Dear Mr.Axboe, The latest kernel sr_module still uses single mutex,it will serialise all sr ioctls. Otto Meta had mentioned this on Jan 1st, 2013 . Some record tools such as growisofs use SG_IO to write data to disc, so if there are multiple cdroms being recorded at the same time，it will be very slowly. I saw sd_module before,it had removed BKL and made "openers" atomic_t in scsi_disk. Shall we do the same thing to sr_module? That is, to remove sr_mutex and make "use_count" atomic_t in cdrom_device_info. Yours Sincerely, -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
