On Mon, 7 May 2018 17:21:37 -0500
Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> [+cc Steve, Alex]
>
> On Mon, Apr 02, 2018 at 11:47:08AM -0400, Thomas Tai wrote:
> > When a PCIe AER occurs, the TLP header information is
> > printed in the kernel message but it is missing from
> > the tracepoint. A userspace program can use this information
> > in the tracepoint to better analyze problems.
> >
> > Example tracepoint output:
> > aer_event: 0000:01:00.0
> > PCIe Bus Error: severity=Uncorrected, non-fatal, Completer Abort
> > TLP Header={0x0,0x1,0x2,0x3}
> >
> > Signed-off-by: Thomas Tai <thomas.tai@xxxxxxxxxx>
>
> I tentatively applied this to pci/aer for v4.18, thanks!
>
> Steve, let me know if you have any comments.
>
> Alex, I just copied you because you've been unifying the AER native and
> CPER paths, and this is another case of code that appears in both paths.
> FYI only, no action required :)
>
> > ---
> > drivers/pci/pcie/aer/aerdrv_errprint.c | 4 ++--
> > include/ras/ras_event.h | 20 ++++++++++++++++----
> > 2 files changed, 18 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/pci/pcie/aer/aerdrv_errprint.c b/drivers/pci/pcie/aer/aerdrv_errprint.c
> > index 6a352e638699..0a78a773bd25 100644
> > --- a/drivers/pci/pcie/aer/aerdrv_errprint.c
> > +++ b/drivers/pci/pcie/aer/aerdrv_errprint.c
> > @@ -192,7 +192,7 @@ void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
> > pci_err(dev, " Error of this Agent(%04x) is reported first\n", id);
> >
> > trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
> > - info->severity);
> > + info->severity, info->tlp_header_valid, &info->tlp);
> > }
> >
> > void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
> > @@ -252,6 +252,6 @@ void cper_print_aer(struct pci_dev *dev, int aer_severity,
> > __print_tlp_header(dev, &aer->header_log);
> >
> > trace_aer_event(dev_name(&dev->dev), (status & ~mask),
> > - aer_severity);
> > + aer_severity, tlp_header_valid, &aer->header_log);
> > }
> > #endif
> > diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h
> > index 9c689868eb4d..90f59556f595 100644
> > --- a/include/ras/ras_event.h
> > +++ b/include/ras/ras_event.h
> > @@ -298,30 +298,42 @@ TRACE_EVENT(non_standard_event,
> > TRACE_EVENT(aer_event,
> > TP_PROTO(const char *dev_name,
> > const u32 status,
> > - const u8 severity),
> > + const u8 severity,
> > + const u32 tlp_header_valid,
> > + struct aer_header_log_regs *tlp),
> >
> > - TP_ARGS(dev_name, status, severity),
> > + TP_ARGS(dev_name, status, severity, tlp_header_valid, tlp),
> >
> > TP_STRUCT__entry(
> > __string( dev_name, dev_name )
> > __field( u32, status )
> > __field( u8, severity )
> > + __field( u32, tlp_header_valid)
I'm guessing tlp_header_valid is just a boolean. It's after severity
which is just one byte long. Why not make this one byte as well,
otherwise you are wasting 3 bytes.
> > + __array( u32, buf, 4 )
> > ),
> >
> > TP_fast_assign(
> > __assign_str(dev_name, dev_name);
> > __entry->status = status;
> > __entry->severity = severity;
> > + __entry->tlp_header_valid = tlp_header_valid;
> > + __entry->buf[0] = tlp->dw0;
> > + __entry->buf[1] = tlp->dw1;
> > + __entry->buf[2] = tlp->dw2;
> > + __entry->buf[3] = tlp->dw3;
Should this assignment be dependent on whether or not tlp_header_valid
is true? Could tlp be pointing to some random memory if it isn't? What
about:
if ((__entry->tlp_header_valid = tlp_header_valid)) {
__entry->buf[0] = tlp->dw0;
__entry->buf[1] = tlp->dw1;
__entry->buf[2] = tlp->dw2;
__entry->buf[3] = tlp->dw3;
}
> > ),
> >
> > - TP_printk("%s PCIe Bus Error: severity=%s, %s\n",
> > + TP_printk("%s PCIe Bus Error: severity=%s, %s, TLP Header=%s\n",
> > __get_str(dev_name),
> > __entry->severity == AER_CORRECTABLE ? "Corrected" :
> > __entry->severity == AER_FATAL ?
> > "Fatal" : "Uncorrected, non-fatal",
> > __entry->severity == AER_CORRECTABLE ?
> > __print_flags(__entry->status, "|", aer_correctable_errors) :
> > - __print_flags(__entry->status, "|", aer_uncorrectable_errors))
> > + __print_flags(__entry->status, "|", aer_uncorrectable_errors),
> > + __entry->tlp_header_valid ?
> > + __print_array(__entry->buf, 4, sizeof(unsigned int)) :
Note, "sizeof" will be shown in the format file that perf and trace-cmd
read to parse this event. They currently do not know how to parse that
(although I could add that in the future).
Since sizeof(unsigned int) is always 4 in Linux, just use 4.
__print_array(__entry->buf, 4, 4)
-- Steve
> > + "Not available")
> > );
> >
> > /*
> > --
> > 2.14.1
> >
