linux-next/include/linux/mmap_lock.h
Andrew Morton d61c30c02e mm-introduce-mmap_lock_speculate_try_beginretry-fix
use read_seqcount_retry() in mmap_lock_speculate_retry(), per Wei Yang

Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-18 19:50:50 -08:00

232 lines
6.0 KiB
C

#ifndef _LINUX_MMAP_LOCK_H
#define _LINUX_MMAP_LOCK_H
#include <linux/lockdep.h>
#include <linux/mm_types.h>
#include <linux/mmdebug.h>
#include <linux/rwsem.h>
#include <linux/tracepoint-defs.h>
#include <linux/types.h>
#define MMAP_LOCK_INITIALIZER(name) \
.mmap_lock = __RWSEM_INITIALIZER((name).mmap_lock),
DECLARE_TRACEPOINT(mmap_lock_start_locking);
DECLARE_TRACEPOINT(mmap_lock_acquire_returned);
DECLARE_TRACEPOINT(mmap_lock_released);
#ifdef CONFIG_TRACING
void __mmap_lock_do_trace_start_locking(struct mm_struct *mm, bool write);
void __mmap_lock_do_trace_acquire_returned(struct mm_struct *mm, bool write,
bool success);
void __mmap_lock_do_trace_released(struct mm_struct *mm, bool write);
static inline void __mmap_lock_trace_start_locking(struct mm_struct *mm,
bool write)
{
if (tracepoint_enabled(mmap_lock_start_locking))
__mmap_lock_do_trace_start_locking(mm, write);
}
static inline void __mmap_lock_trace_acquire_returned(struct mm_struct *mm,
bool write, bool success)
{
if (tracepoint_enabled(mmap_lock_acquire_returned))
__mmap_lock_do_trace_acquire_returned(mm, write, success);
}
static inline void __mmap_lock_trace_released(struct mm_struct *mm, bool write)
{
if (tracepoint_enabled(mmap_lock_released))
__mmap_lock_do_trace_released(mm, write);
}
#else /* !CONFIG_TRACING */
static inline void __mmap_lock_trace_start_locking(struct mm_struct *mm,
bool write)
{
}
static inline void __mmap_lock_trace_acquire_returned(struct mm_struct *mm,
bool write, bool success)
{
}
static inline void __mmap_lock_trace_released(struct mm_struct *mm, bool write)
{
}
#endif /* CONFIG_TRACING */
static inline void mmap_assert_locked(const struct mm_struct *mm)
{
rwsem_assert_held(&mm->mmap_lock);
}
static inline void mmap_assert_write_locked(const struct mm_struct *mm)
{
rwsem_assert_held_write(&mm->mmap_lock);
}
#ifdef CONFIG_PER_VMA_LOCK
static inline void mm_lock_seqcount_init(struct mm_struct *mm)
{
seqcount_init(&mm->mm_lock_seq);
}
static inline void mm_lock_seqcount_begin(struct mm_struct *mm)
{
do_raw_write_seqcount_begin(&mm->mm_lock_seq);
}
static inline void mm_lock_seqcount_end(struct mm_struct *mm)
{
ASSERT_EXCLUSIVE_WRITER(mm->mm_lock_seq);
do_raw_write_seqcount_end(&mm->mm_lock_seq);
}
static inline bool mmap_lock_speculate_try_begin(struct mm_struct *mm, unsigned int *seq)
{
/*
* Since mmap_lock is a sleeping lock, and waiting for it to become
* unlocked is more or less equivalent with taking it ourselves, don't
* bother with the speculative path if mmap_lock is already write-locked
* and take the slow path, which takes the lock.
*/
return raw_seqcount_try_begin(&mm->mm_lock_seq, *seq);
}
static inline bool mmap_lock_speculate_retry(struct mm_struct *mm, unsigned int seq)
{
return read_seqcount_retry(&mm->mm_lock_seq, seq);
}
#else /* CONFIG_PER_VMA_LOCK */
static inline void mm_lock_seqcount_init(struct mm_struct *mm) {}
