Re: [tip:x86/microcode] x86/microcode_intel_early.c: Early updateucode on Intel's CPU
From: H. Peter Anvin
Date: Sat Dec 15 2012 - 16:41:30 EST
On 12/15/2012 12:55 PM, Yinghai Lu wrote:
On Sat, Dec 15, 2012 at 11:30 AM, H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> wrote:
What is the point of only managing 2M at a time? Now you have to have
more conditionals and you don't get any more memory efficiency.
We don't need to, because real_data is less than 2M, and ramdisk is about 16M.
In other words, you make magic assumptions (some of which are very wrong
in many real-life scenarios -- people can and do use gigabyte-plus
initramfs). That is exactly the wrong thing to do. Furthermore it
doesn't buy you anything, because you still have to allocate the PMDs.
Also if we set map too large, could have chance to cover mem hole near
1T for AMD HT system.
Again, should not be cachable in the MTRRs, and even so, is 1G aligned
already.
Filling arbitrarily into the brk is not acceptable... the brk is an O(1)
area and all brk allocations need to be reserved at compile time, so the
overflow handling is still necessary.
if run out of BRK, we will get panic, because early_make_pgtable will return -1.
And you consider that panic an acceptable failure mode????
and current BRK already have 64 slop space.
BTW, did you look at smp boot problem with early_level4_pgt version?
No, I have been busy with non-Linux stuff today.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
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