On Wed, 2015-15-07 at 04:22:06 UTC, Kamalesh Babulal wrote:
> Kernel prints respective warnings about various EPOW events for
> user information/action after parsing EPOW interrupts.Prompting
> user to take action depending upon the severity of the event.
>
> At times EPOW reset event warning, such as below could flood
> kernel log, over a period of time.
>
> May 25 03:46:34 alp kernel: Non critical power or cooling issue cleared
> May 25 03:46:52 alp kernel: Non critical power or cooling issue cleared
> May 25 03:53:48 alp kernel: Non critical power or cooling issue cleared
> May 25 03:55:46 alp kernel: Non critical power or cooling issue cleared
> May 25 03:56:34 alp kernel: Non critical power or cooling issue cleared
> May 25 03:59:04 alp kernel: Non critical power or cooling issue cleared
> May 25 04:02:01 alp kernel: Non critical power or cooling issue cleared
> May 25 04:04:24 alp kernel: Non critical power or cooling issue cleared
> May 25 04:07:18 alp kernel: Non critical power or cooling issue cleared
> May 25 04:13:04 alp kernel: Non critical power or cooling issue cleared
> May 25 04:22:04 alp kernel: Non critical power or cooling issue cleared
> May 25 04:22:26 alp kernel: Non critical power or cooling issue cleared
> May 25 04:22:36 alp kernel: Non critical power or cooling issue cleared
>
> This patch avoids these multiple EPOW reset warnings by using a boolean
> flag. This flag is initialized to false and is set to true upon arrival
> of EPOW event. This same flag is checked and reset during EPOW_RESET
> scenario to filter out valid EPOW reset events and avoid multiple warning
> logs.
Why are we even getting these reset events when nothing has happened?
> Also, merged adjacent pr_err/pr_emerg into single one to reduce
> the number of lines printed per warning.
>
> Suggested-by: Vipin K Parashar <vi...@linux.vnet.ibm.com>
> [Vipin: edited the changelog]
> Cc: Anshuman Khandual <khand...@linux.vnet.ibm.com>
> Cc: Anton Blanchard <an...@samba.org>
> Cc: Michael Ellerman <m...@ellerman.id.au>
> Signed-off-by: Kamalesh Babulal <kamal...@linux.vnet.ibm.com>
> ---
> v3 Changes:
> - Limit warning printed by EPOW RESET event, by guarding it with bool flag.
> Instead of rate limiting all the EPOW events.
>
> v2 Changes:
> - Merged multiple adjacent pr_err/pr_emerg into single line to reduce
> multi-line
> warnings, based on Michael's comments.
>
> arch/powerpc/platforms/pseries/ras.c | 25 +++++++++++++++++--------
> 1 file changed, 17 insertions(+), 8 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/ras.c
> b/arch/powerpc/platforms/pseries/ras.c
> index 02e4a17..b30396a 100644
> --- a/arch/powerpc/platforms/pseries/ras.c
> +++ b/arch/powerpc/platforms/pseries/ras.c
> @@ -40,6 +40,9 @@ static int ras_check_exception_token;
> #define EPOW_SENSOR_TOKEN 9
> #define EPOW_SENSOR_INDEX 0
>
> +/* Flag to limit EPOW RESET warning. */
> +static bool epow_state;
This name is terrible, it doesn't give me any hint to what it means.
But really it should be a counter, not a boolean.
We could have multiple EPOW events come in and then later get the reset events
for them, couldn't we?
So what about:
static unsigned epow_event_depth;
And then below:
> @@ -145,21 +148,27 @@ static void rtas_parse_epow_errlog(struct
> rtas_error_log *log)
>
epow_event_depth++;
switch (action_code) {
case EPOW_RESET:
if (epow_event_depth)
epow_event_depth--;
if (epow_event_depth)
> + pr_err("Non critical power or cooling issue cleared");
> break;
And that's all you need.
> case EPOW_WARN_COOLING:
> - pr_err("Non critical cooling issue reported by firmware");
> - pr_err("Check RTAS error log for details");
> + pr_err("Non critical cooling issue reported by firmware, "
> + "Check RTAS error log for details");
This should be:
pr_err("Non-critical cooling issue reported by firmware, check
RTAS error log for details.\n");
But that's too long, so how about:
pr_err("Non-critical cooling issue reported, check RTAS error
log for details.\n");
And if it's non-critical it shouldn't be pr_err(), it should be pr_info().
Similarly for all the other messages.
cheers
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