Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [git pull] cpus4096 tree, part 3 | Date | Sun, 4 Jan 2009 14:05:14 +1030 |
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On Sunday 04 January 2009 07:26:03 Linus Torvalds wrote: > > On Sat, 3 Jan 2009, Ingo Molnar wrote: > > > > > Has anybody looked at what the stack size is with MAXSMP set with an > > > allyesconfig? And what areas are still problematic, if any? Are we going > > > to have some code-paths that still essentially have 1kB+ of stack space > > > just because they haven't been converted and still have the cpu mask on > > > stack? > > > > ok, indeed testing of that is in order now. > > Well, since I can compile a allyesconfig pretty quickly, I did the static > part. It looks better than it used to, and I think most of the huge stacks > are totally unrealted to cpu masks. But not all. > > But it looks like we have a few: > > - flush_tlb_current_task: > cpumask_t cpu_mask; > - flush_tlb_mm: > cpumask_t cpu_mask; ... > - acpi_cpufreq_target: > cpumask_t online_policy_cpus
Mike? These are x86-specific...
> - local_cpus_show: > cpumask_t mask; > - local_cpulist_show: > cpumask_t mask;
Yes, this removal is still in my queue. I'll double-check that all the archs have the new "cpumask_of_pcibus". (cpumask:replace-and-remove-pcibus_to_cpumask.patch "cpumask: remove the now-obsoleted pcibus_to_cpumask()").
> and then we have a number of things that have "struct cpufreq_policy" on > the stack, and those things have two cpumask_t's in each.
Yep, we have the conversion for that too. Mike, it's cpumask:convert-drivers_acpi.patch "cpumask: convert struct cpufreq_policy to cpumask_var_t."
> The rest of the high-stack-usage cases - from a _very_ quick look - seem > to be unrelated to CPU masks, but in the "more than 1kB of stack" group > about a third (wild handwaving eyeballing) of them do seem to be related > to cpumask.
Mike was tracking this; I think he has a script to set NR_CPUS small then large and dump the changes.
Cheers, Rusty.
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