Re: [LSF/MM TOPIC][LSF/MM ATTEND] NAPI polling for block drivers
From: Hannes Reinecke <hare@suse.de>
Date: 2017-01-11 16:45:12
Also in:
linux-nvme, linux-scsi
On 01/11/2017 05:26 PM, Bart Van Assche wrote:
On Wed, 2017-01-11 at 17:22 +0100, Hannes Reinecke wrote:quoted
On 01/11/2017 05:12 PM, hch@infradead.org wrote:quoted
On Wed, Jan 11, 2017 at 04:08:31PM +0000, Bart Van Assche wrote:quoted
A typical Ethernet network adapter delays the generation of an interrupt after it has received a packet. A typical block device or HBA does not delay the generation of an interrupt that reports an I/O completion.NVMe allows for configurable interrupt coalescing, as do a few modern SCSI HBAs.Essentially every modern SCSI HBA does interrupt coalescing; otherwise the queuing interface won't work efficiently.Hello Hannes, The first e-mail in this e-mail thread referred to measurements against a block device for which interrupt coalescing was not enabled. I think that the measurements have to be repeated against a block device for which interrupt coalescing is enabled.
Guess what we'll be doing in the next few days ... Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N�rnberg GF: J. Hawn, J. Guild, F. Imend�rffer, HRB 16746 (AG N�rnberg)