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Re: memory_object_lock_request and memory_object_data_return fnord
From: |
Thomas Bushnell, BSG |
Subject: |
Re: memory_object_lock_request and memory_object_data_return fnord |
Date: |
27 Mar 2002 15:12:41 -0800 |
User-agent: |
Gnus/5.09 (Gnus v5.9.0) Emacs/21.1 |
Neal H Walfield <neal@cs.uml.edu> writes:
> > I think we should certainly use vm_copy for whole-page copies in
> > pager_memcpy because of the badly suboptimal behavior you've described.
>
> I have cooked up the attached implementation. I checked everything
> but a few border cases -- I need to write a few more tests. Perhaps,
> I will get to it this weekend. However, I am interested in some
> feedback.
One thing I think of looking at.
It may well be that for smaller number of pages, memcpy is actually
more efficient than vm_copy because of the constant overhead in the
latter function.
So I'd like to see some instrumentation of where that cutoff actually
is.
Until that's done, I have no problem with assuming any particular sane
value for the cutoff, but I think your function should have a tunable
parameter for it.
Thomas
- Re: GNU/Linux binary compatibility (Was: Re: memory_object_lock_request and memory_object_data_return fnord), (continued)
- Re: GNU/Linux binary compatibility (Was: Re: memory_object_lock_request and memory_object_data_return fnord), Oystein Viggen, 2002/03/25
- Re: GNU/Linux binary compatibility (Was: Re: memory_object_lock_request and memory_object_data_return fnord), Jeroen Dekkers, 2002/03/25
- Re: GNU/Linux binary compatibility (Was: Re: memory_object_lock_request and memory_object_data_return fnord), Farid Hajji, 2002/03/25
- Re: GNU/Linux binary compatibility (Was: Re: memory_object_lock_request and memory_object_data_return fnord), Jeroen Dekkers, 2002/03/25
- Re: GNU/Linux binary compatibility (Was: Re: memory_object_lock_request and memory_object_data_return fnord), Oystein Viggen, 2002/03/26
- Re: GNU/Linux binary compatibility (Was: Re: memory_object_lock_request and memory_object_data_return fnord), Jeroen Dekkers, 2002/03/26
- Re: memory_object_lock_request and memory_object_data_return fnord, Roland McGrath, 2002/03/25
- Re: memory_object_lock_request and memory_object_data_return fnord, Neal H Walfield, 2002/03/27
- Re: memory_object_lock_request and memory_object_data_return fnord,
Thomas Bushnell, BSG <=
- Re: memory_object_lock_request and memory_object_data_return fnord, Thomas Bushnell, BSG, 2002/03/14