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Revision 32ffa4f71e10009498ae6b54da65ab316db967bd authored by Axel Rasmussen on 19 May 2021, 20:03:33 UTC, committed by Paolo Bonzini on 27 May 2021, 11:45:55 UTC 
KVM: selftests: compute correct demand paging size
 
This is a preparatory commit needed before we can use different kinds of
backing pages for guest memory.

Previously, we used perf_test_args.host_page_size, which is the host's
native page size (commonly 4K). For VM_MEM_SRC_ANONYMOUS this turns out
to be okay, but in a follow-up commit we want to allow using different
kinds of backing memory.

Take VM_MEM_SRC_ANONYMOUS_HUGETLB for example. Without this change, if
we used that backing page type, when we issued a UFFDIO_COPY ioctl we'd
only do so with 4K, rather than the full 2M of a backing hugepage. In
this case, UFFDIO_COPY returns -EINVAL (__mcopy_atomic_hugetlb checks
the size).

Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Message-Id: <20210519200339.829146-5-axelrasmussen@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 parent 25408e5
Raw File
debug_locks.c 
// SPDX-License-Identifier: GPL-2.0-only
/*
 * lib/debug_locks.c
 *
 * Generic place for common debugging facilities for various locks:
 * spinlocks, rwlocks, mutexes and rwsems.
 *
 * Started by Ingo Molnar:
 *
 *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 */
#include <linux/rwsem.h>
#include <linux/mutex.h>
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/debug_locks.h>

/*
 * We want to turn all lock-debugging facilities on/off at once,
 * via a global flag. The reason is that once a single bug has been
 * detected and reported, there might be cascade of followup bugs
 * that would just muddy the log. So we report the first one and
 * shut up after that.
 */
int debug_locks __read_mostly = 1;
EXPORT_SYMBOL_GPL(debug_locks);

/*
 * The locking-testsuite uses <debug_locks_silent> to get a
 * 'silent failure': nothing is printed to the console when
 * a locking bug is detected.
 */
int debug_locks_silent __read_mostly;
EXPORT_SYMBOL_GPL(debug_locks_silent);

/*
 * Generic 'turn off all lock debugging' function:
 */
noinstr int debug_locks_off(void)
{
	if (debug_locks && __debug_locks_off()) {
		if (!debug_locks_silent) {
			console_verbose();
			return 1;
		}
	}
	return 0;
}
EXPORT_SYMBOL_GPL(debug_locks_off);
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