Re: [PATCH v2 11/25] powerpc/8xx: map 16M RAM at startup
From: Christophe Leroy <hidden>
Date: 2015-10-06 14:10:41
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Le 29/09/2015 01:58, Scott Wood a écrit :
On Tue, Sep 22, 2015 at 06:50:50PM +0200, Christophe Leroy wrote:quoted
On recent kernels, with some debug options like for instance CONFIG_LOCKDEP, the BSS requires more than 8M memory, allthough the kernel code fits in the first 8M. Today, it is necessary to activate CONFIG_PIN_TLB to get more than 8M at startup, allthough pinning TLB is not necessary for that. This patch adds a second 8M page to the initial mapping in order to have 16M mapped regardless of CONFIG_PIN_TLB, like several other 32 bits PPC (40x, 601, ...) Signed-off-by: Christophe Leroy <redacted> ---Is the assumption that nobody is still running 8xx systems with only 8 MiB RAM on current kernels?
No, setup_initial_memory_limit() limits the memory to the minimum between 16M and the real memory size, so if a platform has only 8M, it will still be limited to 8M even with 16M mapped. Christophe