8.2 + apache == a LOT of sigprocmask

Doug Barton dougb at FreeBSD.org
Mon Nov 14 20:51:36 UTC 2011


On 11/14/2011 12:31, Doug Barton wrote:
> Trying to track down a load problem we're seeing on 8.2-RELEASE-p4 i386
> in a busy web hosting environment I came across the following post:
> 
> http://lists.freebsd.org/pipermail/freebsd-questions/2011-October/234520.html
> 
> That basically describes what we're seeing as well, including the
> "doesn't happen on Linux" part.
> 
> Does anyone have any ideas about this?
> 
> With incredibly similar stuff running on 7.x we didn't see this problem,
> so it seems to be something new in 8.

Just took a closer look at our ktrace, and actually our pattern is
slightly different than the one in that post. In ours the second option
is null, but the third is set:

74195 httpd    0.000017 RET   sigprocmask 0
74195 httpd    0.000013 CALL  sigprocmask(SIG_BLOCK,0,0xbfbf89d4)
74195 httpd    0.000009 RET   sigprocmask 0
74195 httpd    0.000013 CALL  sigprocmask(SIG_BLOCK,0,0xbfbf89d4)
74195 httpd    0.000009 RET   sigprocmask 0
74195 httpd    0.000012 CALL  sigprocmask(SIG_BLOCK,0,0xbfbf89d4)

But repeated hundreds of times in a row.

-- 

		"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/



More information about the freebsd-stable mailing list