Commit 7c5f6b32 authored by Eric Biggers's avatar Eric Biggers Committed by Theodore Ts'o

blockgroup_lock.h: simplify definition of NR_BG_LOCKS

We can use ilog2() to more easily produce the desired NR_BG_LOCKS.  This
works because ilog2() is evaluated at compile-time when its argument is
a compile-time constant.

I did not change the chosen NR_BG_LOCKS values.
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarAndreas Dilger <adilger@dilger.ca>
parent 9e5ab85d
......@@ -10,28 +10,10 @@
#include <linux/cache.h>
#ifdef CONFIG_SMP
/*
* We want a power-of-two. Is there a better way than this?
*/
#if NR_CPUS >= 32
#define NR_BG_LOCKS 128
#elif NR_CPUS >= 16
#define NR_BG_LOCKS 64
#elif NR_CPUS >= 8
#define NR_BG_LOCKS 32
#elif NR_CPUS >= 4
#define NR_BG_LOCKS 16
#elif NR_CPUS >= 2
#define NR_BG_LOCKS 8
#define NR_BG_LOCKS (4 << ilog2(NR_CPUS < 32 ? NR_CPUS : 32))
#else
#define NR_BG_LOCKS 4
#endif
#else /* CONFIG_SMP */
#define NR_BG_LOCKS 1
#endif /* CONFIG_SMP */
#endif
struct bgl_lock {
spinlock_t lock;
......
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