mirrors/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2025-11-04 02:30:34 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

locking/lockdep: Use __jhash_mix() for iterate_chain_key()

Browse source 
Use __jhash_mix() to mix the class_idx into the class_key. This
function provides better mixing than the previously used, home grown
mix function.

Leave hashing to the professionals :-)

Suggested-by: George Spelvin <linux@sciencehorizons.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2016-05-30 18:31:33 +02:00 committed by Ingo Molnar
parent ed8ebd1d51
commit dfaaf3fa01
1 changed files with 9 additions and 4 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

13
kernel/locking/lockdep.c
View file

@ -46,6 +46,7 @@
#include <linux/gfp.h> #include <linux/gfp.h>
#include <linux/kmemcheck.h> #include <linux/kmemcheck.h>
#include <linux/random.h> #include <linux/random.h>
#include <linux/jhash.h>
#include <asm/sections.h> #include <asm/sections.h>
@ -309,10 +310,14 @@ static struct hlist_head chainhash_table[CHAINHASH_SIZE];
* It's a 64-bit hash, because it's important for the keys to be * It's a 64-bit hash, because it's important for the keys to be
* unique. * unique.
*/ */
#define iterate_chain_key(key1, key2) \ static inline u64 iterate_chain_key(u64 key, u32 idx)
(((key1) << MAX_LOCKDEP_KEYS_BITS) ^ \ {
((key1) >> (64-MAX_LOCKDEP_KEYS_BITS)) ^ \ u32 k0 = key, k1 = key >> 32;
(key2))
__jhash_mix(idx, k0, k1); /* Macro that modifies arguments! */
return k0 | (u64)k1 << 32;
}
void lockdep_off(void) void lockdep_off(void)
{ {