Hi! 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 Thanks! Nick-- 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 http://vger.kernel.org/majordomo-info.html
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