perf probe resolving different symbol?

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



I’m having some issues with symbol resolution; namely, perf probe seems to think it’s happily attaching to the symbol (nfs_readpages:362) I’m looking for and yet it shows up as a different symbol (nfs_symlink_filter+36).

I’d love some help!

# uname -a

Linux a-b06-u47 3.10.0-693.2.2.el7.x86_64 #1 SMP Sat Sep 9 03:55:24 EDT 2017 x86_64 x86_64 x86_64 GNU/Linux

# perf probe -v -m /usr/lib/debug/lib/modules/3.10.0-693.2.2.el7.x86_64/kernel/fs/nfs/nfs.ko.debug -a 'nfs_readpages:46 pgm->pg_bytes_written'
probe-definition(0): nfs_readpages:46 pgm->pg_bytes_written
symbol:nfs_readpages file:(null) line:46 offset:0 return:0 lazy:(null)
parsing arg: pgm->pg_bytes_written into pgm, pg_bytes_written(1)
1 arguments
No kprobe blacklist support, ignored
Open Debuginfo file: /usr/lib/debug/usr/lib/modules/3.10.0-693.2.2.el7.x86_64/kernel/fs/nfs/nfs.ko.debug
Try to find probe point from debuginfo.
Matched function: nfs_readpages [143625]
Probe point found: nfs_readpages+362
Searching 'pgm' variable in context.
Converting variable pgm into trace event.
converting pg_bytes_written in pgm
pg_bytes_written type is long unsigned int.
Found 1 probe_trace_events.
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: p:probe/nfs_readpages /usr/lib/debug/usr/lib/modules/3.10.0-693.2.2.el7.x86_64/kernel/fs/nfs/nfs.ko.debug:nfs_symlink_filler+36 pg_bytes_written=+16(%ax):u64
Added new event:
  probe:nfs_readpages  (on nfs_readpages:46 in /usr/lib/debug/usr/lib/modules/3.10.0-693.2.2.el7.x86_64/kernel/fs/nfs/nfs.ko.debug with pg_bytes_written=pgm->pg_bytes_written)

[root@a-b06-u47 tracing]# cat kprobe_events 
p:probe/nfs_readpages /usr/lib/debug/usr/lib/modules/3.10.0-693.2.2.el7.x86_64/kernel/fs/nfs/nfs.ko.debug:nfs_symlink_filler+36 pg_bytes_written=+16(%ax):u64


To unsubscribe from this list: send the line "unsubscribe linux-trace-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at

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

  Powered by Linux