Looks like I was way off. I compared between sysctl & dkctl output between amd64 & macppc port before I replied to the list & didn't look at the source code.
On 01/23/18 22:06, Paul Goyette wrote: > That's not quite 100% true, as I recall. As I discovered while making > the various strategies into modules .... > > The ccd, cgd, fss, dkwedge, raidframe, and flash drivers explicitly > request the "fcfs" bufq strategy (in the call to bufq_alloc()), as does > the nvme driver (via its call to ldattach()). The gpib/xxx ct, md, and > rd drivers also request "fcfs". > > The scsi cd(4) driver explicitly requests the "disksort" strategy. > > The ata/wd, ld, and vnd drivers request BUFQ_SORT_RAWBLOCK > > The scsi sd driver as well as the ata/wd driver and all other callers of > ldattach() use the default BUFQ_DISK_DEFAULT_STRAT which allows the > system to pick one based on the priority (and the SORT flag) - see > kern/subr_bufq.c:bufq_alloc() > > The priority values (higher number preferred) are: > > fcfs 10 > disksort 20 > readprio 30 > priocscan 40 > > The above is not a completely exhaustive list - check all the callers of > bufq_alloc() for more details, especially WRT machine- and architecture- > specific devices. Sevan
