Messages in this thread | | | Subject | Re: [PATCH v5 01/10] mmap locking API: initial implementation as rwsem wrappers | From | Laurent Dufour <> | Date | Mon, 18 May 2020 15:18:29 +0200 |
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Le 22/04/2020 à 02:14, Michel Lespinasse a écrit : > 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> > Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> > Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
> --- > include/linux/mm.h | 1 + > include/linux/mmap_lock.h | 54 +++++++++++++++++++++++++++++++++++++++ > 2 files changed, 55 insertions(+) > create mode 100644 include/linux/mmap_lock.h > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 5a323422d783..051ec782bdbb 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..97ac53b66052 > --- /dev/null > +++ b/include/linux/mmap_lock.h > @@ -0,0 +1,54 @@ > +#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_write_downgrade(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); > +} > + > +#endif /* _LINUX_MMAP_LOCK_H */ >
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