Re: [patch] voluntary-preempt-2.6.8.1-P0

[Ingo Molnar]

* Lee Revell <rlrevell@xxxxxxxxxxx> wrote:

> On Sun, 2004-08-15 at 22:58, Ingo Molnar wrote:
> > * Ingo Molnar <mingo@xxxxxxx> wrote:
> > i've attached mlock-test2.cc that should test this theory. The code
> > breaks up the mlock-ed region into 8 equal pieces and does mlock() on
> > them separately. It's basically a lock-break done in user-space. Does
> > this change the nature of xruns?
> 
> -ENOATTACHMENT

-ESTILLTOOEARLY. attached now.

	Ingo
// here is the code i used to test the mlockall caused xruns
#include <sys/mman.h>
#include <iostream>
#include <sstream>
#include <unistd.h>

#define INTERVALS 8

int main (int argc, char *argv[]) {
        if (argc < 2) {
                std::cout << "how many kbytes you want allocated and mlockall'ed?" << std::endl;
        }

        std::stringstream stream(argv[1]);
        int kbytes, error = 0, i, chunk;

        stream >> kbytes;
        char *mem = new char[kbytes*1024];
        std::cout << "filling with 0's" << std::endl;
        for (int i = 0; i < kbytes*1024; ++i) {
                mem[i] = 0;
        }

        std::cout << "ok, you want " << kbytes << "kb of memory mlocked.  going for it.." << std::endl;
	chunk = kbytes*1024/INTERVALS;
	for (i = 0; i < INTERVALS; i++)
        	error |= mlock(mem + i*chunk, chunk);
        if (error != 0) { std::cout << "mlock error" << std::endl; }
        else { std::cout << "mlock successfull" << std::endl;}
}