Re: [gentoo-user] Re: _syscallX isn't in linux-headers-2.6.20 ??

[Iain Buchanan]

On Thu, 2007-02-08 at 16:10 +1100, Christian Marie wrote:
> On Thu, Feb 08, 2007 at 10:23:09AM +0930, Iain Buchanan wrote:
> > Hi all,
> >
> > I'm trying to use:
> >
> > _syscall3(int, ioprio_set, int, which, int, who, int, ioprio);
> > _syscall2(int, ioprio_get, int, which, int, who);
> >
> > and supposedly I just
> >
> > #include <linux/unistd.h>
> >
> > but I'm getting these error from gcc:
> >
> > error: syntax error before "ioprio_set"
> > warning: data definition has no type or storage class
> > error: syntax error before "ioprio_get"
> > warning: data definition has no type or storage class
>
> Hi,
>
> It would be helpful to provide us with the failing code as we have no
> clue what you could be doing wrong.

sure - my question was more "where has the define for _syscall2 gone?",
but here is the code.  It comes
from /usr/src/linux/Documentation/block/ioprio.txt.  I compile it with:
$ gcc -o ionice ionice.c 
ionice.c:36: error: syntax error before "ioprio_set"
ionice.c:36: warning: data definition has no type or storage class
ionice.c:37: error: syntax error before "ioprio_get"
ionice.c:37: warning: data definition has no type or storage class

------begin ionice.c------
//
// Sample ionice utility copied from
// /usr/src/linux/Documentation/block/ioprio.txt from gentoo kernel version
// 2.6.19-suspend2-r1.  Probably (C) Jens Axboe <axboe@××××.de> and GPL'd?
//

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <getopt.h>
#include <unistd.h>
#include <sys/ptrace.h>

extern int sys_ioprio_set(int, int, int);
extern int sys_ioprio_get(int, int);

#if defined(__i386__)
#define __NR_ioprio_set		289
#define __NR_ioprio_get		290
#elif defined(__ppc__)
#define __NR_ioprio_set		273
#define __NR_ioprio_get		274
#elif defined(__x86_64__)
#define __NR_ioprio_set		251
#define __NR_ioprio_get		252
#elif defined(__ia64__)
#define __NR_ioprio_set		1274
#define __NR_ioprio_get		1275
#else
#error "Unsupported arch"
#endif

int ioprio_get(int which, int who);
int ioprio_set(int which, int who, int ioprio);

_syscall3(int, ioprio_set, int, which, int, who, int, ioprio);
_syscall2(int, ioprio_get, int, which, int, who);

enum {
	IOPRIO_CLASS_NONE,
	IOPRIO_CLASS_RT,
	IOPRIO_CLASS_BE,
	IOPRIO_CLASS_IDLE,
};

enum {
	IOPRIO_WHO_PROCESS = 1,
	IOPRIO_WHO_PGRP,
	IOPRIO_WHO_USER,
};

#define IOPRIO_CLASS_SHIFT	13

const char *to_prio[] = { "none", "realtime", "best-effort", "idle", };

int main(int argc, char *argv[])
{
	int ioprio = 4, set = 0, ioprio_class = IOPRIO_CLASS_BE;
	int c, pid = 0;

	while ((c = getopt(argc, argv, "+n:c:p:")) != EOF) {
		switch (c) {
		case 'n':
			ioprio = strtol(optarg, NULL, 10);
			set = 1;
			break;
		case 'c':
			ioprio_class = strtol(optarg, NULL, 10);
			set = 1;
			break;
		case 'p':
			pid = strtol(optarg, NULL, 10);
			break;
		}
	}

	switch (ioprio_class) {
		case IOPRIO_CLASS_NONE:
			ioprio_class = IOPRIO_CLASS_BE;
			break;
		case IOPRIO_CLASS_RT:
		case IOPRIO_CLASS_BE:
			break;
		case IOPRIO_CLASS_IDLE:
			ioprio = 7;
			break;
		default:
			printf("bad prio class %d\n", ioprio_class);
			return 1;
	}

	if (!set) {
		if (!pid && argv[optind])
			pid = strtol(argv[optind], NULL, 10);

		ioprio = ioprio_get(IOPRIO_WHO_PROCESS, pid);

		printf("pid=%d, %d\n", pid, ioprio);

		if (ioprio == -1)
			perror("ioprio_get");
		else {
			ioprio_class = ioprio >> IOPRIO_CLASS_SHIFT;
			ioprio = ioprio & 0xff;
			printf("%s: prio %d\n", to_prio[ioprio_class], ioprio);
		}
	} else {
		if (ioprio_set(IOPRIO_WHO_PROCESS, pid, ioprio | ioprio_class << IOPRIO_CLASS_SHIFT) == -1) {
			perror("ioprio_set");
			return 1;
		}

		if (argv[optind])
			execvp(argv[optind], &argv[optind]);
	}

	return 0;
}

------end ionice.c------

thanks,
-- 
Iain Buchanan <iaindb at netspace dot net dot au>

Progress might have been all right once, but it's gone on too long.
		-- Ogden Nash

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