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[Bug testsuite/11514] nd_syscall.exp takes more than 10 times longer than syscall.exp testcase
- From: "mjw at redhat dot com" <sourceware-bugzilla at sourceware dot org>
- To: systemtap at sources dot redhat dot com
- Date: 22 Apr 2010 09:45:05 -0000
- Subject: [Bug testsuite/11514] nd_syscall.exp takes more than 10 times longer than syscall.exp testcase
- References: <20100419113044.11514.mjw@redhat.com>
- Reply-to: sourceware-bugzilla at sourceware dot org
------- Additional Comments From ananth at in dot ibm dot com 2010-04-22 03:46 -------
Subject: Re: nd_syscall.exp takes more than 10 times
longer than syscall.exp testcase
On Wed, Apr 21, 2010 at 07:05:39PM -0000, jistone at redhat dot com wrote:
>
> But on PPC64, it's a little more complicated to deal with function descriptors.
> In some cases the returned address is actually a pointer to the real address,
> and in other cases it tries to search again with a '.' added to the name. We
> need to deal with this too if we're bypassing kprobe_lookup_name().
Right, on PPC64, the symbol table address entry foo, for a function foo()
is a data address while .foo is the actual text address. In the past,
the System.map would contain both foo and .foo; RHEL5 on, the .foo
entries have been omitted from there.
If possible, I'd suggest that you don't bypass kprobe_lookup_name() for
debuginfoless probes, since it handles more cases like symbol clashes
between modules and such; let the kernel resolve the addresses for us.
------- Additional Comments From mjw at redhat dot com 2010-04-22 09:45 -------
Lets just disable to optimization on ppc64, which seems to be the only
architecture with different function descriptors.
commit 2cbd952ba29e03641ddfa717a2996b93594a5106
Author: Mark Wielaard <mjw@redhat.com>
Date: Thu Apr 22 11:42:27 2010 +0200
PR11514 Disable kallsyms_on_each_symbol optimization on ppc64.
* runtime/autoconf-kallsyms-on-each-symbol.c: #error on #ifdef CONFIG_PPC64.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|REOPENED |RESOLVED
Resolution| |FIXED
http://sourceware.org/bugzilla/show_bug.cgi?id=11514
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