From f8db383507d658c5a729b062c97710efda876cd4 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 6 Nov 2019 11:48:57 +0100 Subject: block: Warn if elevator= parameter is used With transition to blk-mq, the elevator= kernel argument was removed as it makes less and less sense with the current variety of devices. Since this may surprise some users and there are advices on the Internet that still suggest to use it, let's at least warn if the parameter is used. Reviewed-by: Jeff Moyer Signed-off-by: Jan Kara Signed-off-by: Jens Axboe --- block/elevator.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/block/elevator.c b/block/elevator.c index 5437059c9261..0b1db9afb586 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -831,3 +831,12 @@ struct request *elv_rb_latter_request(struct request_queue *q, return NULL; } EXPORT_SYMBOL(elv_rb_latter_request); + +static int __init elevator_setup(char *str) +{ + pr_warn("Kernel parameter elevator= does not have any effect anymore.\n" + "Please use sysfs to set IO scheduler for individual devices.\n"); + return 1; +} + +__setup("elevator=", elevator_setup); -- cgit v1.2.3