diff options
| author | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-12-12 10:37:03 -0500 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-12-12 10:54:48 -0500 |
| commit | 3e12758392bee50135301b0189c064ab80980aca (patch) | |
| tree | 6b7396edb304412a33c7dd7babde585145b79bb9 /arch/x86/mm | |
| parent | c1ac03af6ed45d05786c219d102f37eb44880f28 (diff) | |
| download | lwn-3e12758392bee50135301b0189c064ab80980aca.tar.gz lwn-3e12758392bee50135301b0189c064ab80980aca.zip | |
x86/mm/kmmio: Remove redundant preempt_disable()
Now that kmmio uses rcu_read_lock_sched_notrace() there's no reason to
call preempt_disable() as the read_lock_sched_notrace() already does that
and is redundant.
This also removes the preempt_enable_no_resched() as the "no_resched()"
portion was bogus as there's no reason to do that.
Link: https://lkml.kernel.org/r/20221212103703.7129cc5d@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "x86@kernel.org" <x86@kernel.org>
Cc: Karol Herbst <karolherbst@gmail.com>
Cc: Pekka Paalanen <ppaalanen@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/kmmio.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c index 853c49877c16..9f82019179e1 100644 --- a/arch/x86/mm/kmmio.c +++ b/arch/x86/mm/kmmio.c @@ -246,14 +246,13 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) page_base &= page_level_mask(l); /* - * Preemption is now disabled to prevent process switch during - * single stepping. We can only handle one active kmmio trace + * Hold the RCU read lock over single stepping to avoid looking + * up the probe and kmmio_fault_page again. The rcu_read_lock_sched() + * also disables preemption and prevents process switch during + * the single stepping. We can only handle one active kmmio trace * per cpu, so ensure that we finish it before something else - * gets to run. We also hold the RCU read lock over single - * stepping to avoid looking up the probe and kmmio_fault_page - * again. + * gets to run. */ - preempt_disable(); rcu_read_lock_sched_notrace(); faultpage = get_kmmio_fault_page(page_base); @@ -324,7 +323,6 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) no_kmmio: rcu_read_unlock_sched_notrace(); - preempt_enable_no_resched(); return ret; } @@ -364,7 +362,6 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) ctx->active--; BUG_ON(ctx->active); rcu_read_unlock_sched_notrace(); - preempt_enable_no_resched(); /* * if somebody else is singlestepping across a probe point, flags |