Hey Timo,
Thanks again for all the work you do on DoveCot. I'd like to put
together a patch to avoid use of hardlinks on Mac OS X. It definitely
looks doable. (a couple of questions below...)
On Aug 8, 2006, at 6:16 PM, James Berry wrote:
On Aug 8, 2006, at 5:43 PM, James Berry wrote:
Hi Timo, (By the way, this seems to relate to a performance issue
on Mac OS X with HFS+).I think the problem may be more general than this particular case.
This fix speeds up some accesses, but there are still bottlenecks,
I believe. I have a feeling the performance issues will manifest in
any cases where hardlinks are used heavily.Can you tell me, Timo, in what other cases hard links are used
(file copy, seemingly being one) and whether there is any way to
turn them off or rework the code to avoid them?
In seaching the code for "link(", I find only four affected files/
cases. Here I look into possible implementations for a patch to
AVOID_HARDLINKS. Such a patch would dramatically improve performance
on Mac OS X with the HFS+ filesystem.
Timo, would you mind commenting on these to make sure my
understanding is correct? And for the last one, I need a suggestion
on how to proceed.
file-copy.c: [EASY]
Looks like it would be easy to take the already coded case for when try_hardlink is false.
file-dotlock.c: [EASY]
In dotlock_create, use try_create_lock_excl rather than try_create_lock_hardlink.
maildir-copy.c: [LOOKS EASY]
In maildir_copy(), take the fallback case using mail_storage_copy.maildir-save.c: [NEED HELP]
In maildir_file_move(), there seems to be no fallback case, and I'm unsure of the desired symantics, so I could use some suggestions
here: can we just fall back into something like the code in file-copy.c?
Thanks for your thoughts!
James