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Hello, Wenji.
Thank you for your suggestion.
I investigated RUSAGE_BOTH and got the following result: 1: _rusage_who_str is only used for sys_getrusage(and compat_sys_getrusage) in current tapset, and there is no other syscall which needs to call _rusage_who_str.
2: RUSAGE_BOTH is only used in kernel's internal function getrusage, but there is no syscall using this function with RUSAGE_BOTH.
So I think RUSAGE_BOTH is not necessary in tracing syscall, but it may be needed when tracing kernel function as getrusage.
It is good idea disable RUSAGE_BOTH only in sys_getrusage (and compat_sys_getrusage).
Regards
Zhaolei
----- Original Message ----- From: "Wenji Huang" <wenji.huang@oracle.com>
To: "Zhaolei" <zhaolei@cn.fujitsu.com>
Cc: <systemtap@sourceware.org>
Sent: Monday, September 10, 2007 11:44 AM
Subject: Re: [patch] For getrusage's argstr in tapset
Hi Zhaolei,
probe getrusage set probe point at the entry of the function. So the arguments may be any value.
So I think to keep the entry in _rusage_who_str, just give another mapping in case of some certain value.
Of course, if you can ensure that "who" only be RUSAGE_SELF/RUSAGE_CHILDREN when the syscall called. Just remove.
Thanks, Wenji
Zhaolei wrote:
Hi, everyone
In [tapset->probe getrusage], argstr's "who" argument is printed as "RUSAGE_BOTH" when its value is -2. But "RUSAGE_BOTH" is not used in getrusage syscall due to the following kernel source: asmlinkage long sys_getrusage(int who, struct rusage __user *ru) { if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN) return -EINVAL; return getrusage(current, who, ru); }
So i want to remove RUSAGE_BOTH from _rusage_who_str. Is there anyone knows why RUSAGE_BOTH is necessary, please tell me. and if no objection, I will commit it.
Signed-off-by: "Zhaolei" zhaolei@cn.fujitsu.com
--- aux_syscalls.stp.old 2007-09-06 11:51:14.000000000 +0900 +++ aux_syscalls.stp 2007-09-06 11:52:22.000000000 +0900 @@ -1661,7 +1661,6 @@ function _rlimit_resource_str(r) { function _rusage_who_str(w) { if(w==0) return "RUSAGE_SELF" if(w==-1) return "RUSAGE_CHILDREN" - if(w==-2) return "RUSAGE_BOTH" return sprintf("UNKNOWN VALUE: %d", w) }
Regards Zhaolei
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