Re: [patch] [possible race in ext2] Re: how to write get_block?

[Stephen C. Tweedie]

Hi,

On Thu, 14 Oct 1999 00:17:27 -0400, Raul Miller <[EMAIL PROTECTED]> said:

> Stephen C. Tweedie <[EMAIL PROTECTED]> wrote:
>> There is one major potential future problem with moving this to the
>> page cache. At some point I want to be able to extend the large (64G)
>> memory support on Intel to include the page cache in high memory.
>> The buffer cache would still live in low memory. If we do that, then
>> moving filesystem metadata out of permanently-mapped buffer memory
>> and into the page cache is going to complicate directory and indirect
>> operations significantly.

> Because of write ordering, I presume -- the dirty buffers you want most
> likely want to be able to write are (of the dirty buffers) the ones you
> most likely want to move out to large memory?

No, because accessing high memory pages from the kernel requires setting
up temporary VM indirection mappings, and all the filesystems assume
that they can access the data in their metadata buffers directly.

--Stephen