Messages in this thread | | | Date | Tue, 24 Jan 2012 15:59:41 -0800 | From | Andrew Morton <> | Subject | Re: [patch 3/4] c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat |
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On Mon, 23 Jan 2012 18:20:39 +0400 Cyrill Gorcunov <gorcunov@openvz.org> wrote:
> We would like to have an ability to restore command line > arguments and envirion pointers so the task being restored > would print appropriate values in /proc/pid/cmdline and > /proc/pid/envirion. The exit_code is needed to restore > zombie tasks. >
Please update Documentation/filesystems/proc.txt.
> > --- linux-2.6.git.orig/fs/proc/array.c > +++ linux-2.6.git/fs/proc/array.c > @@ -464,7 +464,8 @@ static int do_task_stat(struct seq_file > > seq_printf(m, "%d (%s) %c %d %d %d %d %d %u %lu \ > %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \ > -%lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld %lu %lu %lu\n", > +%lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld %lu %lu %lu \ > +%lu %lu %lu %lu %d\n", > pid_nr_ns(pid, ns), > tcomm, > state, > @@ -514,7 +515,12 @@ static int do_task_stat(struct seq_file > cputime_to_clock_t(cgtime), > (mm && permitted) ? mm->start_data : 0, > (mm && permitted) ? mm->end_data : 0, > - (mm && permitted) ? mm->start_brk : 0); > + (mm && permitted) ? mm->start_brk : 0, > + (mm && permitted) ? mm->arg_start : 0, > + (mm && permitted) ? mm->arg_end : 0, > + (mm && permitted) ? mm->env_start : 0, > + (mm && permitted) ? mm->env_end : 0, > + task->exit_code); > if (mm) > mmput(mm); > return 0;
/proc/pid/stat is getting out of control. People are now sending patches because reading from this thing already takes too long.
The problem is that if you only want one field, you have to incur the cost of preparing all the fields. The magnitude of this problem increases exponentially over time!
I'm unsure what to do about it really. Perhaps add a new /proc/pid/mmstat for MM-specific things. We could put the above six fields in there, as long as we move quickly.
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