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authorJan Kara <jack@suse.cz>2019-11-06 11:48:57 +0100
committerJens Axboe <axboe@kernel.dk>2019-11-06 07:16:07 -0700
commitf8db383507d658c5a729b062c97710efda876cd4 (patch)
tree20879e9cbe8419ddb48704af106dd290a2f27071
parentfa53228721876515adabc7bc74368490bd97aa3b (diff)
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 <jmoyer@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/elevator.c9
1 files changed, 9 insertions, 0 deletions
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);