static inline void mm_lock_seqcount_begin(struct mm_struct *mm) {}
static inline void mm_lock_seqcount_end(struct mm_struct *mm) {}
static inline bool mmap_lock_speculate_try_begin(struct mm_struct *mm, unsigned int *seq)
{
return false;
}
static inline bool mmap_lock_speculate_retry(struct mm_struct *mm, unsigned int seq)
{
return true;
}
#endif /* CONFIG_PER_VMA_LOCK */
static inline void mmap_init_lock(struct mm_struct *mm)
{
init_rwsem(&mm->mmap_lock);
mm_lock_seqcount_init(mm);
}
static inline void mmap_write_lock(struct mm_struct *mm)
{
__mmap_lock_trace_start_locking(mm, true);
down_write(&mm->mmap_lock);
mm_lock_seqcount_begin(mm);
__mmap_lock_trace_acquire_returned(mm, true, true);
}
static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
{
__mmap_lock_trace_start_locking(mm, true);
down_write_nested(&mm->mmap_lock, subclass);
mm_lock_seqcount_begin(mm);
__mmap_lock_trace_acquire_returned(mm, true, true);
}
static inline int mmap_write_lock_killable(struct mm_struct *mm)
{
int ret;
__mmap_lock_trace_start_locking(mm, true);
ret = down_write_killable(&mm->mmap_lock);
if (!ret)
mm_lock_seqcount_begin(mm);
__mmap_lock_trace_acquire_returned(mm, true, ret == 0);
return ret;
}
/*
* Drop all currently-held per-VMA locks.
* This is called from the mmap_lock implementation directly before releasing
* a write-locked mmap_lock (or downgrading it to read-locked).
* This should normally NOT be called manually from other places.
* If you want to call this manually anyway, keep in mind that this will release
* *all* VMA write locks, including ones from further up the stack.
*/
static inline void vma_end_write_all(struct mm_struct *mm)
{
mmap_assert_write_locked(mm);
mm_lock_seqcount_end(mm);
}
static inline void mmap_write_unlock(struct mm_struct *mm)
{
__mmap_lock_trace_released(mm, true);
vma_end_write_all(mm);
up_write(&mm->mmap_lock);
}
static inline void mmap_write_downgrade(struct mm_struct *mm)
{
__mmap_lock_trace_acquire_returned(mm, false, true);
vma_end_write_all(mm);
downgrade_write(&mm->mmap_lock);
}
static inline void mmap_read_lock(struct mm_struct *mm)
{
__mmap_lock_trace_start_locking(mm, false);
down_read(&mm->mmap_lock);
__mmap_lock_trace_acquire_returned(mm, false, true);
}
static inline int mmap_read_lock_killable(struct mm_struct *mm)
{
int ret;
__mmap_lock_trace_start_locking(mm, false);
ret = down_read_killable(&mm->mmap_lock);
__mmap_lock_trace_acquire_returned(mm, false, ret == 0);
return ret;
}
static inline bool mmap_read_trylock(struct mm_struct *mm)
{
bool ret;
__mmap_lock_trace_start_locking(mm, false);
ret = down_read_trylock(&mm->mmap_lock) != 0;
__mmap_lock_trace_acquire_returned(mm, false, ret);
return ret;
}
static inline void mmap_read_unlock(struct mm_struct *mm)
{
__mmap_lock_trace_released(mm, false);
up_read(&mm->mmap_lock);
}
static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
{
__mmap_lock_trace_released(mm, false);
up_read_non_owner(&mm->mmap_lock);
}
static inline int mmap_lock_is_contended(struct mm_struct *mm)
{
return rwsem_is_contended(&mm->mmap_lock);
}
#endif /* _LINUX_MMAP_LOCK_H */