Re: profiling connection overhead - Mailing list pgsql-hackers

From Robert Haas
Subject Re: profiling connection overhead
Date
Msg-id 55CFD67C-7D8E-44A0-970D-5635CBF6A2BE@gmail.com
Whole thread Raw
In response to Re: profiling connection overhead  (Andres Freund <andres@anarazel.de>)
Responses Re: profiling connection overhead
Re: profiling connection overhead
List pgsql-hackers
On Nov 24, 2010, at 4:05 PM, Andres Freund <andres@anarazel.de> wrote:
>>>
>>> Won't this just cause loads of additional pagefaults after fork() when
>>> those pages are used the first time and then a second time when first
>>> written to (to copy it)?
>>
>> Aren't we incurring those page faults anyway, for whatever memory
>> palloc is handing out?  The heap is no different from bss; we just
>> move the pointer with sbrk().
> Yes, but only once. Also scrubbing a page is faster than copying it... (and
> there were patches floating around to do that in advance, not sure if they got
> integrated into mainline linux)

I'm not following - can you elaborate?

...Robert

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