Re: (reiserfs) Re: More on Re: (reiserfs) Reiserfs and ext2fs (was Re: (reiserfs) Sum Benchmarks (these look typical?))

[ebiederm+eric@npwt.net (Eric W. Biederman)]

>>>>> "ST" == Stephen C Tweedie <sct@redhat.com> writes:
>> I just took the time and looked.  

>> And in buffer.c in get_hash_table if we are returning a locked buffer,
>> we always wait on that buffer until it is unlocked.  So to date we I
>> don't see us tempting fate, with writing to locked buffers.

ST> Whoops, yes, we do currently do copies for msync().  It's been too long
ST> since I was digging in that code...

Well I asked on Linux kernel and talked a little bit about this with Alan Cox.
He figures if we try and stop something like DMA half way through we
are in trouble but otherwise we should be o.k.

So for the next round I'll implement the cheap clear the dirty bit, on
the page tables trick.

Eric