Messages in this thread | | | Date | Sat, 29 Aug 2009 13:00:46 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] x86: reuse the boot-time mappings of fixed_addresses |
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* Xiao Guangrong <ericxiao.gr@gmail.com> wrote:
> From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> > > Some fixed_addresses items are only used when system boot, after > boot, they are free but no way to use, like early ioremap area. > They are wasted for us, we can reuse them after system boot. > > In this patch, we put them in permanent kmap's area and expand > vmalloc's address range. In boot time, reserve them in > permanent_kmaps_init() to avoid multiple used, after system boot, > we unreserved them then user can use it. > > Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> > --- > arch/x86/include/asm/fixmap.h | 2 ++ > arch/x86/include/asm/pgtable_32_types.h | 4 ++-- > arch/x86/mm/init_32.c | 8 ++++++++ > include/linux/highmem.h | 2 ++ > mm/highmem.c | 26 ++++++++++++++++++++++++++ > 5 files changed, 40 insertions(+), 2 deletions(-)
I'm wondering, how much space do we save this way, on a typical bootup on a typical PC?
Ingo
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