drivers/firmware/arm_scmi/driver.c | 21 ++++++++++++++++++++ include/trace/events/scmi.h | 31 ++++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+)
Hi,
after a few recent troubles handling too strictly out-of-spec replies from
SCMI servers deployed in the wild, I though it could have been useful to
have a basic way to dump at will the effective full payloads of successfuly
transmitted/received SCMI messages.
The existing SCMI traces already collect a bunch of information about SCMI
message exchanges but they do NOT keep any payload information: this is
certainly preferable most of the time since dumping full SCMI messages to
the trace buffer involves a full copy of the payload.
For this reason I added a new distinct trace_scmi_msg_dump with this series
in order to be able to selectively enable at will message dumping only when
required.
Only successfully transmitted and received (valid) xfers are dumped.
At first I was thinking about just dumping raw header and payload, but in
order to make the log a bit more human readable (without the need of
tooling to parse the log), I added some parsing/interpretation of the
header, so that the final result is something like:
root@deb-guest:~# echo 1 > /sys/kernel/debug/tracing/events/scmi/scmi_msg_dump/enable
root@deb-guest:~# cat /sys/kernel/debug/tracing/trace_pipe
(my annotations non on traces =>>) proto type cmd seq status payload
| | | | | |
++ cmd/reply | | | | | |
cat-224 [002] ..... 147.755847: scmi_msg_dump: [0x15]:CMND:[0x06]:[0021]:[0]: 0000000000000000
<idle>-0 [000] d.h2. 147.758311: scmi_msg_dump: [0x15]:RESP:[0x06]:[0021]:[0]: 25000000000000000000000000000000
++ cmd/reply/delayed
cat-223 [001] ..... 122.384192: scmi_msg_dump: [0x15]:CMND:[0x06]:[0020]:[0]: 0100000001000000
<idle>-0 [000] d.h2. 122.405548: scmi_msg_dump: [0x15]:RESP:[0x06]:[0020]:[0]:
<idle>-0 [000] d.h2. 122.425839: scmi_msg_dump: [0x15]:DLYD:[0x06]:[0020]:[0]: 01000000a05a320000000000efbeaddefecafeca
++ enable notif/notif
iio_generic_buf-233 [003] ..... 522.399690: scmi_msg_dump: [0x15]:CMND:[0x0A]:[0024]:[0]: 0800000003000000
<idle>-0 [000] dNh2. 522.417778: scmi_msg_dump: [0x15]:RESP:[0x0A]:[0024]:[0]: 00000000
<idle>-0 [000] d.h2. 522.500945: scmi_msg_dump: [0x15]:NOTI:[0x01]:[0000]:[0]: 000000000800000008daffffffffffff0040d3a45d46fb1610daffffffffffff0040d3a45d46fb1618daffffffffffff0040d3a45d46fb16
Payload is dumped as it comes through byte-by-byte without any endianity
conversion to avoid further load on the system.
Any thoughs ?
Thanks,
Cristian
Cristian Marussi (2):
include: trace: Add SCMI full message tracing
firmware: arm_scmi: Use new SCMI full message tracing
drivers/firmware/arm_scmi/driver.c | 21 ++++++++++++++++++++
include/trace/events/scmi.h | 31 ++++++++++++++++++++++++++++++
2 files changed, 52 insertions(+)
--
2.32.0
On Thu, Jun 23, 2022 at 10:55 AM Cristian Marussi
<cristian.marussi@arm.com> wrote:
>
> Hi,
>
> after a few recent troubles handling too strictly out-of-spec replies from
> SCMI servers deployed in the wild, I though it could have been useful to
> have a basic way to dump at will the effective full payloads of successfuly
> transmitted/received SCMI messages.
>
> The existing SCMI traces already collect a bunch of information about SCMI
> message exchanges but they do NOT keep any payload information: this is
> certainly preferable most of the time since dumping full SCMI messages to
> the trace buffer involves a full copy of the payload.
>
> For this reason I added a new distinct trace_scmi_msg_dump with this series
> in order to be able to selectively enable at will message dumping only when
> required.
