---
arch/x86/entry/entry_32.S | 3 +--
arch/x86/entry/entry_64.S | 3 +--
2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index d309f30cf7af..b1856fe9decf 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -766,13 +766,12 @@ END(ret_from_exception)
#ifdef CONFIG_PREEMPT
ENTRY(resume_kernel)
DISABLE_INTERRUPTS(CLBR_ANY)
-.Lneed_resched:
cmpl $0, PER_CPU_VAR(__preempt_count)
jnz restore_all_kernel
testl $X86_EFLAGS_IF, PT_EFLAGS(%esp) # interrupts off (exception path) ?
jz restore_all_kernel
call preempt_schedule_irq
- jmp .Lneed_resched
+ jmp restore_all_kernel
END(resume_kernel)
#endif

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 1f0efdb7b629..e7e270603fe7 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -645,10 +645,9 @@ retint_kernel:
/* Check if we need preemption */
btl $9, EFLAGS(%rsp) /* were interrupts off? */
jnc 1f
-0: cmpl $0, PER_CPU_VAR(__preempt_count)
+ cmpl $0, PER_CPU_VAR(__preempt_count)
jnz 1f
call preempt_schedule_irq
- jmp 0b
1:
#endif
/*
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