Re: [PATCH v3 3/3] mce, acpi/apei: Soft-offline a page on firmware GHES notification

Borislav Petkov
2013-07-03T14:44:54Z

On Tue, Jul 02, 2013 at 05:02:48PM +0530, Naveen N. Rao wrote:
> Here is the updated patch. I also added printk_ratelimit() in line with the
> rest of the GHES code.
>
> Thanks,
> Naveen
>
> --
> If the firmware indicates in GHES error data entry that the error threshold
> has exceeded for a corrected error event, then we try to soft-offline the
> page. This could be called in interrupt context, so we queue this up similar
> to how we handle memory failure scenarios.
>
>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> ---
> drivers/acpi/apei/ghes.c | 38 +++++++++++++++++++++++++++++---------
> include/linux/mm.h | 1 +
> mm/memory-failure.c | 5 ++++-
> 3 files changed, 34 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> index fcd7d91..74ef688 100644
> --- a/drivers/acpi/apei/ghes.c
> +++ b/drivers/acpi/apei/ghes.c
> @@ -409,6 +409,34 @@ static void ghes_clear_estatus(struct ghes *ghes)
> ghes->flags &= ~GHES_TO_CLEAR;
> }
>
> +static void ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, int sev)
> +{
> +#ifdef CONFIG_ACPI_APEI_MEMORY_FAILURE
> + int sec_sev = ghes_severity(gdata->error_severity);
> + struct cper_sec_mem_err *mem_err;
> + mem_err = (struct cper_sec_mem_err *)(gdata+1);

A newline here please. Also, spaces around '+'.

> + if (sec_sev == GHES_SEV_CORRECTED &&
> + (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED) &&
> + (mem_err->validation_bits & CPER_MEM_VALID_PHYSICAL_ADDRESS)) {
> + unsigned long pfn;

This pfn is defined twice, move it up to the beginning of the function.

> + pfn = mem_err->physical_addr >> PAGE_SHIFT;
> + if (pfn_valid(pfn))
> + memory_failure_queue(pfn, 0, MF_SOFT_OFFLINE);
> + else if (printk_ratelimit())
> + pr_warning(FW_WARN GHES_PFX

WARNING: Prefer printk_ratelimited or pr_<level>_ratelimited to printk_ratelimit
#35: FILE: drivers/acpi/apei/ghes.c:425:
+ else if (printk_ratelimit())

Please run your patches through checkpatch.pl first.

This requested change will even simplify the code (ontop of your patch):

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 74ef6882bca9..87e11d468f6b 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -422,10 +422,10 @@ static void ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, int
pfn = mem_err->physical_addr >> PAGE_SHIFT;
if (pfn_valid(pfn))
memory_failure_queue(pfn, 0, MF_SOFT_OFFLINE);
- else if (printk_ratelimit())
- pr_warning(FW_WARN GHES_PFX
- "Invalid address in generic error data: %#llx\n",
- mem_err->physical_addr);
+ else
+ pr_warn_ratelimited(FW_WARN GHES_PFX
+ "Invalid address in generic error data: %#llx\n",
+ mem_err->physical_addr);
}
if (sev == GHES_SEV_RECOVERABLE &&
sec_sev == GHES_SEV_RECOVERABLE &&
---

> + "Invalid address in generic error data: %#llx\n",
> + mem_err->physical_addr);
> + }
> + if (sev == GHES_SEV_RECOVERABLE &&
> + sec_sev == GHES_SEV_RECOVERABLE &&
> + mem_err->validation_bits & CPER_MEM_VALID_PHYSICAL_ADDRESS) {
> + unsigned long pfn;
> + pfn = mem_err->physical_addr >> PAGE_SHIFT;
> + memory_failure_queue(pfn, 0, 0);
> + }
> +#endif
> +}
> +
> static void ghes_do_proc(struct ghes *ghes,
> const struct acpi_hest_generic_status *estatus)
> {
> @@ -428,15 +456,7 @@ static void ghes_do_proc(struct ghes *ghes,
> apei_mce_report_mem_error(sev == GHES_SEV_CORRECTED,
> mem_err);
> #endif
> -#ifdef CONFIG_ACPI_APEI_MEMORY_FAILURE
> - if (sev == GHES_SEV_RECOVERABLE &&
> - sec_sev == GHES_SEV_RECOVERABLE &&
> - mem_err->validation_bits & CPER_MEM_VALID_PHYSICAL_ADDRESS) {
> - unsigned long pfn;
> - pfn = mem_err->physical_addr >> PAGE_SHIFT;
> - memory_failure_queue(pfn, 0, 0);
> - }
> -#endif
> + ghes_handle_memory_failure(gdata, sev);
> }
> #ifdef CONFIG_ACPI_APEI_PCIEAER
> else if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index e0c8528..958e9efd 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1784,6 +1784,7 @@ enum mf_flags {
> MF_COUNT_INCREASED = 1 << 0,
> MF_ACTION_REQUIRED = 1 << 1,
> MF_MUST_KILL = 1 << 2,
> + MF_SOFT_OFFLINE = 1 << 3,
> };
> extern int memory_failure(unsigned long pfn, int trapno, int flags);
> extern void memory_failure_queue(unsigned long pfn, int trapno, int flags);
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index ceb0c7f..0d6717e 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1286,7 +1286,10 @@ static void memory_failure_work_func(struct work_struct *work)
> spin_unlock_irqrestore(&mf_cpu->lock, proc_flags);
> if (!gotten)
> break;
> - memory_failure(entry.pfn, entry.trapno, entry.flags);
> + if (entry.flags & MF_SOFT_OFFLINE)
> + soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
> + else
> + memory_failure(entry.pfn, entry.trapno, entry.flags);

The rest looks ok to me.

I'm guessing this has been tested by injecting errors...?

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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