On Mon, Dec 21, 2015 at 10:48:22AM -0500, Luiz Capitulino wrote: > On Sat, 19 Dec 2015 22:57:30 -0200 > Marcelo Tosatti <mtosa...@redhat.com> wrote: > > > On Sat, Dec 19, 2015 at 11:42:57AM +0100, Thomas Gleixner wrote: > > > On Thu, 17 Dec 2015, Fenghua Yu wrote: > > > > > > > From: Fenghua Yu <fenghua...@intel.com> > > > > > > > > From: Vikas Shivappa <vikas.shiva...@linux.intel.com> > > > > > > > > Add a new cgroup 'intel_rdt' to manage cache allocation. Each cgroup > > > > directory is associated with a class of service id(closid). To map a > > > > task with closid during scheduling, this patch removes the closid field > > > > from task_struct and uses the already existing 'cgroups' field in > > > > task_struct. > > > > > > > > The cgroup has a file 'l3_cbm' which represents the L3 cache capacity > > > > bitmask(CBM). The CBM is global for the whole system currently. The > > > > capacity bitmask needs to have only contiguous bits set and number of > > > > bits that can be set is less than the max bits that can be set. The > > > > tasks belonging to a cgroup get to fill in the L3 cache represented by > > > > the capacity bitmask of the cgroup. For ex: if the max bits in the CBM > > > > is 10 and the cache size is 10MB, each bit represents 1MB of cache > > > > capacity. > > > > > > > > Root cgroup always has all the bits set in the l3_cbm. User can create > > > > more cgroups with mkdir syscall. By default the child cgroups inherit > > > > the capacity bitmask(CBM) from parent. User can change the CBM specified > > > > in hex for each cgroup. Each unique bitmask is associated with a class > > > > of service ID and an -ENOSPC is returned once we run out of > > > > closids. > > > > > > This is still the original crap. No, we are not introducing this > > > interface now just because we can. I explained in great length why > > > this is completely useless and what we really need. > > > > > > Thanks, > > > > > > tglx > > > > Can you make a summary of the points, and enumerate them, please. > > (what are the problems of the current interface, and why such problems > > are fixed in the new interface?). > > Marcelo, you participated on the discussions. We discussed why this > is a bad interface a *lot* in the v15 posting. There are two writeups > that summarize all the problems: > > - https://lkml.org/lkml/2015/11/18/637
OK cool hopefully that makes it clear to Fenghua Yu what must be changed in the patchset. > - http://lkml.iu.edu/hypermail/linux/kernel/1511.0/02375.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
