diff options
| author | Jens Axboe <axboe@kernel.dk> | 2025-10-21 07:16:08 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-10-22 10:51:20 -0600 |
| commit | 8ac9b0d33e5c0a995338ee5f25fe1b6ff7d97f65 (patch) | |
| tree | 5313eb47ba5848ad203ad59307c05a499d075a7f /io_uring/sqpoll.c | |
| parent | 4ec703ec0c384a2199808c4eb2e9037236285a8d (diff) | |
io_uring/sqpoll: switch away from getrusage() for CPU accounting
getrusage() does a lot more than what the SQPOLL accounting needs, the
latter only cares about (and uses) the stime. Rather than do a full
RUSAGE_SELF summation, just query the used stime instead.
Cc: stable@vger.kernel.org
Fixes: 3fcb9d17206e ("io_uring/sqpoll: statistics of the true utilization of sq threads")
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/sqpoll.c')
| -rw-r--r-- | io_uring/sqpoll.c | 32 |
1 files changed, 18 insertions, 14 deletions
diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c index a3f11349ce06..2b816fdb9866 100644 --- a/io_uring/sqpoll.c +++ b/io_uring/sqpoll.c @@ -11,6 +11,7 @@ #include <linux/audit.h> #include <linux/security.h> #include <linux/cpuset.h> +#include <linux/sched/cputime.h> #include <linux/io_uring.h> #include <uapi/linux/io_uring.h> @@ -169,6 +170,20 @@ static inline bool io_sqd_events_pending(struct io_sq_data *sqd) return READ_ONCE(sqd->state); } +u64 io_sq_cpu_usec(struct task_struct *tsk) +{ + u64 utime, stime; + + task_cputime_adjusted(tsk, &utime, &stime); + do_div(stime, 1000); + return stime; +} + +static void io_sq_update_worktime(struct io_sq_data *sqd, u64 usec) +{ + sqd->work_time += io_sq_cpu_usec(current) - usec; +} + static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries) { unsigned int to_submit; @@ -255,26 +270,15 @@ static bool io_sq_tw_pending(struct llist_node *retry_list) return retry_list || !llist_empty(&tctx->task_list); } -static void io_sq_update_worktime(struct io_sq_data *sqd, struct rusage *start) -{ - struct rusage end; - - getrusage(current, RUSAGE_SELF, &end); - end.ru_stime.tv_sec -= start->ru_stime.tv_sec; - end.ru_stime.tv_usec -= start->ru_stime.tv_usec; - - sqd->work_time += end.ru_stime.tv_usec + end.ru_stime.tv_sec * 1000000; -} - static int io_sq_thread(void *data) { struct llist_node *retry_list = NULL; struct io_sq_data *sqd = data; struct io_ring_ctx *ctx; - struct rusage start; unsigned long timeout = 0; char buf[TASK_COMM_LEN] = {}; DEFINE_WAIT(wait); + u64 start; /* offload context creation failed, just exit */ if (!current->io_uring) { @@ -317,7 +321,7 @@ static int io_sq_thread(void *data) } cap_entries = !list_is_singular(&sqd->ctx_list); - getrusage(current, RUSAGE_SELF, &start); + start = io_sq_cpu_usec(current); list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { int ret = __io_sq_thread(ctx, cap_entries); @@ -333,7 +337,7 @@ static int io_sq_thread(void *data) if (sqt_spin || !time_after(jiffies, timeout)) { if (sqt_spin) { - io_sq_update_worktime(sqd, &start); + io_sq_update_worktime(sqd, start); timeout = jiffies + sqd->sq_thread_idle; } if (unlikely(need_resched())) { |