On 02/08/14 22:31, Howard Chu wrote:
Hallvard Breien Furuseth wrote:
So to explain my previous message a bit: A cacheflush() which flushes
a metapage and its datapages all in one chunk makes me nervous. If
that's necessary (rather than just flushing the meta at that point), I
imagine that just before the flush, it's possible for something to see
the metapage before its datapages.
Not possible. The cacheflush is atomic.
Fine, but it's the situation before the flush which worries
me, when the cache can be incoherent.
> Note that this is invalidating
an on-chip data cache which is typically only 32KB or so. It has nothing
to do with flushing the buffer cache. ("flush" is a misnomer, but that's
what the syscall is called.)
OK, but apparently it's still a cache which can include
data from both metapages and datapages.