Re: VAXstation 4000/90 SCSI weirdness on 10 RC5
Johnny Billquist <[email protected]>
| Newsgroups | gmane.os.netbsd.ports.vax |
|---|---|
| Message-ID | <[email protected]> |
On 2024-03-23 14:25, Maciej W. Rozycki wrote:
> On Sat, 23 Mar 2024, Johnny Billquist wrote:
>
>> As for recovering - well. It's not like the system can just throw the disk
>> reads/writes away if you have a timeout. It's going to keep trying at it. The
>> only other option is to just crash.
>
> Well, the usual outcome is supposed to be EIO rather than a crash, though
> there are more complex scenarios too, e.g. when a page cannot be faulted
> in from storage.
True, if we're talking about a direct write from user level to disk,
sure. But when it hits the cache, then you won't notice until the cache
is flushed to disk. Where would the EIO go then, and what is the
expected outcome? Same with meta-data. And yes, paging is yet another
issue in there.
Reads are generally not going to cause as much buffer starvations I
think. Writes are the bigger problem in my head when just thinking about it.
But I might be missing something...?
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: [email protected] || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol