On Mon, Aug 17, 2015 at 11:45:53PM +0900, Akinobu Mita wrote: > From mm/page-writeback.c: > > /* > * bdi_min_ratio keeps the sum of the minimum dirty shares of all > * registered backing devices, which, for obvious reasons, can not > * exceed 100%. > */ > static unsigned int bdi_min_ratio; > > But when a backing device is unregistered, the BDI's min_ratio is not > subtracted from bdi_min_ratio. So the second attempt to set min_ratio > in the following commands will fail. > > # modprobe null_blk > # echo 50 > /sys/block/nullb0/bdi/min_ratio > # modprobe -r null_blk > # modprobe null_blk > # echo 50 > /sys/block/nullb0/bdi/min_ratio > > Signed-off-by: Akinobu Mita <[email protected]> > Cc: Tejun Heo <[email protected]> > Cc: Jens Axboe <[email protected]>
Acked-by: Tejun Heo <[email protected]> We probably want to cc stable too. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