>
> Only successfully transmitted and received (valid) xfers are dumped.
>
> At first I was thinking about just dumping raw header and payload, but in
> order to make the log a bit more human readable (without the need of
> tooling to parse the log), I added some parsing/interpretation of the
> header, so that the final result is something like:
>
> root@deb-guest:~# echo 1 > /sys/kernel/debug/tracing/events/scmi/scmi_msg_dump/enable
> root@deb-guest:~# cat /sys/kernel/debug/tracing/trace_pipe
>
> (my annotations non on traces =>>) proto type cmd seq status payload
> | | | | | |
> ++ cmd/reply | | | | | |
> cat-224 [002] ..... 147.755847: scmi_msg_dump: [0x15]:CMND:[0x06]:[0021]:[0]: 0000000000000000
> <idle>-0 [000] d.h2. 147.758311: scmi_msg_dump: [0x15]:RESP:[0x06]:[0021]:[0]: 25000000000000000000000000000000
>I'll probably still use a script, but
as you are keep
>
> ++ cmd/reply/delayed
> cat-223 [001] ..... 122.384192: scmi_msg_dump: [0x15]:CMND:[0x06]:[0020]:[0]: 0100000001000000
> <idle>-0 [000] d.h2. 122.405548: scmi_msg_dump: [0x15]:RESP:[0x06]:[0020]:[0]:
> <idle>-0 [000] d.h2. 122.425839: scmi_msg_dump: [0x15]:DLYD:[0x06]:[0020]:[0]: 01000000a05a320000000000efbeaddefecafeca
>
>
> ++ enable notif/notif
> iio_generic_buf-233 [003] ..... 522.399690: scmi_msg_dump: [0x15]:CMND:[0x0A]:[0024]:[0]: 0800000003000000
> <idle>-0 [000] dNh2. 522.417778: scmi_msg_dump: [0x15]:RESP:[0x0A]:[0024]:[0]: 00000000
> <idle>-0 [000] d.h2. 522.500945: scmi_msg_dump: [0x15]:NOTI:[0x01]:[0000]:[0]: 000000000800000008daffffffffffff0040d3a45d46fb1610daffffffffffff0040d3a45d46fb1618daffffffffffff0040d3a45d46fb16
>
> Payload is dumped as it comes through byte-by-byte without any endianity
> conversion to avoid further load on the system.
>
> Any thoughs ?
Hi Christian,
I haven't tested this but the format looks good to me. I have a
couple of minor suggestions
below.
As all numbers are hex, consider dropping the '0x'. BTW, the seq
value (eg [0020]) is hex but does not have '0x'.
Some TP_printk()s use this style:
scmi_msg_dump: pt=15 t=CMND cmd=06 seq=0021 s=0 pyld=12345678abcdef
which allows one to easily grep, for example, for all non-zero returns
grep 's=[^0]'
This format is also easy to parse with a script: strip the preamble,
split on whitespace, and then split on '=' to get the [key, value]
pairs.
