Why page fault handler behaved this way? Please help!

Kirill A. Shutemov kirill at shutemov.name
Wed Nov 5 09:58:29 EST 2014


On Wed, Nov 05, 2014 at 04:18:36PM +0800, 秦弋戈 wrote:
> Hello,
> 
> 
> Thank you very much for helping me. Before I see your reply, I enlarged
> my program and I saw more page faults in code segment. Now I know there
> is something called fault-around.
> 
> 
> I read the Chapter 16 of the ULK which introduces file access. I started
> to know a technique called read-ahead from this chapter. So what's the
> difference or relationship between fault-around and read-ahead? I think
> they are used in different areas (layers) but have the same idea. Am I
> right? 

readahead reads data from backing storage to page-cache, but it doesn't
map it to process' address space. fault-around maps pages which already in
page cache: via readahead or not.

-- 
 Kirill A. Shutemov



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