On 6/5/20 4:54 PM, Andres Freund wrote: > Hi, > > On 2020-06-05 16:49:24 -0600, Jens Axboe wrote: >> Yes that's expected, if we have to fallback to ->readpage(), then it'll >> go to a worker. read-ahead is what drives the async nature of it, as we >> issue the range (plus more, depending on RA window) as read-ahead for >> the normal read, then wait for it. > > But I assume async would still work for files with POSIX_FADV_RANDOM > set, or not? Assuming the system wide setting isn't zero, of course. Yes it'll work if FADV_RANDOM is set. But just not if read-ahead is totally disabled. I guess we could make that work too, though not sure that it's super important. -- Jens Axboe
