Re: CpuSet on PAGG (Re: PAGG in Open Source projects?)

Hi, Paul.
Thanks for your comments.

I also understood that CpuSet requires some more kernel changes,
like as sched_setaffinity() and so on, than PAGG provided.

But my main subject is not this point. The purpose of those patches is
to restrain incrementation of hook functions in fork() or exit().
I used PAGG for this, as a common event handling framework.

Currently CpuSet is the representative example widely known, and Job+CSA
and CKRM also require fork()/exit() event handling mechanism.
(CKRM uses ckrm_cb_fork(), PAGG uses pagg_attach())
Of course, above advanced features can't implement all of own functions
completely without some kernel modifications.

I have little motivation to implement CpuSet (or Job+CSA, CKRM) as
a kernel-loadable module. The main motivation is that those advanced
features use a common fork()/exit() event handling framework, and
it will make to restrain the unregulated hook functions in fork()/exit().

I chosen PAGG as a common event handling framework, merely.
But what I really wanted is a Common fork()/exit() event handling framework.
It may be called PAGG, or not.

Thanks.


Paul Jackson wrote:
 > I have a cpuset patch in Andrew Morton's *-mm patch series for several
 > months now, but I have not thought that it was a good candidate customer
 > of PAGG, for the main reason that my cpuset patch requires other kernel
 > changes, in the kernel memory allocator, and in the other calls that
 > manipulate scheduling (sched_setaffinity) and memory placement (mbind,
 > set_mempolicy), as well as in the /proc file system.  See the added
 > kernel files include/linux/cpuset.h and kernel/cpuset.c, for the central
 > portions of the cpuset patch in any *-mm release of the last few months.
 >
 > My understanding of PAGG is that it is especially useful in supporting
 > loadable modules that require to construct some grouping of the tasks on
 > a system, and that require to take some actions on key task events such
 > as fork and exit.  Since the cpuset's that I know require several
 > additional specialized hooks not provided by PAGG, I have concluded that
 > PAGG is not a valuable base for cpusets.  I have also concluded that
 > cpuset's is not a potential loadable module -- too many kernel hooks
 > required.
 >
 > Are you referring to these cpusets, or about some other facility by
 > that name?
 >
 > If you are referring to these same cpusets, then what benefit do you
 > consider that PAGG provides to these cpusets?

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Linux Promotion Center, NEC
KaiGai Kohei <[email protected]>