linux-kernel - Re: [PATCH v7 11/17] PCI/AER: Combine trace_aer

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Message-ID: <20250521104642.00003648@huawei.com>
Date: Wed, 21 May 2025 10:46:42 +0100
From: Jonathan Cameron <Jonathan.Cameron@...wei.com>
To: Bjorn Helgaas <helgaas@...nel.org>
CC: <linux-pci@...r.kernel.org>, Jon Pan-Doh <pandoh@...gle.com>, "Karolina
 Stolarek" <karolina.stolarek@...cle.com>, Weinan Liu <wnliu@...gle.com>,
	Martin Petersen <martin.petersen@...cle.com>, Ben Fuller
	<ben.fuller@...cle.com>, Drew Walton <drewwalton@...rosoft.com>, "Anil
 Agrawal" <anilagrawal@...a.com>, Tony Luck <tony.luck@...el.com>, Ilpo
 Järvinen <ilpo.jarvinen@...ux.intel.com>, "Sathyanarayanan
 Kuppuswamy" <sathyanarayanan.kuppuswamy@...ux.intel.com>, Lukas Wunner
	<lukas@...ner.de>, Sargun Dhillon <sargun@...a.com>, "Paul E . McKenney"
	<paulmck@...nel.org>, Mahesh J Salgaonkar <mahesh@...ux.ibm.com>, "Oliver
 O'Halloran" <oohall@...il.com>, Kai-Heng Feng <kaihengf@...dia.com>, "Keith
 Busch" <kbusch@...nel.org>, Robert Richter <rrichter@....com>, Terry Bowman
	<terry.bowman@....com>, Shiju Jose <shiju.jose@...wei.com>, Dave Jiang
	<dave.jiang@...el.com>, <linux-kernel@...r.kernel.org>,
	<linuxppc-dev@...ts.ozlabs.org>, Bjorn Helgaas <bhelgaas@...gle.com>,
	Krzysztof Wilczyński <kwilczynski@...nel.org>
Subject: Re: [PATCH v7 11/17] PCI/AER: Combine trace_aer_event() with
 statistics updates

On Tue, 20 May 2025 16:50:28 -0500
Bjorn Helgaas <helgaas@...nel.org> wrote:

> From: Bjorn Helgaas <bhelgaas@...gle.com>
> 
> As with the AER statistics, we always want to emit trace events, even if
> the actual dmesg logging is rate limited.
> 
> Call trace_aer_event() directly from pci_dev_aer_stats_incr(), where we
> update the statistics.
> 
> Signed-off-by: Bjorn Helgaas <bhelgaas@...gle.com>
> Tested-by: Krzysztof Wilczyński <kwilczynski@...nel.org>
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>

Hmm. This runs a bit counter to what I liked in previous patch.
Whilst convenient to issue trace points in the stats update function
it's not obvious behavior given naming.  Maybe just duplicate the call
and call it immediately after the pci_dev_aer_stats_incr() calls?

> ---
>  drivers/pci/pcie/aer.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index 53b7559564a9..ec63825a808e 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -625,6 +625,9 @@ static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
>  	u64 *counter = NULL;
>  	struct aer_stats *aer_stats = pdev->aer_stats;
>  
> +	trace_aer_event(pci_name(pdev), (info->status & ~info->mask),
> +			info->severity, info->tlp_header_valid, &info->tlp);
> +
>  	if (!aer_stats)
>  		return;
>  
> @@ -741,9 +744,6 @@ void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
>  out:
>  	if (info->id && info->error_dev_num > 1 && info->id == id)
>  		pci_err(dev, "  Error of this Agent is reported first\n");
> -
> -	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
> -			info->severity, info->tlp_header_valid, &info->tlp);
>  }
>  
>  #ifdef CONFIG_ACPI_APEI_PCIEAER
> @@ -782,6 +782,9 @@ void pci_print_aer(struct pci_dev *dev, int aer_severity,
>  
>  	info.status = status;
>  	info.mask = mask;
> +	info.tlp_header_valid = tlp_header_valid;
> +	if (tlp_header_valid)
> +		info.tlp = aer->header_log;
>  
>  	pci_dev_aer_stats_incr(dev, &info);
>  
> @@ -799,9 +802,6 @@ void pci_print_aer(struct pci_dev *dev, int aer_severity,
>  
>  	if (tlp_header_valid)
>  		pcie_print_tlp_log(dev, &aer->header_log, dev_fmt("  "));
> -
> -	trace_aer_event(pci_name(dev), (status & ~mask),
> -			aer_severity, tlp_header_valid, &aer->header_log);
>  }
>  EXPORT_SYMBOL_NS_GPL(pci_print_aer, "CXL");
>