Re: MMAP Buffers - Mailing list pgsql-hackers

From Tom Lane
Subject Re: MMAP Buffers
Date
Msg-id 12299.1302996945@sss.pgh.pa.us
Whole thread Raw
In response to Re: MMAP Buffers  (Radosław Smogura <rsmogura@softperience.eu>)
Responses Re: MMAP Buffers  (Radosław Smogura <rsmogura@softperience.eu>)
List pgsql-hackers
Radosław Smogura <rsmogura@softperience.eu> writes:
> No, no, no :) I wanted to do this, but from above reason I skipped it. I swap 
> VM pages, I do remap, in place where the shared buffer was I put mmaped page, 
> and in place where mmaped page was I put shared page (in certain cases, which 
> should be optimized by e. g. read for update, for initial read of page in 
> process I directly points to shared buffer), it can be imagined as I affects 
> TLB. This what I call "VM swap" is remapping, so I don't change pointers, I 
> change only where this pointers points in physical memory, preserving same 
> pointer in Virtual Memory.

... Huh?  Are you saying that you ask the kernel to map each individual
shared buffer separately?  I can't believe that's going to scale to
realistic applications.
        regards, tom lane


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