Re: Word-at-a-time dcache name accesses (was Re: .. anybody know ofany filesystems that depend on the exact VFS 'namehash' implementation?)

From: Dave Jones
Date: Tue Mar 27 2012 - 01:02:51 EST

On Tue, Mar 27, 2012 at 12:42:19AM -0400, Brian Gerst wrote:

> > I did only very limited profiling of the 32-bit case, but it's really
> > just four cheap ALU instructions there and didn't really show up at
> > all in the limited profiles I did. And at least I checked that the
> > code worked. I have to say that the advantage of "vectorizing" this
> > code is obviously much less if you can only do 4-byte "vectors", so I
> > didn't actually time whether the patch *improves* anything on x86-32.
> >
> This patch is causing my system (x86-64, Fedora 16) to fail to boot
> when DEBUG_PAGEALLOC=n. No oops, but these error messages were in the
> log for the bad kernel:

I saw this too, it was fixed by f132c5be05e407a99cf582347a2ae0120acd3ad7 for me.
Does your kernel have that commit ?


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