Re: retrieving non-numeral fields from an event record

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, 22 Aug 2022 15:21:01 -0700
Dave Jiang <dave.jiang@xxxxxxxxx> wrote:

> On 8/22/2022 3:18 PM, Steven Rostedt wrote:
> > On Mon, 22 Aug 2022 14:48:30 -0700
> > Dave Jiang <dave.jiang@xxxxxxxxx> wrote:
> >  
> >> Attempting to use libtraceevent to retrieve fields from events. For example here's the event I'm trying to parse:
> >>
> >>    check-events.sh-5983    [002] ..... 261848.250238: cxl_dram_event: cxl_mem.7: Fatal time=0 id=b3cb1
> >> d60-069c-ab4e-b8af-4e9bfb5c9624 handle=1 related_handle=0 hdr_flags='Performance Degraded': phys_add
> >> r=8000 volatile=FALSE desc='Threshold event' type='Invalid Address' trans_type='Internal Media Scrub
> >> ' channel=1 rank=0 nibble_mask=0 bank_group=5 bank=2 row=0 column=1024 cor_mask=00 00 00 00 00 00 00
> >>    00 00 00 00 00 00 00 00 0000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 valid_flags='CHANNEL|BANK
> >>    GROUP|BANK|COLUMN'
> >>
> >> Here's me iterating through all the fields and using tep_get_field_raw() trying to retrieve the fields. It appears that
> >> if the field is a string type I'm not able to retrieve the field and the error written back in the seq file is
> >> "CANT FIND FIELD". Am I doing something wrong or using the wrong API to retrieve those type of fields?
> >>  
> > What's the format for this event? That is, what is the output of :
> >
> >   trace-cmd list -e cxl_dram_event -F
> >
> > ?  
> 
> #trace-cmd list -e cxl_dram_event -F
> system: cxl_events
> name: cxl_dram_event
> ID: 2325
> format:
>          field:unsigned short common_type;       offset:0;       size:2; signed:0;
>          field:unsigned char common_flags;       offset:2;       size:1; signed:0;
>          field:unsigned char common_preempt_count;       offset:3;       size:1; signed:0;
>          field:int common_pid;   offset:4;       size:4; signed:1;
> 
>          field:__data_loc char[] dev_name;       offset:8;       size:4; signed:1;
>          field:int log;  offset:12;      size:4; signed:1;
>          field:u8 id[16];        offset:16;      size:16;        signed:0;
>          field:u32 flags;        offset:32;      size:4; signed:0;
>          field:u16 handle;       offset:36;      size:2; signed:0;
>          field:u16 related_handle;       offset:38;      size:2; signed:0;
>          field:u64 timestamp;    offset:40;      size:8; signed:0;
>          field:u64 phys_addr;    offset:48;      size:8; signed:0;
>          field:u8 descriptor;    offset:56;      size:1; signed:0;
>          field:u8 type;  offset:57;      size:1; signed:0;
>          field:u8 transaction_type;      offset:58;      size:1; signed:0;
>          field:u8 channel;       offset:59;      size:1; signed:0;
>          field:u16 validity_flags;       offset:60;      size:2; signed:0;
>          field:u16 column;       offset:62;      size:2; signed:0;
>          field:u32 nibble_mask;  offset:64;      size:4; signed:0;
>          field:u32 row;  offset:68;      size:4; signed:0;
>          field:u8 cor_mask[0x20];        offset:72;      size:32;        signed:0;
>          field:u8 rank;  offset:104;     size:1; signed:0;
>          field:u8 bank_group;    offset:105;     size:1; signed:0;
>          field:u8 bank;  offset:106;     size:1; signed:0;

The above are the fields you need. If you want to see how they are
formatted in the output, you can add "--full" to the above command and
you'll see a "printf" like format.


Your output you showed in the previous email had:

> failed to get field: time
> <CANT FIND FIELD time>

There's no field "time" above.

> got field: id, len: 16
> got field: handle, len: 2
> got field: related_handle, len: 2
> failed to get field: hdr_flags
> <CANT FIND FIELD hdr_flags>

Same for "hdr_flags"

> got field: phys_addr, len: 8
> failed to get field: volatile
> <CANT FIND FIELD volatile>

And "volatile"

> failed to get field: desc
> <CANT FIND FIELD desc>

etc.

> got field: type, len: 1
> failed to get field: trans_type
> <CANT FIND FIELD trans_type>

etc.


> got field: channel, len: 1
> got field: rank, len: 1
> got field: nibble_mask, len: 4
> got field: bank_group, len: 1
> got field: bank, len: 1
> got field: row, len: 4
> got field: column, len: 2
> got field: cor_mask, len: 32
> failed to get field: valid_flags
> <CANT FIND FIELD valid_flags>

etc.


The field names are from the above format, not what you see in the output
of the event.

-- Steve



[Index of Archives]     [Linux USB Development]     [Linux USB Development]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux