8.2 + apache == a LOT of sigprocmask

[Kostik Belousov]

On Fri, Nov 18, 2011 at 12:00:57AM -0800, Doug Barton wrote:
> On 11/17/2011 02:57, Kostik Belousov wrote:
> >> > It's not catching there though:
> >> > 
> >> > Reading symbols from /libexec/ld-elf.so.1...done.
> >> > Loaded symbols for /libexec/ld-elf.so.1
> >> > 0x28183b2d in accept () at accept.S:3
> >> > 3	RSYSCALL(accept)
> >> > (gdb) c
> >> > Continuing.
> >> > no thread to satisfy query
> >> > 0x28183b2d in accept () at accept.S:3
> >> > 3	RSYSCALL(accept)
> >> > (gdb) info threads
> >> > Cannot get thread info: invalid key
> >> > (gdb)
> > Err, the other part of my message was that you shall set the breakpoint
> > on sigprocmask.
> 
> I'm sorry I'm not making myself clear. We are setting the breakpoint on
> sigprocmask. But, maybe I'm doing it wrong. Can you give precise
> instructions as to what you want me to do, from the beginning? Sorry to
> be so dense.
Find the pid of the process issuing excessive number of sigprocmask
calls. Do
$ gdb /usr/local/bin/httpd
(gdb) attach <pid>
(gdb) b _sigprocmask
(gdb) c
Bah ! Breakpoint fired.
(gdb) bt
(gdb) c
<... Repeat ... >

> 
> > I want to see a backtrace from the breakpoint hit.
> > Several times.
> 
> Me too. :)
> 
> Meanwhile, in response to one of the other questions, we are using
> mpm_prefork. Also, the particular problem we're seeing does not appear
> related to fork(). The pattern of sigprocmask() calls is different from
> the pattern you see with fork().
I am sure that your sigprocmask calls do not come from rtld, it is some
use of setjmp or sigsetjmp(1), most likely.

I am not aware of any significant users of setjmp or sigprocmask in
our system libraries.
> 
> 
> Doug
> 
> -- 
> 
> 		"We could put the whole Internet into a book."
> 		"Too practical."
> 
> 	Breadth of IT experience, and depth of knowledge in the DNS.
> 	Yours for the right price.  :)  http://SupersetSolutions.com/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 196 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20111118/5531e1e0/attachment.pgp