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better SMP support for kprobes
- From: Martin Hunt <hunt at redhat dot com>
- To: systemtap at sources dot redhat dot com
- Date: Wed, 02 Feb 2005 15:31:19 -0800
- Subject: better SMP support for kprobes
- Organization: Red Hat Inc.
Currently kprobe_handler grabs kprobe_lock and keeps it the entire time
the probe is executing. On SMP systems this could cause significant
performance degradation because only one cpu can be executing a kprobe;
all others will be blocked.
Has anyone looked at fixing this? Based on a quick read of the code, I
see the kprobe_lock is needed to protect access to the kprobe_table.
There are also a bunch of globals that could be implemented as per_cpu
data. Anyone want to volunteer to take a closer look?
Martin