On 11/26/23 11:59 PM, hch@xxxxxx wrote: > On Sat, Nov 25, 2023 at 05:38:28PM +0000, Michael Kelley wrote: >> Hyper-V guests and the Azure cloud have a particular interest here >> because Hyper-V guests uses SCSI as the standard interface to virtual >> disks. Azure cloud disks can be throttled to a limited number of IOPS, >> so the number of in-flights I/Os can be relatively high, and >> merging can be beneficial to staying within the throttle >> limits. Of the flip side, this problem hasn't generated complaints >> over the last 18 months that I'm aware of, though that may be more >> because commercial distros haven't been running 5.16 or later kernels >> until relatively recently. > > I think the more important thing is that if you care about reducing > the number of I/Os you probably should use an I/O scheduler. Reducing > the number of I/Os without an I/O scheduler isn't (and I'll argue > shouldn't) be a concern for the non I/O scheduler. Yep fully agree. -- Jens Axboe
