On Tue, 26 May 2009 19:05:05 +0300 Boaz Harrosh <bharrosh@xxxxxxxxxxx> wrote: > On 05/26/2009 06:31 PM, FUJITA Tomonori wrote: > > > > Can we just fix some drivers not to do the DMA with the sense buffer in > > scsi_cmnd? IIRC, there are only five or six drivers that do such. > > This is not so. > All drivers that go through scsi_eh_prep_cmnd() will eventually DMA through > the regular read path. Including all the drivers that do nothing and let > scsi-ml do the REQUEST_SENSE > > Actually I have exact numbers, from the last time I did all that Hmm, we discussed this before, I think. scsi-ml uses scsi_eh_prep_cmnd only via scsi_send_eh_cmnd(). There are some users of scsi_send_eh_cmnd in scsi-ml but only scsi_request_sense does the DMA in the sense_buffer of scsi_cmnd. Only scsi_error_handler() uses scsi_request_sense() and scsi_send_eh_cmnd() works synchronously. So scsi-ml can easily avoid the the DMA in the sense_buffer of scsi_cmnd if we have one sense buffer per scsi_host. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
