mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-10-28 23:24:50 +00:00
Code Issues Releases Wiki Activity

io_uring: handle signals for IO threads like a normal thread

Browse source 
We go through various hoops to disallow signals for the IO threads, but
there's really no reason why we cannot just allow them. The IO threads
never return to userspace like a normal thread, and hence don't go through
normal signal processing. Instead, just check for a pending signal as part
of the work loop, and call get_signal() to handle it for us if anything
is pending.

With that, we can support receiving signals, including special ones like
SIGSTOP.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2021-03-25 18:16:06 -06:00
parent 10442994ba
commit dbe1bdbb39
2 changed files with 20 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
fs/io-wq.c
View file

@ -16,7 +16,6 @@
#include <linux/rculist_nulls.h>
#include <linux/cpu.h>
#include <linux/tracehook.h>
#include <linux/freezer.h>
#include "../kernel/sched/sched.h"
#include "io-wq.h"
@ -503,10 +502,15 @@ static int io_wqe_worker(void *data)
if (io_flush_signals())
continue;
ret = schedule_timeout(WORKER_IDLE_TIMEOUT);
if (try_to_freeze() || ret)
continue;
if (fatal_signal_pending(current))
if (signal_pending(current)) {
struct ksignal ksig;
if (!get_signal(&ksig))
continue;
break;
}
if (ret)
continue;
/* timed out, exit unless we're the fixed worker */
if (test_bit(IO_WQ_BIT_EXIT, &wq->state) ||
!(worker->flags & IO_WORKER_F_FIXED))
@ -714,9 +718,13 @@ static int io_wq_manager(void *data)
set_current_state(TASK_INTERRUPTIBLE);
io_wq_check_workers(wq);
schedule_timeout(HZ);
try_to_freeze();
if (fatal_signal_pending(current))
if (signal_pending(current)) {
struct ksignal ksig;
if (!get_signal(&ksig))
continue;
set_bit(IO_WQ_BIT_EXIT, &wq->state);
}
} while (!test_bit(IO_WQ_BIT_EXIT, &wq->state));
io_wq_check_workers(wq);

9
fs/io_uring.c
View file

@ -78,7 +78,6 @@
#include <linux/task_work.h>
#include <linux/pagemap.h>
#include <linux/io_uring.h>
#include <linux/freezer.h>
#define CREATE_TRACE_POINTS
#include <trace/events/io_uring.h>
@ -6765,8 +6764,13 @@ static int io_sq_thread(void *data)
timeout = jiffies + sqd->sq_thread_idle;
continue;
}
if (fatal_signal_pending(current))
if (signal_pending(current)) {
struct ksignal ksig;
if (!get_signal(&ksig))
continue;
break;
}
sqt_spin = false;
cap_entries = !list_is_singular(&sqd->ctx_list);
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
@ -6809,7 +6813,6 @@ static int io_sq_thread(void *data)
mutex_unlock(&sqd->lock);
schedule();
try_to_freeze();
mutex_lock(&sqd->lock);
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
io_ring_clear_wakeup_flag(ctx);