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).
Changelog since V4 (http://lkml.org/lkml/2007/9/15/171): - Revert gratuitous user interface change (returning exit_code >> 8 instead of exit_code). Thanks Oleg Nesterov. - Revert useless heavyweight locking (lock_task_sighand() in fill_tgid_exit). Thanks Oleg. - Correctly fill the TGID in taskstats_exit(). Thanks Oleg. Changelog since V3 (http://lkml.org/lkml/2007/8/31/121): - Removed userspace example, either it gets accepted in util-linux-ng or I'll maintain it elsewhere. - Added kerneldoc for fill_threadgroup() and add_tsk(). - Removed useless {get,put}_task_struct(leader) as spotted by Andrew Morton and Oleg Nesterov. - Use lock_task_sighand() instead of spin_lock_irqsave(&tsk->sighand->siglock) for consistency with the locking of task->signal->stats in fill_tgid(). - Removed useless check for a NULL taskstats in fill_tgid_exit(). Thanks Oleg. - Documented double accounting race seen by Oleg. - Rephrased the fill_tgid_exit() comment as per Oleg's recommendation. - Documented the special case for the AFORK ac_flag. - Use the exit status (code >> 8) instead of the exit code as documented in Documentation/accounting/taskstats-struct.txt. - Use signal->group_exit_code if set for stats->ac_exitcode on a TGID as suggested by Oleg. Changelog since V2 (http://lkml.org/lkml/2007/8/19/96): - Added a testcase - Added an indirection between the stats producer and consumer: add_task() & fill_threadgroup() - TGID stats are either summed from all the threads or taken from the leader Changelog since V1 (http://lkml.org/lkml/2007/8/2/185): - Update combined stats of exited threads in fill_tgid_exit() as suggested by Balbir Singh. - Very light cleanup of fill_tgid_exit() by the way. - bacct fields are also combined for all threads. - Instead of assuming memory stats are identical for all threads, we take the max of all threads. Signed-off-by: Guillaume Chazarain <[EMAIL PROTECTED]> Cc: Balbir Singh <[EMAIL PROTECTED]> Cc: Jay Lan <[EMAIL PROTECTED]> Cc: Jonathan Lim <[EMAIL PROTECTED]> Cc: Oleg Nesterov <[EMAIL PROTECTED]> --- include/linux/tsacct_kern.h | 12 ++- kernel/taskstats.c | 135 +++++++++++++++++++++------------- kernel/tsacct.c | 113 ++++++++++++++++------------ 3 files changed, 159 insertions(+), 101 deletions(-) diff -r 2908770b8fc2 include/linux/tsacct_kern.h --- a/include/linux/tsacct_kern.h Sun Sep 16 22:24:49 2007 -0700 +++ b/include/linux/tsacct_kern.h Tue Aug 28 20:35:27 2007 +0200 @@ -10,17 +10,23 @@ #include <linux/taskstats.h> #ifdef CONFIG_TASKSTATS -extern void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk); +void bacct_fill_threadgroup(struct taskstats *stats, struct task_struct *task); +void bacct_add_tsk(struct taskstats *stats, struct task_struct *task); #else -static inline void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk) +static inline void bacct_fill_threadgroup(struct taskstats *stats, struct task_struct *task) +{} +static inline void bacct_add_tsk(struct taskstats *stats, struct task_struct *task) {} #endif /* CONFIG_TASKSTATS */ #ifdef CONFIG_TASK_XACCT -extern void xacct_add_tsk(struct taskstats *stats, struct task_struct *p); +void xacct_fill_threadgroup(struct taskstats *stats, struct task_struct *task); +void xacct_add_tsk(struct taskstats *stats, struct task_struct *p); extern void acct_update_integrals(struct task_struct *tsk); extern void acct_clear_integrals(struct task_struct *tsk); #else +static inline void xacct_fill_threadgroup(struct taskstats *stats, struct task_struct *task) +{} static inline void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) {} static inline void acct_update_integrals(struct task_struct *tsk) diff -r 2908770b8fc2 kernel/taskstats.c --- a/kernel/taskstats.c Sun Sep 16 22:24:49 2007 -0700 +++ b/kernel/taskstats.c Mon Sep 17 22:55:04 2007 +0200 @@ -168,6 +168,68 @@ static void send_cpu_listeners(struct sk up_write(&listeners->sem); } +/** + * fill_threadgroup - initialize some common stats for the thread group + * @stats: the taskstats to write into + * @task: the thread representing the whole group + * + * 