From: Peter Zijlstra <peterz@infradead.org>
To: andrealmeid@collabora.com, tglx@linutronix.de, mingo@redhat.com,
dvhart@infradead.org, rostedt@goodmis.org, bigeasy@linutronix.de
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
kernel@collabora.com, krisman@collabora.com,
linux-api@vger.kernel.org, libc-alpha@sourceware.org,
mtk.manpages@gmail.com, dave@stgolabs.net, arnd@arndb.de
Subject: [PATCH 15/20] futex: Simplify double_lock_hb()
Date: Wed, 15 Sep 2021 16:07:25 +0200 [thread overview]
Message-ID: <20210915141525.556892413@infradead.org> (raw)
In-Reply-To: 20210915140710.596174479@infradead.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/futex/futex.h | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
--- a/kernel/futex/futex.h
+++ b/kernel/futex/futex.h
@@ -316,14 +316,12 @@ extern void futex_q_unlock(struct futex_
static inline void
double_lock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2)
{
- if (hb1 <= hb2) {
- spin_lock(&hb1->lock);
- if (hb1 < hb2)
- spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING);
- } else { /* hb1 > hb2 */
- spin_lock(&hb2->lock);
- spin_lock_nested(&hb1->lock, SINGLE_DEPTH_NESTING);
- }
+ if (hb1 > hb2)
+ swap(hb1, hb2);
+
+ spin_lock(&hb1->lock);
+ if (hb1 != hb2)
+ spin_lock_nested(&hb2->lock, SINGLE_DEPTH_NESTING);
}
static inline void
next prev parent reply other threads:[~2021-09-15 14:17 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-15 14:07 [PATCH 00/20] futex: splitup and waitv syscall Peter Zijlstra
2021-09-15 14:07 ` [PATCH 01/20] futex: Move to kernel/futex/ Peter Zijlstra
2021-09-15 14:07 ` [PATCH 02/20] futex: Split out syscalls Peter Zijlstra
2021-09-15 14:07 ` [PATCH 03/20] futex: Rename {,__}{,un}queue_me() Peter Zijlstra
2021-09-15 14:07 ` [PATCH 04/20] futex: Rename futex_wait_queue_me() Peter Zijlstra
2021-09-15 14:07 ` [PATCH 05/20] futex: Rename: queue_{,un}lock() Peter Zijlstra
2021-09-15 14:07 ` [PATCH 06/20] futex: Rename __unqueue_futex() Peter Zijlstra
2021-09-15 14:07 ` [PATCH 07/20] futex: Rename hash_futex() Peter Zijlstra
2021-09-15 15:17 ` André Almeida
2021-09-15 15:22 ` Peter Zijlstra
2021-09-15 14:07 ` [PATCH 08/20] futex: Rename: {get,cmpxchg}_futex_value_locked() Peter Zijlstra
2021-09-15 14:07 ` [PATCH 09/20] futex: Split out PI futex Peter Zijlstra
2021-09-15 14:07 ` [PATCH 10/20] futex: Rename: hb_waiter_{inc,dec,pending}() Peter Zijlstra
2021-09-15 14:07 ` [PATCH 11/20] futex: Rename: match_futex() Peter Zijlstra
2021-09-15 14:07 ` [PATCH 12/20] futex: Rename mark_wake_futex() Peter Zijlstra
2021-09-15 14:07 ` [PATCH 13/20] futex: Split out requeue Peter Zijlstra
2021-09-15 14:07 ` [PATCH 14/20] futex: Split out wait/wake Peter Zijlstra
2021-09-15 14:07 ` Peter Zijlstra [this message]
2021-09-15 15:13 ` [PATCH 00/20] futex: splitup and waitv syscall André Almeida
[not found] ` <20210915141525.621568509@infradead.org>
2021-09-15 15:20 ` [PATCH 16/20] futex: Implement sys_futex_waitv() André Almeida
2021-09-15 15:37 ` Peter Zijlstra
2021-09-15 17:34 ` Paul Eggert
2021-09-16 14:49 ` Thomas Gleixner
2021-09-16 18:54 ` André Almeida
2021-09-15 18:47 ` Arnd Bergmann
2021-09-15 16:29 ` André Almeida
2021-09-15 18:24 ` [PATCH 00/20] futex: splitup and waitv syscall André Almeida
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