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

["Stephen C. Tweedie" <sct@redhat.com>]

Hi,

On 01 Jul 1998 08:11:46 -0500, ebiederm+eric@npwt.net (Eric
W. Biederman) said:

ST> Read the source code!  We already do this.  If one process or thread
ST> msync()s a mapped file, its dirty pages get written to disk,
ST> independently of any other processes on the same or other CPUs which
ST> may still have the pages mapped and may still be writing to them.  We
ST> don't unmap pages for write; we just mark them non-dirty around all
ST> ptes.

> 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.

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

--Stephen