mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
synced 2025-01-12 08:48:48 +00:00
6cef7ff6e4
After merging all the relevant rwsem code into one single file, there
are a number of optimizations and cleanups that can be done:
1) Remove all the EXPORT_SYMBOL() calls for functions that are not
accessed elsewhere.
2) Remove all the __visible tags as none of the functions will be
called from assembly code anymore.
3) Make all the internal functions static.
4) Remove some unneeded blank lines.
5) Remove the intermediate rwsem_down_{read|write}_failed*() functions
and rename __rwsem_down_{read|write}_failed_common() to
rwsem_down_{read|write}_slowpath().
6) Remove "__" prefix of __rwsem_mark_wake().
7) Use atomic_long_try_cmpxchg_acquire() as much as possible.
8) Remove the rwsem_rtrylock and rwsem_wtrylock lock events as they
are not that useful.
That enables the compiler to do better optimization and reduce code
size. The text+data size of rwsem.o on an x86-64 machine with gcc8 was
reduced from 10237 bytes to 5030 bytes with this change.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Link: https://lkml.kernel.org/r/20190520205918.22251-6-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
66 lines
2.8 KiB
C
66 lines
2.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* 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; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* Authors: Waiman Long <longman@redhat.com>
|
|
*/
|
|
|
|
#ifndef LOCK_EVENT
|
|
#define LOCK_EVENT(name) LOCKEVENT_ ## name,
|
|
#endif
|
|
|
|
#ifdef CONFIG_QUEUED_SPINLOCKS
|
|
#ifdef CONFIG_PARAVIRT_SPINLOCKS
|
|
/*
|
|
* Locking events for PV qspinlock.
|
|
*/
|
|
LOCK_EVENT(pv_hash_hops) /* Average # of hops per hashing operation */
|
|
LOCK_EVENT(pv_kick_unlock) /* # of vCPU kicks issued at unlock time */
|
|
LOCK_EVENT(pv_kick_wake) /* # of vCPU kicks for pv_latency_wake */
|
|
LOCK_EVENT(pv_latency_kick) /* Average latency (ns) of vCPU kick */
|
|
LOCK_EVENT(pv_latency_wake) /* Average latency (ns) of kick-to-wakeup */
|
|
LOCK_EVENT(pv_lock_stealing) /* # of lock stealing operations */
|
|
LOCK_EVENT(pv_spurious_wakeup) /* # of spurious wakeups in non-head vCPUs */
|
|
LOCK_EVENT(pv_wait_again) /* # of wait's after queue head vCPU kick */
|
|
LOCK_EVENT(pv_wait_early) /* # of early vCPU wait's */
|
|
LOCK_EVENT(pv_wait_head) /* # of vCPU wait's at the queue head */
|
|
LOCK_EVENT(pv_wait_node) /* # of vCPU wait's at non-head queue node */
|
|
#endif /* CONFIG_PARAVIRT_SPINLOCKS */
|
|
|
|
/*
|
|
* Locking events for qspinlock
|
|
*
|
|
* Subtracting lock_use_node[234] from lock_slowpath will give you
|
|
* lock_use_node1.
|
|
*/
|
|
LOCK_EVENT(lock_pending) /* # of locking ops via pending code */
|
|
LOCK_EVENT(lock_slowpath) /* # of locking ops via MCS lock queue */
|
|
LOCK_EVENT(lock_use_node2) /* # of locking ops that use 2nd percpu node */
|
|
LOCK_EVENT(lock_use_node3) /* # of locking ops that use 3rd percpu node */
|
|
LOCK_EVENT(lock_use_node4) /* # of locking ops that use 4th percpu node */
|
|
LOCK_EVENT(lock_no_node) /* # of locking ops w/o using percpu node */
|
|
#endif /* CONFIG_QUEUED_SPINLOCKS */
|
|
|
|
/*
|
|
* Locking events for rwsem
|
|
*/
|
|
LOCK_EVENT(rwsem_sleep_reader) /* # of reader sleeps */
|
|
LOCK_EVENT(rwsem_sleep_writer) /* # of writer sleeps */
|
|
LOCK_EVENT(rwsem_wake_reader) /* # of reader wakeups */
|
|
LOCK_EVENT(rwsem_wake_writer) /* # of writer wakeups */
|
|
LOCK_EVENT(rwsem_opt_wlock) /* # of write locks opt-spin acquired */
|
|
LOCK_EVENT(rwsem_opt_fail) /* # of failed opt-spinnings */
|
|
LOCK_EVENT(rwsem_rlock) /* # of read locks acquired */
|
|
LOCK_EVENT(rwsem_rlock_fast) /* # of fast read locks acquired */
|
|
LOCK_EVENT(rwsem_rlock_fail) /* # of failed read lock acquisitions */
|
|
LOCK_EVENT(rwsem_wlock) /* # of write locks acquired */
|
|
LOCK_EVENT(rwsem_wlock_fail) /* # of failed write lock acquisitions */
|