This is the mail archive of the
systemtap@sourceware.org
mailing list for the systemtap project.
[Bug kprobes/2666] List active probes
- From: "jamesd dot wi at gmail dot com" <sourceware-bugzilla at sourceware dot org>
- To: systemtap at sources dot redhat dot com
- Date: 16 Jan 2007 15:55:37 -0000
- Subject: [Bug kprobes/2666] List active probes
- References: <20060516165627.2666.jkenisto@us.ibm.com>
- Reply-to: sourceware-bugzilla at sourceware dot org
------- Additional Comments From jamesd dot wi at gmail dot com 2007-01-16 15:55 -------
Subject: Re: List active probes
On 16 Jan 2007 13:09:20 -0000, srinivasa at in dot ibm dot com
<sourceware-bugzilla@sourceware.org> wrote:
>
> ------- Additional Comments From srinivasa at in dot ibm dot com 2007-01-16 13:09 -------
> (In reply to comment #2)
> > any idea how the system will respond when there are 40,000 active
> > probes or more?
> >
> > James Dickens
> > uadmin.blogspot.com
> >
> >
> Eventhough I haven't tested the patch for 40,000 active probes, size of
> /proc/kprobes/list file depends on available memory and maximum size of the
> proc file.
>
i was thinking about the time spent in
+ preempt_disable();
+ hlist_for_each_entry_rcu(p, node, head, hlist) {
+ sym = kallsyms_lookup((unsigned long)p->addr, &size,
+ &offset, &modname, namebuf);
+ if (p->pre_handler == aggr_pre_handler) {
+ list_for_each_entry_rcu(kp, &p->list, list)
+ report_probe(pi, kp, sym, offset, modname);
+ } else
+ report_probe(pi, p, sym, offset, modname);
+ }
+ preempt_enable();
with preemption disabled... it could a second or more, if many probes
are enabled, it could have a negative effect on a production server.
James
> --
>
>
> http://sourceware.org/bugzilla/show_bug.cgi?id=2666
>
> ------- You are receiving this mail because: -------
> You are the assignee for the bug, or are watching the assignee.
>
--
http://sourceware.org/bugzilla/show_bug.cgi?id=2666
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.