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To: "Cabaniols, Sebastien" <Sebastien.Cabaniols@Compaq.com>
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Subject: Re: pagecoloring: kernel 2.2 mm question: what is happening during fork ?
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From: Momchil Velikov <velco@fadata.bg>
Date: 29 Jan 2002 16:43:19 +0200
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>>>>> "Cabaniols" == Cabaniols, Sebastien <Sebastien.Cabaniols@Compaq.com> writes:

Cabaniols> When I do a fork, which part of the kernel is allocating the memory for
Cabaniols> the childs, where and when the memory copy takes place ?

mm/memory.c:copy_page_range()

It copies page tables and marks the ptes copy-on-write.

Cabaniols> I know that
Cabaniols> linux is doing copy on write but I don't know which part of the kernel
Cabaniols> is really doing the page allocation when the copy on write understands
Cabaniols> that the process really wants to write now. Then the second question is
Cabaniols> how is the memory copy done ?

mm/memory.c: handle_mm_fault()/handle_pte_fault() and do_wp_page()

Cabaniols> The third and last question is what is the role of the slab allocator ?
Cabaniols> When does a process asks for memory from a slab ? Is it used to build
Cabaniols> the stack the heap ? 

Slab allocator is a memory allocation and caching mechanism for
(small) kernel objects. It is described in, e.g., 

    http://nondot.org/sabre/os/files/MemManagement/SlabAllocator.pdf

Regards,
-velco

PS. You may also find help on irc.openprojects.net, #kernelnewbies

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