Messages in this thread | | | Date | Thu, 14 May 2009 13:48:39 +0200 | From | Michał Nazarewicz <> | Subject | Re: [PATCH] Physical Memory Management [0/1] |
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> On Thu, 2009-05-14 at 11:00 +0200, Michał Nazarewicz wrote: >> PMM solves this problem since the buffers are allocated when they >> are needed.
On Thu, 14 May 2009 13:20:02 +0200, Peter Zijlstra wrote: > Ha - only when you actually manage to allocate things. Physically > contiguous allocations are exceedingly hard once the machine has been > running for a while.
PMM reserves memory during boot time using alloc_bootmem_low_pages(). After this is done, it can allocate buffers from reserved pool.
The idea here is that there are n hardware accelerators, each can operate on 1MiB blocks (to simplify assume that's the case). However, we know that at most m < n devices will be used at the same time so instead of reserving n MiBs of memory we reserve only m MiBs.
-- Best regards, _ _ .o. | Liege of Serenly Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michał "mina86" Nazarewicz (o o) ooo +-<m.nazarewicz@samsung.com>-<mina86@jabber.org>-ooO--(_)--Ooo--
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