Thanks,
Jim Quinlan
Broadcom STB
>
> Thanks,
> Cristian
>
> Cristian Marussi (2):
> include: trace: Add SCMI full message tracing
> firmware: arm_scmi: Use new SCMI full message tracing
>
> drivers/firmware/arm_scmi/driver.c | 21 ++++++++++++++++++++
> include/trace/events/scmi.h | 31 ++++++++++++++++++++++++++++++
> 2 files changed, 52 insertions(+)
>
> --
> 2.32.0
>
On Mon, Jun 27, 2022 at 03:05:57PM -0400, Jim Quinlan wrote: > On Thu, Jun 23, 2022 at 10:55 AM Cristian Marussi > <cristian.marussi@arm.com> wrote: > > > > Hi, > > > > after a few recent troubles handling too strictly out-of-spec replies from > > SCMI servers deployed in the wild, I though it could have been useful to > > have a basic way to dump at will the effective full payloads of successfuly > > transmitted/received SCMI messages. > > > > The existing SCMI traces already collect a bunch of information about SCMI > > message exchanges but they do NOT keep any payload information: this is > > certainly preferable most of the time since dumping full SCMI messages to > > the trace buffer involves a full copy of the payload. > > > > For this reason I added a new distinct trace_scmi_msg_dump with this series > > in order to be able to selectively enable at will message dumping only when > > required. > > > > Only successfully transmitted and received (valid) xfers are dumped. > > > > At first I was thinking about just dumping raw header and payload, but in > > order to make the log a bit more human readable (without the need of > > tooling to parse the log), I added some parsing/interpretation of the > > header, so that the final result is something like: > > > > root@deb-guest:~# echo 1 > /sys/kernel/debug/tracing/events/scmi/scmi_msg_dump/enable > > root@deb-guest:~# cat /sys/kernel/debug/tracing/trace_pipe > > > > (my annotations non on traces =>>) proto type cmd seq status payload > > | | | | | | > > ++ cmd/reply | | | | | | > > cat-224 [002] ..... 147.755847: scmi_msg_dump: [0x15]:CMND:[0x06]:[0021]:[0]: 0000000000000000 > > <idle>-0 [000] d.h2. 147.758311: scmi_msg_dump: [0x15]:RESP:[0x06]:[0021]:[0]: 25000000000000000000000000000000 > >I'll probably still use a script, but > as you are keep > > > > ++ cmd/reply/delayed > > cat-223 [001] ..... 122.384192: scmi_msg_dump: [0x15]:CMND:[0x06]:[0020]:[0]: 0100000001000000 > > <idle>-0 [000] d.h2. 122.405548: scmi_msg_dump: [0x15]:RESP:[0x06]:[0020]:[0]: > > <idle>-0 [000] d.h2. 122.425839: scmi_msg_dump: [0x15]:DLYD:[0x06]:[0020]:[0]: 01000000a05a320000000000efbeaddefecafeca > > > > > > ++ enable notif/notif > > iio_generic_buf-233 [003] ..... 522.399690: scmi_msg_dump: [0x15]:CMND:[0x0A]:[0024]:[0]: 0800000003000000 > > <idle>-0 [000] dNh2. 522.417778: scmi_msg_dump: [0x15]:RESP:[0x0A]:[0024]:[0]: 00000000 > > <idle>-0 [000] d.h2. 522.500945: scmi_msg_dump: [0x15]:NOTI:[0x01]:[0000]:[0]: 000000000800000008daffffffffffff0040d3a45d46fb1610daffffffffffff0040d3a45d46fb1618daffffffffffff0040d3a45d46fb16 > > > > Payload is dumped as it comes through byte-by-byte without any endianity > > conversion to avoid further load on the system. > > > > Any thoughs ? > > Hi Christian, > I haven't tested this but the format looks good to me. I have a > couple of minor suggestions > below. > Hi Jim, thanks for having a look. > As all numbers are hex, consider dropping the '0x'. BTW, the seq > value (eg [0020]) is hex but does not have '0x'. > Yes indeed, good point. > Some TP_printk()s use this style: > > scmi_msg_dump: pt=15 t=CMND cmd=06 seq=0021 s=0 pyld=12345678abcdef > > which allows one to easily grep, for example, for all non-zero returns > > grep 's=[^0]' > > This format is also easy to parse with a script: strip the preamble, > split on whitespace, and then split on '=' to get the [key, value] > pairs. In fact having a grep-friendly format is better. Thanks for your feedback, I'll wait to see if someone else wants to chime in and repost. Thanks, Cristian
On Wed, Jun 29, 2022 at 07:19:32PM +0100, Cristian Marussi wrote: > On Mon, Jun 27, 2022 at 03:05:57PM -0400, Jim Quinlan wrote: [...] > > This format is also easy to parse with a script: strip the preamble, > > split on whitespace, and then split on '=' to get the [key, value] > > pairs. > > In fact having a grep-friendly format is better. > > Thanks for your feedback, I'll wait to see if someone else wants to > chime in and repost. > I agree with Jim's proposal, please update and send the patch. -- Regards, Sudeep
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