linux-nvdimm.lists.01.org archive mirror
 help / color / mirror / Atom feed
From: Ira Weiny <ira.weiny@intel.com>
To: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-nvdimm@lists.01.org,
	"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
	Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: [PATCH v3] powerpc/papr_scm: Reduce error severity if nvdimm stats inaccessible
Date: Sat, 8 May 2021 08:11:30 -0700	[thread overview]
Message-ID: <20210508151130.GK1904484@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <20210508043642.114076-1-vaibhav@linux.ibm.com>

On Sat, May 08, 2021 at 10:06:42AM +0530, Vaibhav Jain wrote:
> Currently drc_pmem_qeury_stats() generates a dev_err in case
> "Enable Performance Information Collection" feature is disabled from
> HMC or performance stats are not available for an nvdimm. The error is
> of the form below:
> 
> papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Failed to query
> 	 performance stats, Err:-10
> 
> This error message confuses users as it implies a possible problem
> with the nvdimm even though its due to a disabled/unavailable
> feature. We fix this by explicitly handling the H_AUTHORITY and
> H_UNSUPPORTED errors from the H_SCM_PERFORMANCE_STATS hcall.
> 
> In case of H_AUTHORITY error an info message is logged instead of an
> error, saying that "Permission denied while accessing performance
> stats" and an EPERM error is returned back.
> 
> In case of H_UNSUPPORTED error we return a EOPNOTSUPP error back from
> drc_pmem_query_stats() indicating that performance stats-query
> operation is not supported on this nvdimm.
> 
> Fixes: 2d02bf835e57('powerpc/papr_scm: Fetch nvdimm performance stats from PHYP')
> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> ---
> Changelog
> 
> v3:
> * Return EOPNOTSUPP error in case of H_UNSUPPORTED [ Ira ]
> * Return EPERM in case of H_AUTHORITY [ Ira ]
> * Updated patch description
> 
> v2:
> * Updated the message logged in case of H_AUTHORITY error [ Ira ]
> * Switched from dev_warn to dev_info in case of H_AUTHORITY error.
> * Instead of -EPERM return -EACCESS for H_AUTHORITY error.
> * Added explicit handling of H_UNSUPPORTED error.
> ---
>  arch/powerpc/platforms/pseries/papr_scm.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
> index ef26fe40efb0..e2b69cc3beaf 100644
> --- a/arch/powerpc/platforms/pseries/papr_scm.c
> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
> @@ -310,6 +310,13 @@ static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
>  		dev_err(&p->pdev->dev,
>  			"Unknown performance stats, Err:0x%016lX\n", ret[0]);
>  		return -ENOENT;
> +	} else if (rc == H_AUTHORITY) {
> +		dev_info(&p->pdev->dev,
> +			 "Permission denied while accessing performance stats");
> +		return -EPERM;
> +	} else if (rc == H_UNSUPPORTED) {
> +		dev_dbg(&p->pdev->dev, "Performance stats unsupported\n");
> +		return -EOPNOTSUPP;
>  	} else if (rc != H_SUCCESS) {
>  		dev_err(&p->pdev->dev,
>  			"Failed to query performance stats, Err:%lld\n", rc);
> -- 
> 2.31.1
> 
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org

  reply	other threads:[~2021-05-08 15:11 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-08  4:36 Vaibhav Jain
2021-05-08 15:11 ` Ira Weiny [this message]
2021-05-19  7:06 ` kajoljain

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210508151130.GK1904484@iweiny-DESK2.sc.intel.com \
    --to=ira.weiny@intel.com \
    --cc=aneesh.kumar@linux.ibm.com \
    --cc=linux-nvdimm@lists.01.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mpe@ellerman.id.au \
    --cc=vaibhav@linux.ibm.com \
    --subject='Re: [PATCH v3] powerpc/papr_scm: Reduce error severity if nvdimm stats inaccessible' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).