On Thu, Jul 25 2013, Nicholas A. Bellinger wrote: > On Thu, 2013-07-25 at 12:16 +0200, Alexander Gordeev wrote: > > On Mon, Jul 22, 2013 at 02:10:36PM -0700, Nicholas A. Bellinger wrote: > > > Np. FYI, you'll want to use the latest commit e7827b351 HEAD from > > > target-pending/scsi-mq, which now has functioning scsi-generic support. > > > > Survives a boot, a kernel build and the build's result :) > > Great. Thanks for the feedback Alexander! > > So the next step on my end is to enable -mq for ahci, and verify initial > correctness using QEMU/KVM hardware emulation. > > Btw, I've been looking at enabling the SHT->cmd_size for struct > ata_queued_cmd descriptor pre-allocation, but AFAICT these descriptors > are already all pre-allocated by libata and obtained via ata_qc_new() -> > __ata_qc_from_tag() during ata_scsi_queuecmd(). Might still not be a bad idea to do it: - Cleans up a driver, getting rid of the need to alloc, maintain, and free those structures. - Should be some cache locality benefits to having it all sequential. > So that said, with the struct request + struct scsi_cmnd pre-allocations > already provided by blk-mq -> scsi-mq code, all memory allocations > should have already been eliminated from I/O fast path. Nice! -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
