Re: mmotm 2013-02-19-17-20 uploaded

From: Nathan Zimmer
Date: Thu Feb 21 2013 - 13:18:17 EST


On Thu, Feb 21, 2013 at 01:25:29AM -0800, Stephen Boyd wrote:
> On 2/19/2013 5:21 PM, akpm@xxxxxxxxxxxxxxxxxxxx wrote:
> > * timer_list-split-timer_list_show_tickdevices.patch
> > * timer_list-convert-timer-list-to-be-a-proper-seq_file.patch
> > * timer_list-convert-timer-list-to-be-a-proper-seq_file-fix.patch
> > * timer_list-convert-timer-list-to-be-a-proper-seq_file-v2.patch
> > * timer_list-convert-timer-list-to-be-a-proper-seq_file-v2-fix.patch
> > * timer_list-convert-timer-list-to-be-a-proper-seq_file-fix-fix.patch
>
> These commits seem to break the timer list on devices with maxcpus !=
> nr_cpu_ids, which is possible if you specify maxcpus on the kernel
> command line. I no longer see the percpu devices that I normally have
> after the broadcast device.
Interesting.
However I can't seem to boot at the moment with maxcpus set to less then the actual
number of cpus so I am not having much luck investigating right now.

>
> I also notice what looks like an extra newline inserted in the output
> between the percpu devices and the broadcast device, which may not be
> intentional. There are also some more spelling mistakes in the comments.
> Can we fold in this fix on top of the others (hopefully not white-space
> damaged)?
>
The extra newline was not intentional.

> diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
> index 9904e48..e3cb935 100644
> --- a/kernel/time/timer_list.c
> +++ b/kernel/time/timer_list.c
> @@ -244,7 +244,6 @@ static void timer_list_show_tickdevices_header(struct seq_file *m)
> #endif
> SEQ_printf(m, "\n");
> #endif
> - SEQ_printf(m, "\n");
> }
> #endif
>
> @@ -275,7 +274,7 @@ static int timer_list_show(struct seq_file *m, void *v)
> }
>
> /*
> - * This itererator really needs some explnation since it is offset and has
> + * This iterator really needs some explanation since it is offset and has
> * two passes, one of which is controlled by a config option.
> * In a hotplugged system some cpus, including cpu 0, may be missing so we have
> * to use cpumask_* to iterate over the cpus.
> @@ -283,7 +282,7 @@ static int timer_list_show(struct seq_file *m, void *v)
> * It returns 1 for the header position.
> * For cpu 0 it returns 2 and the final possible cpu would be nr_cpu_ids + 1.
> * On the second pass:
> - * It returnes nr_cpu_ids + 1 for the second header position.
> + * It returns nr_cpu_ids + 1 for the second header position.
> * For cpu 0 it returns nr_cpu_ids + 2
> * The final possible cpu would be nr_cpu_ids + nr_cpu_ids + 2.
> */
> @@ -300,8 +299,12 @@ static void *timer_list_start(struct seq_file *file, loff_t *offset)
> n = cpumask_next(n - 1, cpu_online_mask);
> else
> n = cpumask_first(cpu_online_mask);
> - *offset = n + 1;
> - return (void *)(unsigned long)(n + 2);
> + if (n < nr_cpu_ids) {
> + *offset = n + 1;
> + return (void *)(unsigned long)(n + 2);
> + } else {
> + *offset = n = nr_cpu_ids + 1;
> + }
> }
>
> #ifdef CONFIG_GENERIC_CLOCKEVENTS
> @@ -314,8 +317,10 @@ static void *timer_list_start(struct seq_file *file, loff_t *offset)
> n = cpumask_next(n - 1, cpu_online_mask);
> else
> n = cpumask_first(cpu_online_mask);
> - *offset = n + 2 + nr_cpu_ids;
> - return (void *)(unsigned long)(n + 3 + nr_cpu_ids);
> + if (n < nr_cpu_ids) {
> + *offset = n + 2 + nr_cpu_ids;
> + return (void *)(unsigned long)(n + 3 + nr_cpu_ids);
> + }
> }
> #endif
>
>
> --
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> hosted by The Linux Foundation
>
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