Messages in this thread | | | Subject | Re: [RFD 4/9] Make total_forks per-cgroup | From | Peter Zijlstra <> | Date | Wed, 28 Sep 2011 14:53:38 +0200 |
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On Wed, 2011-09-28 at 14:42 +0200, Martin Schwidefsky wrote:
> > That is, am I missing some added value of all this cputime*() foo? > > C can do the math as long as the encoding of the cputime is simple enough. > Can we demand that a cputime value needs to be an integral type ?
I'd like to think we can ;-)
> What I did when I wrote all that stuff is to define cputime_t as a struct > that contains a single u64. That way I found all the places in the kernel > that used a cputime and could convert the code accordingly.
Indeed, that makes it a non-simple type and breaks all the C arith bits.
> My fear is that if the cputime_xxx operations are removed, code will > sneak in again that just uses an unsigned long instead of a cputime_t. > That would break any arch that requires something bigger than a u32 for > its cputime.
Which is only a problem for 32bit archs, of which s390 is the only one that matters, right? Hurm,. could we do something with sparse? Lots of people run sparse.
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