Date: Wed, 19 Oct 2011 18:35:04 +0400 From: Daniil Cherednik <dcherednik@masterhost.ru> To: <freebsd-questions@freebsd.org> Subject: sigprocmask system call Message-ID: <4E9EE018.205@masterhost.ru>
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Hello.
We are using FreeBSD 8.2 on hight load projects. When I was preparing
system for production I sow strange (as me think) behavior that can lead
to increased load on servers.
If I made truss on httpd (apache22) process, I saw too much syscalls
such us:
24822: sigprocmask(SIG_BLOCK,0x0,0x0) = 0 (0x0)
24822: sigprocmask(SIG_BLOCK,0x0,0x0) = 0 (0x0)
24822: sigprocmask(SIG_BLOCK,0x0,0x0) = 0 (0x0)
24822: sigprocmask(SIG_BLOCK,0x0,0x0) = 0 (0x0)
24822: sigprocmask(SIG_BLOCK,0x0,0x0) = 0 (0x0)
... too many line ...
and
24822:
sigprocmask(SIG_BLOCK,SIGHUP|SIGINT|SIGQUIT|SIGKILL|SIGPIPE|SIGALRM|SIGTERM|SIGURG|SIGSTOP|SIGTSTP|SIGCONT|SIGCHLD|SIGTTIN|SIGTTOU|SIGIO|SIGXCPU|SIGXFSZ|SIGVTALRM|SIGPROF|S
IGWINCH|SIGINFO|SIGUSR1|SIGUSR2,0x0) = 0 (0x0)
24822: sigprocmask(SIG_SETMASK,0x0,0x0) = 0 (0x0)
24822:
sigprocmask(SIG_BLOCK,SIGHUP|SIGINT|SIGQUIT|SIGKILL|SIGPIPE|SIGALRM|SIGTERM|SIGURG|SIGSTOP|SIGTSTP|SIGCONT|SIGCHLD|SIGTTIN|SIGTTOU|SIGIO|SIGXCPU|SIGXFSZ|SIGVTALRM|SIGPROF|S
IGWINCH|SIGINFO|SIGUSR1|SIGUSR2,0x0) = 0 (0x0)
24822: sigprocmask(SIG_SETMASK,0x0,0x0) = 0 (0x0)
24822:
sigprocmask(SIG_BLOCK,SIGHUP|SIGINT|SIGQUIT|SIGKILL|SIGPIPE|SIGALRM|SIGTERM|SIGURG|SIGSTOP|SIGTSTP|SIGCONT|SIGCHLD|SIGTTIN|SIGTTOU|SIGIO|SIGXCPU|SIGXFSZ|SIGVTALRM|SIGPROF|S
IGWINCH|SIGINFO|SIGUSR1|SIGUSR2,0x0) = 0 (0x0)
24822: sigprocmask(SIG_SETMASK,0x0,0x0) = 0 (0x0)
... too many line ...
but apache, and modules loaded from it do not call this directly.
I was trying to use DTRACE for getting information about syscalls, and I
got same result.
I wrote tiny sample
code:
#include<iostream>
main(){
fork();
}
I ran it on FreeBSD:
truss -f ./mytest 2>&1 | grep sigprocmask | wc -l
30
Is it normal to call so many syscalls ? For example, there is no
sigprocmask syscalls when I run it in Linux.
--
? ?????????,
Daniil Cherednik
.masterhost
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