From ac1171bd2c7a3a32dfbdd3c347919fee32b745a1 Mon Sep 17 00:00:00 2001 From: Jinlong Chen Date: Tue, 22 Nov 2022 22:21:23 +0800 Subject: [PATCH] elevator: update the document of elevator_switch We no longer support falling back to the old io scheduler if switching to the new one fails. Update the document to indicate that. Fixes: a1ce35fa4985 ("block: remove dead elevator code") Signed-off-by: Jinlong Chen Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/94250961689ba7d2e67a7d9e7995a11166fedb31.1669126766.git.nickyc975@zju.edu.cn Signed-off-by: Jens Axboe --- block/elevator.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/block/elevator.c b/block/elevator.c index a5bdc3b1e7e5b..01aa9f38f22ee 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -650,10 +650,10 @@ void elevator_init_mq(struct request_queue *q) } /* - * switch to new_e io scheduler. be careful not to introduce deadlocks - - * we don't free the old io scheduler, before we have allocated what we - * need for the new one. this way we have a chance of going back to the old - * one, if the new one fails init for some reason. + * Switch to new_e io scheduler. + * + * If switching fails, we are most likely running out of memory and not able + * to restore the old io scheduler, so leaving the io scheduler being none. */ int elevator_switch(struct request_queue *q, struct elevator_type *new_e) { -- 2.30.2