On Fri, 31 Aug 2007 14:35:35 +0200 Guillaume Chazarain <[EMAIL PROTECTED]> wrote:
> TASKSTATS_CMD_ATTR_TGID used to return only the delay accounting stats, > not the basic and extended accounting. With this patch, > TASKSTATS_CMD_ATTR_TGID also aggregates the accounting info for all threads > of a > thread group. This makes TASKSTATS_CMD_ATTR_TGID usable in a similar > fashion to TASKSTATS_CMD_ATTR_PID, for commands like iotop -P > (http://guichaz.free.fr/misc/iotop.py). > > Here is the output of the testcase before the patch: > > ... > Documentation/accounting/dump-test.c | 314 > +++++++++++++++++++++++++++++++++++ Another C file in the Documentation directory. Sigh. At kernel summit I suggested that we should be putting these things in a place from where we can actually build and install them. People said there was no need to do that because kernel developers can now easily get new stuff into util-linux. I don't believe them. Wanna be a guinea pig? > +static void loop_reading(const char *filename) > +{ > + int fd = open(filename, O_RDONLY); > + char buffer[4096]; > + > + if (fd < 0) { > + perror(filename); > + return; > + } > + > + for (;;) { > + lseek(fd, 0, SEEK_SET); > + while (read(fd, buffer, sizeof(buffer)) > 0) ; newline here. Just because it's userspace doesn't mean that it needs to look crappy, despite all the code out there which disproves this ;) I think you just invented pread(). > + } > +} > + > > ... > > --- a/kernel/taskstats.c Fri Aug 31 01:42:23 2007 -0700 > +++ b/kernel/taskstats.c Fri Aug 31 13:36:29 2007 +0200 > @@ -168,6 +168,60 @@ static void send_cpu_listeners(struct sk > up_write(&listeners->sem); > } > > +/* > + * There are two types of taskstats fields when considering a thread group: > + * - those that can be aggregated from each thread in the group (like CPU > + * times), > + * - those that cannot be aggregated (like UID) or are identical (like > + * memory usage), so are taken from the group leader. > + * XXX_threadgroup() methods deal with the first type while XXX_add_tsk() > with > + * the second. > + */ > +static void fill_threadgroup(struct taskstats *stats, struct task_struct > *task) > +{ > + /* > + * Each accounting subsystem adds calls to its functions to initialize > + * relevant parts of struct taskstsats for a single tgid as follows: > + * > + * per-task-foo-fill_threadgroup(stats, task); > + */ > + > + stats->version = TASKSTATS_VERSION; > + > + /* fill in basic acct fields */ > + bacct_fill_threadgroup(stats, task); > + > + /* fill in extended acct fields */ > + xacct_fill_threadgroup(stats, task); > +} > + > +/* > + * Stats specific to each thread in the thread group. Stats of @task should > be > + * combined with those already present in @stats. add_tsk() works in > + * conjunction with fill_threadgroup(), taskstats fields should not be > touched > + * by both functions. > + */ It's odd to use kerneldoc-style markup in a non-kerneldoc comment. > @@ -232,32 +272,21 @@ static int fill_tgid(pid_t tgid, struct > else > memset(stats, 0, sizeof(*stats)); > > + leader = first->group_leader; > + get_task_struct(leader); > + fill_threadgroup(stats, leader); > + put_task_struct(leader); > + Are the get_task_struct/put_task_struct here actually needed? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
