| Message ID | 1399068558-2373-2-git-send-email-john.stultz@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Fri 02-05-14 15:09:15, John Stultz wrote: > A commit in akpm's tree (printk: remove separate printk_sched > buffers...), removed the printk_sched irqsave/restore lines > since it was safe for current users. Since we may be expanding > usage of printk_sched(), re-add the irqsave/restore logic > to make the functionality more generally safe. So I'm just wondering: Do you have anything particular for which you need interrupts disabled? Won't e.g. disabling preemption be enough? Honza > Cc: Jan Kara <jack@suse.cz> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Jiri Bohac <jbohac@suse.cz> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Steven Rostedt <rostedt@goodmis.org> > Signed-off-by: John Stultz <john.stultz@linaro.org> > --- > kernel/printk/printk.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > index 82d19e6..bf62f2b 100644 > --- a/kernel/printk/printk.c > +++ b/kernel/printk/printk.c > @@ -2586,15 +2586,18 @@ void wake_up_klogd(void) > > int printk_sched(const char *fmt, ...) > { > + unsigned long flags; > va_list args; > int r; > > + local_irq_save(flags); > va_start(args, fmt); > r = vprintk_emit(0, SCHED_MESSAGE_LOGLEVEL, NULL, 0, fmt, args); > va_end(args); > > __this_cpu_or(printk_pending, PRINTK_PENDING_OUTPUT); > irq_work_queue(&__get_cpu_var(wake_up_klogd_work)); > + local_irq_restore(flags); > > return r; > } > -- > 1.9.1 >
On Sun, May 04, 2014 at 04:58:47PM +0200, Jan Kara wrote: > On Fri 02-05-14 15:09:15, John Stultz wrote: > > A commit in akpm's tree (printk: remove separate printk_sched > > buffers...), removed the printk_sched irqsave/restore lines > > since it was safe for current users. Since we may be expanding > > usage of printk_sched(), re-add the irqsave/restore logic > > to make the functionality more generally safe. > So I'm just wondering: Do you have anything particular for which you need > interrupts disabled? Won't e.g. disabling preemption be enough? Yeah, I think preemption disabled is sufficient. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 05/04/2014 09:13 AM, Peter Zijlstra wrote: > On Sun, May 04, 2014 at 04:58:47PM +0200, Jan Kara wrote: >> On Fri 02-05-14 15:09:15, John Stultz wrote: >>> A commit in akpm's tree (printk: remove separate printk_sched >>> buffers...), removed the printk_sched irqsave/restore lines >>> since it was safe for current users. Since we may be expanding >>> usage of printk_sched(), re-add the irqsave/restore logic >>> to make the functionality more generally safe. >> So I'm just wondering: Do you have anything particular for which you need >> interrupts disabled? Won't e.g. disabling preemption be enough? > Yeah, I think preemption disabled is sufficient. Ok, will change this and resend. thanks -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 82d19e6..bf62f2b 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2586,15 +2586,18 @@ void wake_up_klogd(void) int printk_sched(const char *fmt, ...) { + unsigned long flags; va_list args; int r; + local_irq_save(flags); va_start(args, fmt); r = vprintk_emit(0, SCHED_MESSAGE_LOGLEVEL, NULL, 0, fmt, args); va_end(args); __this_cpu_or(printk_pending, PRINTK_PENDING_OUTPUT); irq_work_queue(&__get_cpu_var(wake_up_klogd_work)); + local_irq_restore(flags); return r; }
A commit in akpm's tree (printk: remove separate printk_sched buffers...), removed the printk_sched irqsave/restore lines since it was safe for current users. Since we may be expanding usage of printk_sched(), re-add the irqsave/restore logic to make the functionality more generally safe. Cc: Jan Kara <jack@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Bohac <jbohac@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: John Stultz <john.stultz@linaro.org> --- kernel/printk/printk.c | 3 +++ 1 file changed, 3 insertions(+)