Messages in this thread | | | Date | Thu, 15 May 2014 00:17:48 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH 2/2] mm: replace remap_file_pages() syscall with emulation |
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On Wed, May 14, 2014 at 04:52:17PM -0400, Sasha Levin wrote: > On 05/12/2014 01:05 PM, Kirill A. Shutemov wrote: > > Taking into account your employment, is it possible to check how the RDBMS > > (old but it still supported 32-bit versions) would react on -ENOSYS here? > > Alrighty, I got an answer: > > 1. remap_file_pages() only works when the "VLM" feature of the db is enabled, > so those databases can work just fine without it, but be limited to 3-4GB of > memory. This is not needed at all on 64bit machines.
Okay. And it seems user need to enable it manually with option USE_INDIRECT_DATA_BUFFERS=TRUE.
http://docs.oracle.com/cd/B28359_01/server.111/b32009/appi_vlm.htm
> 2. As of OL7 (kernel 3.8), there will not be a 32bit kernel build. I'm still > waiting for an answer whether there will do a 32bit DB build for a 64bit kernel, > but that never happened before and seems unlikely. > > 3. They're basically saying that by the time upstream releases a kernel without > remap_file_pages() no one will need it here. > > To sum it up, they're fine with removing remap_file_pages().
Andrew, Linus, what will we do here: live with emulation or just kill the syscall? Or may be kill the syscall after few releases with emulation?
-- Kirill A. Shutemov
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