On Thu, 2008-08-21 at 10:14 +0200, Arnd Bergmann wrote:

On Thursday 21 August 2008, Paul Mackerras wrote:

quoted

Arnd Bergmann writes:

quoted

Paul, any chance we can still get this into 2.6.27?

Possibly.  We'll need a really good explanation for Linus as to why
this is needed (what regression or serious bug this fixes) and why it
is late.  Can you send me something explaining that?

The patch does not fix a regression, the spu-oprofile code basically never
worked. With the current code in Linux, samples in the profile buffer
can get corrupted because reader and writer to that buffer use different
locks for accessing it.

Actually for me it worked[1] a reasonable amount of the time, enough to
be useful. So the spu-oprofile code has always been broken in this way,
but it's not always fatal. So the patch doesn't fix a regression, but it
fixes a serious user-visible bug, which makes it legit rc4 material
IMHO.

[1] that was late last year, so possibly a kernel or two ago.

cheers

-- 
Michael Ellerman
OzLabs, IBM Australia Development Lab

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

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