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); +} + +/** + * add_tsk - combine some thread specific stats in a taskstats + * @stats: the taskstats to write into + * @task: the thread to combine + * + * 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. + */ +static void add_tsk(struct taskstats *stats, struct task_struct *task) +{ + /* + * Each accounting subsystem adds calls to its functions to combine + * relevant parts of struct taskstsats for a single pid as follows: + * + * per-task-foo-add_tsk(stats, task); + */ + stats->nvcsw += task->nvcsw; + stats->nivcsw += task->nivcsw; + + /* fill in delay acct fields */ + delayacct_add_tsk(stats, task); + + /* fill in basic acct fields */ + bacct_add_tsk(stats, task); + + /* fill in extended acct fields */ + xacct_add_tsk(stats, task); +} + static int fill_pid(pid_t pid, struct task_struct *tsk, struct taskstats *stats) { @@ -185,23 +247,8 @@ static int fill_pid(pid_t pid, struct ta get_task_struct(tsk); memset(stats, 0, sizeof(*stats)); - /* - * Each accounting subsystem adds calls to its functions to - * fill in relevant parts of struct taskstsats as follows - * - * per-task-foo(stats, tsk); - */ - - delayacct_add_tsk(stats, tsk); - - /* fill in basic acct fields */ - stats->version = TASKSTATS_VERSION; - stats->nvcsw = tsk->nvcsw; - stats->nivcsw = tsk->nivcsw; - bacct_add_tsk(stats, tsk); - - /* fill in extended acct fields */ - xacct_add_tsk(stats, tsk); + fill_threadgroup(stats, tsk); + add_tsk(stats, tsk); /* Define err: label here if needed */ put_task_struct(tsk); @@ -232,32 +279,25 @@ static int fill_tgid(pid_t tgid, struct else memset(stats, 0, sizeof(*stats)); + fill_threadgroup(stats, first->group_leader); + tsk = first; - do { - if (tsk->exit_state) - continue; - /* - * Accounting subsystem can call its functions here to - * fill in relevant parts of struct taskstsats as follows - * - * per-task-foo(stats, tsk); - */ - delayacct_add_tsk(stats, tsk); - - stats->nvcsw += tsk->nvcsw; - stats->nivcsw += tsk->nivcsw; - } while_each_thread(first, tsk); + do + if (!tsk->exit_state) + /* + * This check is racy as a thread could exit just right + * now and have its statistics accounted twice. + */ + add_tsk(stats, tsk); + while_each_thread(first, tsk); + + if (first->signal->group_exit_code) + stats->ac_exitcode = first->signal->group_exit_code; unlock_task_sighand(first, &flags); rc = 0; out: rcu_read_unlock(); - - stats->version = TASKSTATS_VERSION; - /* - * Accounting subsytems can also add calls here to modify - * fields of taskstats. - */ return rc; } @@ -267,19 +307,14 @@ static void fill_tgid_exit(struct task_s unsigned long flags; spin_lock_irqsave(&tsk->sighand->siglock, flags); - if (!tsk->signal->stats) - goto ret; - - /* - * Each accounting subsystem calls its functions here to - * accumalate its per-task stats for tsk, into the per-tgid structure - * - * per-task-foo(tsk->signal->stats, tsk); - */ - delayacct_add_tsk(tsk->signal->stats, tsk); -ret: + + /* + * The fill_threadgroup() part of the statistics will be added by the + * stats requester, i.e. fill_tgid() + */ + add_tsk(tsk->signal->stats, tsk); + spin_unlock_irqrestore(&tsk->sighand->siglock, flags); - return; } static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd) @@ -508,7 +543,7 @@ void taskstats_exit(struct task_struct * if (!stats) goto err; - memcpy(stats, tsk->signal->stats, sizeof(*stats)); + fill_tgid(tsk->pid, tsk, stats); send: send_cpu_listeners(rep_skb, listeners); diff -r 2908770b8fc2 kernel/tsacct.c --- a/kernel/tsacct.c Sun Sep 16 22:24:49 2007 -0700 +++ b/kernel/tsacct.c Mon Sep 17 20:44:05 2007 +0200 @@ -22,50 +22,65 @@ #include <linux/acct.h> #include <linux/jiffies.h> -/* - * fill in basic accounting fields - */ -void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk) +static void fill_wall_times(struct taskstats *stats, struct task_struct *task) { struct timespec uptime, ts; s64 ac_etime; - BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN); - /* calculate task elapsed time in timespec */ do_posix_clock_monotonic_gettime(&uptime); - ts = timespec_sub(uptime, tsk->start_time); + ts = timespec_sub(uptime, task->start_time); /* rebase elapsed time to usec */ ac_etime = timespec_to_ns(&ts); do_div(ac_etime, NSEC_PER_USEC); - stats->ac_etime = ac_etime; - stats->ac_btime = get_seconds() - ts.tv_sec; - if (thread_group_leader(tsk)) { - stats->ac_exitcode = tsk->exit_code; - if (tsk->flags & PF_FORKNOEXEC) - stats->ac_flag |= AFORK; - } - if (tsk->flags & PF_SUPERPRIV) + stats->ac_etime = ac_etime; + stats->ac_btime = get_seconds() - ts.tv_sec; +} + +/* + * fill in basic accounting fields + */ + +void bacct_fill_threadgroup(struct taskstats *stats, struct task_struct *task) +{ + BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN); + + rcu_read_lock(); + stats->ac_ppid = pid_alive(task) ? + rcu_dereference(task->real_parent)->tgid : 0; + rcu_read_unlock(); + + fill_wall_times(stats, task); + + stats->ac_exitcode = task->exit_code; + stats->ac_nice = task_nice(task); + stats->ac_sched = task->policy; + stats->ac_uid = task->uid; + stats->ac_gid = task->gid; + stats->ac_pid = task->pid; + + strncpy(stats->ac_comm, task->comm, sizeof(stats->ac_comm)); +} + +void bacct_add_tsk(struct taskstats *stats, struct task_struct *task) +{ + if (task->flags & PF_SUPERPRIV) stats->ac_flag |= ASU; - if (tsk->flags & PF_DUMPCORE) + if (task->flags & PF_DUMPCORE) stats->ac_flag |= ACORE; - if (tsk->flags & PF_SIGNALED) + if (task->flags & PF_SIGNALED) stats->ac_flag |= AXSIG; - stats->ac_nice = task_nice(tsk); - stats->ac_sched = tsk->policy; - stats->ac_uid = tsk->uid; - stats->ac_gid = tsk->gid; - stats->ac_pid = tsk->pid; - rcu_read_lock(); - stats->ac_ppid = pid_alive(tsk) ? - rcu_dereference(tsk->real_parent)->tgid : 0; - rcu_read_unlock(); - stats->ac_utime = cputime_to_msecs(tsk->utime) * USEC_PER_MSEC; - stats->ac_stime = cputime_to_msecs(tsk->stime) * USEC_PER_MSEC; - stats->ac_minflt = tsk->min_flt; - stats->ac_majflt = tsk->maj_flt; + if (thread_group_leader(task) && (task->flags & PF_FORKNOEXEC)) + /* + * Threads are created by do_fork() and don't exec but not in + * the AFORK sense, as the latter involves fork(2). + */ + stats->ac_flag |= AFORK; - strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm)); + stats->ac_utime += cputime_to_msecs(task->utime) * USEC_PER_MSEC; + stats->ac_stime += cputime_to_msecs(task->stime) * USEC_PER_MSEC; + stats->ac_minflt += task->min_flt; + stats->ac_majflt += task->maj_flt; } @@ -76,32 +91,34 @@ void bacct_add_tsk(struct taskstats *sta /* * fill in extended accounting fields */ -void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) +void xacct_fill_threadgroup(struct taskstats *stats, struct task_struct *task) { struct mm_struct *mm; - /* convert pages-jiffies to Mbyte-usec */ - stats->coremem = jiffies_to_usecs(p->acct_rss_mem1) * PAGE_SIZE / MB; - stats->virtmem = jiffies_to_usecs(p->acct_vm_mem1) * PAGE_SIZE / MB; - mm = get_task_mm(p); + mm = get_task_mm(task); if (mm) { /* adjust to KB unit */ stats->hiwater_rss = mm->hiwater_rss * PAGE_SIZE / KB; - stats->hiwater_vm = mm->hiwater_vm * PAGE_SIZE / KB; + stats->hiwater_vm = mm->hiwater_vm * PAGE_SIZE / KB; mmput(mm); } - stats->read_char = p->rchar; - stats->write_char = p->wchar; - stats->read_syscalls = p->syscr; - stats->write_syscalls = p->syscw; +} + +void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) +{ + /* convert pages-jiffies to Mbyte-usec */ + stats->coremem += jiffies_to_usecs(p->acct_rss_mem1) * PAGE_SIZE / MB; + stats->virtmem += jiffies_to_usecs(p->acct_vm_mem1) * PAGE_SIZE / MB; + + stats->read_char += p->rchar; + stats->write_char += p->wchar; + stats->read_syscalls += p->syscr; + stats->write_syscalls += p->syscw; + #ifdef CONFIG_TASK_IO_ACCOUNTING - stats->read_bytes = p->ioac.read_bytes; - stats->write_bytes = p->ioac.write_bytes; - stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes; -#else - stats->read_bytes = 0; - stats->write_bytes = 0; - stats->cancelled_write_bytes = 0; + stats->read_bytes += p->ioac.read_bytes; + stats->write_bytes += p->ioac.write_bytes; + stats->cancelled_write_bytes += p->ioac.cancelled_write_bytes; #endif } #undef KB - 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/
