On Fri, Mar 13, 2015 at 06:10:51PM +0800, Xie XiuQi wrote:
> Memory-failure as the high level machine check handler, it's necessary
> to report memory page recovery action result to user space by ftrace.
>
> This patch add a event at ras group for memory-failure.
>
> The output like below:
> # tracer: nop
> #
> # entries-in-buffer/entries-written: 2/2 #P:24
> #
> # _-----=> irqs-off
> # / _----=> need-resched
> # | / _---=> hardirq/softirq
> # || / _--=> preempt-depth
> # ||| / delay
> # TASK-PID CPU# |||| TIMESTAMP FUNCTION
> # | | | |||| | |
> mce-inject-13150 [001] .... 277.019359: memory_failure_event: pfn 0x19869: free buddy page recovery: Delayed
>
> Signed-off-by: Xie XiuQi <xiexiuqi@xxxxxxxxxx>
> ---
> include/ras/ras_event.h | 36 ++++++++++++++++++++++++++++++++++++
> mm/memory-failure.c | 3 +++
> 2 files changed, 39 insertions(+), 0 deletions(-)
>
> diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h
> index 79abb9c..0a6c8f3 100644
> --- a/include/ras/ras_event.h
> +++ b/include/ras/ras_event.h
> @@ -232,6 +232,42 @@ TRACE_EVENT(aer_event,
> __print_flags(__entry->status, "|", aer_uncorrectable_errors))
> );
>
> +/*
> + * memory-failure recovery action result event
> + *
> + * unsigned long pfn - Page Number of the corrupted page
> + * char * action - Recovery action: "free buddy", "free huge", "high
> + * order kernel", "free buddy, 2nd try", "different
> + * compound page after locking", "hugepage already
> + * hardware poisoned", "unmapping failed", "already
> + * truncated LRU", etc.
Listing all possible values here might be prone to become out of date when
someone try to add/remove/change action_result() call sites.
So I'd like to have some enumerator to bundle these strings in one place
in mm/memory-failure.c.
# I feel like doing this later.
> + * char * result - Action result: Ignored, Failed, Delayed, Recovered.
mm/memory-failure.c has good explanation:
/*
* Error handlers for various types of pages.
*/
enum outcome {
IGNORED, /* Error: cannot be handled */
FAILED, /* Error: handling failed */
DELAYED, /* Will be handled later */
RECOVERED, /* Successfully recovered */
};
So adding a reference to here looks better to me.
Thanks,
Naoya Horiguchi
> + */
> +TRACE_EVENT(memory_failure_event,
> + TP_PROTO(const unsigned long pfn,
> + const char *action,
> + const char *result),
> +
> + TP_ARGS(pfn, action, result),
> +
> + TP_STRUCT__entry(
> + __field(unsigned long, pfn)
> + __string(action, action)
> + __string(result, result)
> + ),
> +
> + TP_fast_assign(
> + __entry->pfn = pfn;
> + __assign_str(action, action);
> + __assign_str(result, result);
> + ),
> +
> + TP_printk("pfn %#lx: %s page recovery: %s",
> + __entry->pfn,
> + __get_str(action),
> + __get_str(result)
> + )
> +);
> #endif /* _TRACE_HW_EVENT_MC_H */
>
> /* This part must be outside protection */
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index d487f8d..86a9cce 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -56,6 +56,7 @@
> #include <linux/mm_inline.h>
> #include <linux/kfifo.h>
> #include "internal.h"
> +#include <ras/ras_event.h>
>
> int sysctl_memory_failure_early_kill __read_mostly = 0;
>
> @@ -837,6 +838,8 @@ static struct page_state {
> */
> static void action_result(unsigned long pfn, char *msg, int result)
> {
> + trace_memory_failure_event(pfn, msg, action_name[result]);
> +
> pr_err("MCE %#lx: %s page recovery: %s\n",
> pfn, msg, action_name[result]);
> }
> --
> 1.7.1
>
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