Subject: Re: fsync performance hit on 1.6.1
To: None <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-kern
Date: 07/09/2003 15:19:55
>> I ended up making it mmap MAP_ANON memory before forking into a
>> reader process and a writer process; they transferred ownership of
>> large blocks of memory by sending tiny tokens through a pipe.
> if we set the bits on the anon page(s) to mske it resident, will it
> ever be sent to the unified cache(buffer cache originally) or will
> there be any overhead at all associated with I/O to that page?

Well, I'm no UBC wizard.  Pre-UBC, it would never touch the buffer
cache because it was never read from nor written to a file.

Overhead?  The only overhead I'd expect would be that normally
associated with accessing memory: loading cache lines, simulating dirty
bits if the hardware doesn't provide them, that sort of thing.

/~\ The ASCII				der Mouse
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