https://bugzilla.kernel.org/show_bug.cgi?id=12752 Adam Radford <aradford@xxxxxxxxx> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |aradford@xxxxxxxxx --- Comment #2 from Adam Radford <aradford@xxxxxxxxx> 2011-06-10 23:05:02 --- devsk, I'm sorry about you not getting a response from the previous megaraid_sas developer. He was probably not watching bugzilla.kernel.org. There is nothing in the driver that will 'throttle' the I/O on your PERC5 controller. The software raid code sets various read-ahead values in the block layer request_queues it sets up: # grep -i "ra_pages" * raid0.c: * If an individual device has an ra_pages greater than the raid0.c: if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) raid0.c: mddev->queue->backing_dev_info.ra_pages = 2* stripe; raid10.c: if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) raid10.c: mddev->queue->backing_dev_info.ra_pages = 2* stripe; raid5.c: if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) raid5.c: mddev->queue->backing_dev_info.ra_pages = 2 * stripe; raid5.c: if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe) raid5.c: conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe; Can you try setting some OS read-ahead values (on top of the controller doing read-ahead) for the scsi device attached to your PERC5 controller and re-running your tests? i.e.: /sbin/blockdev --getra /dev/sda (See what you have set currently) /sbin/blockdev --setra 8192 /dev/sda (Set read ahead for sda to 8192 sectors) /sbin/blockdev --setra 16834 /dev/sda (Set read ahead for sda to 16384 sectors) This may cause more I/O to be issued to the card from the OS and may improve your bonnie++ results. -Adam -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- 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
