Re: [Libvir] CPU pinning of domains at creation time

Daniel Veillard wrote: >On Thu, Oct 11, 2007 at 10:45:44AM -0500, Ryan Harper wrote: > > >>* Daniel Veillard <veillard(a)redhat.com&gt; [2007-10-11 08:01]: >> >> >>> - for the mapping at the XML level I suggest to use a simple extension >>> to the <vcpu>n</vcpu> and extend it to >>> <vcpu cpuset='2,3'>n</vcpu> >>> with a limited syntax which is just the comma separated list of >>> allowed CPU numbers (if the code actually detects such a cpuset is >>> in effect i.e. in general this won't be added). >>> >>> >>I think we should support the same cpuset notation that Xen supports, >>which means including ranges (1-4) and negation (^1). These two >>features make describing large ranges much more compact. >> >> > > Enclosed is a rewrite of the cpuset notations, which can plug as >a replacement for the current code in xend_internals, it should support >the existing syntax currently used to parse xend topology strings, >and also alllow ranges and negation. It's not as a patch but as a >standlone replacement program which can be used to test (in spirit >of the old topology.c one from Beth). > I guess that's okay, check the test output (and possibly extend the >test cases in tests array), It tried to think of everything including >the weird \\n python xend bug and the 'no cpus' in cell cases. >Just dump tst.c in libvirt/src, add $(INCLUDES) to the >$(CC) $(CFLAGS) -I../include -o tst tst.c .... line and run >make tst >./tst >and check the output (also enclosed), > The parsing is done in a slightly different way, but that should >not change the output, > >Daniel > > > > > ... >------------------------------------------------------------------------ > cur = str; > while (*cur != 0) { > /* > * Find the next NUMA cell described in the xend output > */ > cur = strstr(cur, "node"); > if (cur == NULL) > break; > cur += 4; > cell = parseCpuNumber(&cur, maxcpu); > > This is certainly a nit, but I might change parseCpuNumber to parseNumber, since it looks a little odd that you are getting the cell id from the cpu number. A nit to be sure!

> if (cell < 0) > goto parse_error; > skipSpaces(&cur); > if (*cur != ':') > goto parse_error; > cur++; > skipSpaces(&cur); > if (!strncmp (cur, "no cpus", 7)) { > nb_cpus = 0; > for (cpu = 0;cpu < maxcpu;cpu++) > cpuset[cpu] = 0; > } else { > nb_cpus = parseCpuSet(conn, &cur, 'n', cpuset, maxcpu); > > Other than our discussion on #virt about handling of ^N specifications in parseCpuSet, looks good!