From: Eric Dumazet If CONFIG_TASK_IO_ACCOUNTING is defined, we update io accounting counters for each task. This patch permits reporting of values using the well known getrusage() syscall, filling ru_inblock and ru_oublock instead of null values. As TASK_IO_ACCOUNTING currently counts bytes counts, we approximate blocks count doing : nr_blocks = nr_bytes / 512 Example of use : ---------------------- After patch is applied, /usr/bin/time command can now give a good approximation of IO that the process had to do. $ /usr/bin/time grep tototo /usr/include/* Command exited with non-zero status 1 0.00user 0.02system 0:02.11elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k 24288inputs+0outputs (0major+259minor)pagefaults 0swaps $ /usr/bin/time dd if=/dev/zero of=/tmp/testfile count=1000 1000+0 enregistrements lus 1000+0 enregistrements écrits 512000 octets (512 kB) copiés, 0,00326601 seconde, 157 MB/s 0.00user 0.00system 0:00.00elapsed 80%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+3000outputs (0major+299minor)pagefaults 0swaps Signed-off-by: Eric Dumazet Cc: Oleg Nesterov Signed-off-by: Andrew Morton --- include/linux/sched.h | 1 include/linux/task_io_accounting_ops.h | 28 +++++++++++++++++++++++ kernel/exit.c | 9 +++++++ kernel/fork.c | 1 kernel/sys.c | 7 +++++ 5 files changed, 46 insertions(+) diff -puN include/linux/sched.h~getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible include/linux/sched.h --- a/include/linux/sched.h~getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible +++ a/include/linux/sched.h @@ -457,6 +457,7 @@ struct signal_struct { cputime_t utime, stime, cutime, cstime; unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw; unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt; + unsigned long inblock, oublock, cinblock, coublock; /* * Cumulative ns of scheduled CPU time for dead threads in the diff -puN include/linux/task_io_accounting_ops.h~getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible include/linux/task_io_accounting_ops.h --- a/include/linux/task_io_accounting_ops.h~getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible +++ a/include/linux/task_io_accounting_ops.h @@ -10,11 +10,29 @@ static inline void task_io_account_read( current->ioac.read_bytes += bytes; } +/* + * We approximate number of blocks, because we account bytes only. + * A 'block' is 512 bytes + */ +static inline unsigned long task_io_get_inblock(const struct task_struct *p) +{ + return p->ioac.read_bytes >> 9; +} + static inline void task_io_account_write(size_t bytes) { current->ioac.write_bytes += bytes; } +/* + * We approximate number of blocks, because we account bytes only. + * A 'block' is 512 bytes + */ +static inline unsigned long task_io_get_oublock(const struct task_struct *p) +{ + return p->ioac.write_bytes >> 9; +} + static inline void task_io_account_cancelled_write(size_t bytes) { current->ioac.cancelled_write_bytes += bytes; @@ -31,10 +49,20 @@ static inline void task_io_account_read( { } +static inline unsigned long task_io_get_inblock(const struct task_struct *p) +{ + return 0; +} + static inline void task_io_account_write(size_t bytes) { } +static inline unsigned long task_io_get_oublock(const struct task_struct *p) +{ + return 0; +} + static inline void task_io_account_cancelled_write(size_t bytes) { } diff -puN kernel/exit.c~getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible kernel/exit.c --- a/kernel/exit.c~getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible +++ a/kernel/exit.c @@ -42,6 +42,7 @@ #include /* for audit_free() */ #include #include +#include #include #include @@ -113,6 +114,8 @@ static void __exit_signal(struct task_st sig->nvcsw += tsk->nvcsw; sig->nivcsw += tsk->nivcsw; sig->sched_time += tsk->sched_time; + sig->inblock += task_io_get_inblock(tsk); + sig->oublock += task_io_get_oublock(tsk); sig = NULL; /* Marker for below. */ } @@ -1194,6 +1197,12 @@ static int wait_task_zombie(struct task_ p->nvcsw + sig->nvcsw + sig->cnvcsw; psig->cnivcsw += p->nivcsw + sig->nivcsw + sig->cnivcsw; + psig->cinblock += + task_io_get_inblock(p) + + sig->inblock + sig->cinblock; + psig->coublock += + task_io_get_oublock(p) + + sig->oublock + sig->coublock; spin_unlock_irq(&p->parent->sighand->siglock); } diff -puN kernel/fork.c~getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible kernel/fork.c --- a/kernel/fork.c~getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible +++ a/kernel/fork.c @@ -877,6 +877,7 @@ static inline int copy_signal(unsigned l sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero; sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0; sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0; + sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0; sig->sched_time = 0; INIT_LIST_HEAD(&sig->cpu_timers[0]); INIT_LIST_HEAD(&sig->cpu_timers[1]); diff -puN kernel/sys.c~getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible kernel/sys.c --- a/kernel/sys.c~getrusage-fill-ru_inblock-and-ru_oublock-fields-if-possible +++ a/kernel/sys.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include @@ -2021,6 +2022,8 @@ static void k_getrusage(struct task_stru r->ru_nivcsw = p->signal->cnivcsw; r->ru_minflt = p->signal->cmin_flt; r->ru_majflt = p->signal->cmaj_flt; + r->ru_inblock = p->signal->cinblock; + r->ru_oublock = p->signal->coublock; if (who == RUSAGE_CHILDREN) break; @@ -2032,6 +2035,8 @@ static void k_getrusage(struct task_stru r->ru_nivcsw += p->signal->nivcsw; r->ru_minflt += p->signal->min_flt; r->ru_majflt += p->signal->maj_flt; + r->ru_inblock += p->signal->inblock; + r->ru_oublock += p->signal->oublock; t = p; do { utime = cputime_add(utime, t->utime); @@ -2040,6 +2045,8 @@ static void k_getrusage(struct task_stru r->ru_nivcsw += t->nivcsw; r->ru_minflt += t->min_flt; r->ru_majflt += t->maj_flt; + r->ru_inblock += task_io_get_inblock(t); + r->ru_oublock += task_io_get_oublock(t); t = next_thread(t); } while (t != p); break; _