To continue the pointless (but maybe entertaining) argument :)
Jeff Garzik wrote:
jim owens wrote:
The filesystem mod-time might have nanoseconds in it, but
that does not mean 2 writes 100 nanoseconds apart will have
different mod-times.
Modern Linux filesystems absolutely do do metadata updates at that level
of granularity.
In filesystems it only counts if it makes it to disk.
10,000,000 write-to-disk metadata updates per second? I think not.
Even the top-of-the-line intel ssd can only do 3,300 writes per second.
Are you guaranteed district timestamps between writes? No, but then
again, metadata updates were never guaranteed between two writes either.
You might just be dirtying a mmap'd page, for example.
So this sounds like you at least agree with my original statement
that mod-time is not a 100% guarantee that no write occurred after
you read a particular block of a file. Regardless of the fact we
disagree about how accurate filesystems record times.
jim
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
