From f9ed31214e2ac43cd38d1e517e774050b613b8da Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 22 Apr 2025 13:22:05 -0700 Subject: [PATCH] dm-verity: use softirq context only when !need_resched() Further limit verification in softirq (a.k.a. BH) context to cases where rescheduling of the interrupted task is not pending. This helps prevent the CPU from spending too long in softirq context. Note that handle_softirqs() in kernel/softirq.c already stops running softirqs in this same case. However, that check is too coarse-grained, since many I/O requests can be processed in a single BLOCK_SOFTIRQ. Signed-off-by: Eric Biggers Signed-off-by: Mikulas Patocka --- drivers/md/dm-verity-target.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 3c427f18a04b..4de2c226ac9d 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -682,7 +682,8 @@ static void verity_bh_work(struct work_struct *w) static inline bool verity_use_bh(unsigned int bytes, unsigned short ioprio) { return ioprio <= IOPRIO_CLASS_IDLE && - bytes <= READ_ONCE(dm_verity_use_bh_bytes[ioprio]); + bytes <= READ_ONCE(dm_verity_use_bh_bytes[ioprio]) && + !need_resched(); } static void verity_end_io(struct bio *bio) -- 2.50.1