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Revision 85b144f860176ec18db927d6d9ecdfb24d9c6483 authored by Maarten Lankhorst on 29 November 2012, 11:36:54 UTC, committed by Dave Airlie on 10 December 2012, 10:21:03 UTC 
drm/ttm: call ttm_bo_cleanup_refs with reservation and lru lock held, v3
 
By removing the unlocking of lru and retaking it immediately, a race is
removed where the bo is taken off the swap list or the lru list between
the unlock and relock. As such the cleanup_refs code can be simplified,
it will attempt to call ttm_bo_wait non-blockingly, and if it fails
it will drop the locks and perform a blocking wait, or return an error
if no_wait_gpu was set.

The need for looping is also eliminated, since swapout and evict_mem_first
will always follow the destruction path, no new fence is allowed
to be attached. As far as I can see this may already have been the case,
but the unlocking / relocking required a complicated loop to deal with
re-reservation.

Changes since v1:
 - Simplify no_wait_gpu case by folding it in with empty ddestroy.
 - Hold a reservation while calling ttm_bo_cleanup_memtype_use again.
Changes since v2:
 - Do not remove bo from lru list while waiting

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
1 parent 6ed9ccb
Raw File
backtracetest.c 
/*
 * Simple stack backtrace regression test module
 *
 * (C) Copyright 2008 Intel Corporation
 * Author: Arjan van de Ven <arjan@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2
 * of the License.
 */

#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/stacktrace.h>

static void backtrace_test_normal(void)
{
	printk("Testing a backtrace from process context.\n");
	printk("The following trace is a kernel self test and not a bug!\n");

	dump_stack();
}

static DECLARE_COMPLETION(backtrace_work);

static void backtrace_test_irq_callback(unsigned long data)
{
	dump_stack();
	complete(&backtrace_work);
}

static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0);

static void backtrace_test_irq(void)
{
	printk("Testing a backtrace from irq context.\n");
	printk("The following trace is a kernel self test and not a bug!\n");

	init_completion(&backtrace_work);
	tasklet_schedule(&backtrace_tasklet);
	wait_for_completion(&backtrace_work);
}

#ifdef CONFIG_STACKTRACE
static void backtrace_test_saved(void)
{
	struct stack_trace trace;
	unsigned long entries[8];

	printk("Testing a saved backtrace.\n");
	printk("The following trace is a kernel self test and not a bug!\n");

	trace.nr_entries = 0;
	trace.max_entries = ARRAY_SIZE(entries);
	trace.entries = entries;
	trace.skip = 0;

	save_stack_trace(&trace);
	print_stack_trace(&trace, 0);
}
#else
static void backtrace_test_saved(void)
{
	printk("Saved backtrace test skipped.\n");
}
#endif

static int backtrace_regression_test(void)
{
	printk("====[ backtrace testing ]===========\n");

	backtrace_test_normal();
	backtrace_test_irq();
	backtrace_test_saved();

	printk("====[ end of backtrace testing ]====\n");
	return 0;
}

static void exitf(void)
{
}

module_init(backtrace_regression_test);
module_exit(exitf);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
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