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File: [Development] / linux-2.6-xfs / arch / mips / kernel / mips-mt-fpaff.c (download)

Revision 1.1, Wed Sep 12 17:09:56 2007 UTC (10 years, 1 month ago) by tes.longdrop.melbourne.sgi.com
Branch: MAIN

Update 2.6.x-xfs to 2.6.23-rc4.

Also update fs/xfs with external mainline changes.
There were 12 such missing commits that I detected:

--------
commit ad690ef9e690f6c31f7d310b09ef1314bcec9033
Author: Al Viro <viro@ftp.linux.org.uk>
    xfs ioctl __user annotations

commit 20c2df83d25c6a95affe6157a4c9cac4cf5ffaac
Author: Paul Mundt <lethal@linux-sh.org>
    mm: Remove slab destructors from kmem_cache_create().

commit d0217ac04ca6591841e5665f518e38064f4e65bd
Author: Nick Piggin <npiggin@suse.de>
    mm: fault feedback #1

commit 54cb8821de07f2ffcd28c380ce9b93d5784b40d7
Author: Nick Piggin <npiggin@suse.de>
    mm: merge populate and nopage into fault (fixes nonlinear)

commit d00806b183152af6d24f46f0c33f14162ca1262a
Author: Nick Piggin <npiggin@suse.de>
    mm: fix fault vs invalidate race for linear mappings

commit a569425512253992cc64ebf8b6d00a62f986db3e
Author: Christoph Hellwig <hch@infradead.org>
    knfsd: exportfs: add exportfs.h header

commit 831441862956fffa17b9801db37e6ea1650b0f69
Author: Rafael J. Wysocki <rjw@sisk.pl>
    Freezer: make kernel threads nonfreezable by default

commit 8e1f936b73150f5095448a0fee6d4f30a1f9001d
Author: Rusty Russell <rusty@rustcorp.com.au>
    mm: clean up and kernelify shrinker registration

commit 5ffc4ef45b3b0a57872f631b4e4ceb8ace0d7496
Author: Jens Axboe <jens.axboe@oracle.com>
    sendfile: remove .sendfile from filesystems that use generic_file_sendfile()

commit 8bb7844286fb8c9fce6f65d8288aeb09d03a5e0d
Author: Rafael J. Wysocki <rjw@sisk.pl>
    Add suspend-related notifications for CPU hotplug

commit 59c51591a0ac7568824f541f57de967e88adaa07
Author: Michael Opdenacker <michael@free-electrons.com>
    Fix occurrences of "the the "

commit 0ceb331433e8aad9c5f441a965d7c681f8b9046f
Author: Dmitriy Monakhov <dmonakhov@openvz.org>
    mm: move common segment checks to separate helper function
--------
Merge of 2.6.x-xfs-melb:linux:29656b by kenmcd.

/*
 * General MIPS MT support routines, usable in AP/SP, SMVP, or SMTC kernels
 * Copyright (C) 2005 Mips Technologies, Inc
 */
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/security.h>
#include <linux/types.h>
#include <asm/uaccess.h>

/*
 * CPU mask used to set process affinity for MT VPEs/TCs with FPUs
 */
cpumask_t mt_fpu_cpumask;

static int fpaff_threshold = -1;
unsigned long mt_fpemul_threshold = 0;

/*
 * Replacement functions for the sys_sched_setaffinity() and
 * sys_sched_getaffinity() system calls, so that we can integrate
 * FPU affinity with the user's requested processor affinity.
 * This code is 98% identical with the sys_sched_setaffinity()
 * and sys_sched_getaffinity() system calls, and should be
 * updated when kernel/sched.c changes.
 */

/*
 * find_process_by_pid - find a process with a matching PID value.
 * used in sys_sched_set/getaffinity() in kernel/sched.c, so
 * cloned here.
 */
static inline struct task_struct *find_process_by_pid(pid_t pid)
{
	return pid ? find_task_by_pid(pid) : current;
}


