Dear all: 2010/12/10 loody <milo...@gmail.com>: > hi: > > 2010/12/10 pradeep singh <pradeep.raut...@gmail.com>: >> >> On Dec 10, 2010 6:39 AM, "loody" <milo...@gmail.com> wrote: >>> >>> hi Muyadi: >>> 2010/12/10 Mulyadi Santosa <mulyadi.sant...@gmail.com>: >>> > Hi... >>> > >>> > On Thu, Dec 9, 2010 at 21:56, loody <milo...@gmail.com> wrote: >>> >> Deal all: >>> >> I have some questions about times in #include <sys/times.h>. >>> >> As far as I know, times will "get process and waited-for child process >>> >> times". >>> >> so if the child is not finish or dead, this function will cause the >>> >> deadlock, right? >>> > >>> > From "man 2 times" >>> > " In Linux kernel versions before 2.6.9, if the disposition of SIGCHLD >>> > is >>> > set to SIG_IGN then the times of terminated children are >>> > automatically >>> > included in the tms_cstime and tms_cutime fields, although >>> > POSIX.1-2001 >>> > says that this should only happen if the calling process wait()s >>> > on its >>> > children. This non-conformance is rectified in Linux 2.6.9 and >>> > later" >>> > >>> > So, indirectly, I think the time accumulation happens when the wait() >>> > function returns...which is...I guess polling or regularly checking >>> > (select() maybe?) the signal from child. >>> > >>> thanks for ur help. >>> But I man nothing about times. >>> >>> $ man 2 times >>> No manual entry for times in section 2 >>> $ >>> >>> Should I update any packages? >> >> Yes you should try installing dev , posix and posix-dev manpages. > should I use any one of below apt-get packages? > sudo apt-get install dev > sudo apt-get install posix > sudo apt-get install posix-dev > appreciate your help, > miloody
after tracing the kernel source code, I found "times" seems a system call and it will call thread_group_cputime for collectiing all the time duration of its threads. It should return fast, since it just repeatedly call next_thread and add the utime and stime. if my observation is correct, this function will not consume much cpu time, right? appreciate your help, miloody -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecar...@nl.linux.org Please read the FAQ at http://kernelnewbies.org/FAQ
