lkml.org 
[lkml]   [2020]   [Mar]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    Subject[PATCH v2 01/10] mmap locking API: initial implementation as rwsem wrappers
    From
    This change wraps the existing mmap_sem related rwsem calls into a new
    mmap locking API. There are two justifications for the new API:

    - At first, it provides an easy hooking point to instrument mmap_sem
    locking latencies independently of any other rwsems.

    - In the future, it may be a starting point for replacing the rwsem
    implementation with a different one, such as range locks.

    Signed-off-by: Michel Lespinasse <walken@google.com>
    ---
    include/linux/mm.h | 1 +
    include/linux/mmap_lock.h | 59 +++++++++++++++++++++++++++++++++++++++
    2 files changed, 60 insertions(+)
    create mode 100644 include/linux/mmap_lock.h

    diff --git a/include/linux/mm.h b/include/linux/mm.h
    index c54fb96cb1e6..2f13c9198999 100644
    --- a/include/linux/mm.h
    +++ b/include/linux/mm.h
    @@ -15,6 +15,7 @@
    #include <linux/atomic.h>
    #include <linux/debug_locks.h>
    #include <linux/mm_types.h>
    +#include <linux/mmap_lock.h>
    #include <linux/range.h>
    #include <linux/pfn.h>
    #include <linux/percpu-refcount.h>
    diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
    new file mode 100644
    index 000000000000..cffd25afe92b
    --- /dev/null
    +++ b/include/linux/mmap_lock.h
    @@ -0,0 +1,59 @@
    +#ifndef _LINUX_MMAP_LOCK_H
    +#define _LINUX_MMAP_LOCK_H
    +
    +static inline void mmap_init_lock(struct mm_struct *mm)
    +{
    + init_rwsem(&mm->mmap_sem);
    +}
    +
    +static inline void mmap_write_lock(struct mm_struct *mm)
    +{
    + down_write(&mm->mmap_sem);
    +}
    +
    +static inline int mmap_write_lock_killable(struct mm_struct *mm)
    +{
    + return down_write_killable(&mm->mmap_sem);
    +}
    +
    +static inline bool mmap_write_trylock(struct mm_struct *mm)
    +{
    + return down_write_trylock(&mm->mmap_sem) != 0;
    +}
    +
    +static inline void mmap_write_unlock(struct mm_struct *mm)
    +{
    + up_write(&mm->mmap_sem);
    +}
    +
    +static inline void mmap_downgrade_write_lock(struct mm_struct *mm)
    +{
    + downgrade_write(&mm->mmap_sem);
    +}
    +
    +static inline void mmap_read_lock(struct mm_struct *mm)
    +{
    + down_read(&mm->mmap_sem);
    +}
    +
    +static inline int mmap_read_lock_killable(struct mm_struct *mm)
    +{
    + return down_read_killable(&mm->mmap_sem);
    +}
    +
    +static inline bool mmap_read_trylock(struct mm_struct *mm)
    +{
    + return down_read_trylock(&mm->mmap_sem) != 0;
    +}
    +
    +static inline void mmap_read_unlock(struct mm_struct *mm)
    +{
    + up_read(&mm->mmap_sem);
    +}
    +
    +static inline bool mmap_is_locked(struct mm_struct *mm)
    +{
    + return rwsem_is_locked(&mm->mmap_sem) != 0;
    +}
    +
    +#endif /* _LINUX_MMAP_LOCK_H */
    --
    2.26.0.rc2.310.g2932bb562d-goog
    \
     
     \ /
      Last update: 2020-03-27 03:12    [W:6.614 / U:0.000 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site