/*
 * mipsmt_sys_sched_setaffinity - set the cpu affinity of a process
 */
asmlinkage long mipsmt_sys_sched_setaffinity(pid_t pid, unsigned int len,
				      unsigned long __user *user_mask_ptr)
{
	cpumask_t new_mask;
	cpumask_t effective_mask;
	int retval;
	struct task_struct *p;
	struct thread_info *ti;

	if (len < sizeof(new_mask))
		return -EINVAL;

	if (copy_from_user(&new_mask, user_mask_ptr, sizeof(new_mask)))
		return -EFAULT;

	lock_cpu_hotplug();
	read_lock(&tasklist_lock);

	p = find_process_by_pid(pid);
	if (!p) {
		read_unlock(&tasklist_lock);
		unlock_cpu_hotplug();
		return -ESRCH;
	}

	/*
	 * It is not safe to call set_cpus_allowed with the
	 * tasklist_lock held.  We will bump the task_struct's
	 * usage count and drop tasklist_lock before invoking
	 * set_cpus_allowed.
	 */
	get_task_struct(p);

	retval = -EPERM;
	if ((current->euid != p->euid) && (current->euid != p->uid) &&
			!capable(CAP_SYS_NICE)) {
		read_unlock(&tasklist_lock);
		goto out_unlock;
	}

	retval = security_task_setscheduler(p, 0, NULL);
	if (retval)
		goto out_unlock;

	/* Record new user-specified CPU set for future reference */
	p->thread.user_cpus_allowed = new_mask;

	/* Unlock the task list */
	read_unlock(&tasklist_lock);

	/* Compute new global allowed CPU set if necessary */
	ti = task_thread_info(p);
	if (test_ti_thread_flag(ti, TIF_FPUBOUND) &&
	    cpus_intersects(new_mask, mt_fpu_cpumask)) {
		cpus_and(effective_mask, new_mask, mt_fpu_cpumask);
		retval = set_cpus_allowed(p, effective_mask);
	} else {
		clear_ti_thread_flag(ti, TIF_FPUBOUND);
		retval = set_cpus_allowed(p, new_mask);
	}

out_unlock:
	put_task_struct(p);
	unlock_cpu_hotplug();
	return retval;
}

/*
 * mipsmt_sys_sched_getaffinity - get the cpu affinity of a process
 */
asmlinkage long mipsmt_sys_sched_getaffinity(pid_t pid, unsigned int len,
				      unsigned long __user *user_mask_ptr)
{
	unsigned int real_len;
	cpumask_t mask;
	int retval;
	struct task_struct *p;

	real_len = sizeof(mask);
	if (len < real_len)
		return -EINVAL;

	lock_cpu_hotplug();
	read_lock(&tasklist_lock);

	retval = -ESRCH;
	p = find_process_by_pid(pid);
	if (!p)
		goto out_unlock;
	retval = security_task_getscheduler(p);
	if (retval)
		goto out_unlock;

	cpus_and(mask, p->thread.user_cpus_allowed, cpu_possible_map);

out_unlock:
	read_unlock(&tasklist_lock);
	unlock_cpu_hotplug();
	if (retval)
		return retval;
	if (copy_to_user(user_mask_ptr, &mask, real_len))
		return -EFAULT;
	return real_len;
}


static int __init fpaff_thresh(char *str)
{
	get_option(&str, &fpaff_threshold);
	return 1;
}
__setup("fpaff=", fpaff_thresh);

/*
 * FPU Use Factor empirically derived from experiments on 34K
 */
#define FPUSEFACTOR 333

static __init int mt_fp_affinity_init(void)
{
	if (fpaff_threshold >= 0) {
		mt_fpemul_threshold = fpaff_threshold;
	} else {
		mt_fpemul_threshold =
			(FPUSEFACTOR * (loops_per_jiffy/(500000/HZ))) / HZ;
	}
	printk(KERN_DEBUG "FPU Affinity set after %ld emulations\n",
	       mt_fpemul_threshold);

	return 0;
}
arch_initcall(mt_fp_affinity_init);