Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 90794bf1 authored by Andrea Arcangeli's avatar Andrea Arcangeli Committed by Linus Torvalds
Browse files

userfaultfd: non-cooperative: optimize mremap_userfaultfd_complete() 

Optimize the mremap_userfaultfd_complete() interface to pass only the
vm_userfaultfd_ctx pointer through the stack as a microoptimization.

Link: http://lkml.kernel.org/r/20161216144821.5183-13-aarcange@redhat.com


Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Reported-by: default avatarHillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: default avatarMike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Michael Rapoport <RAPOPORT@il.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 72f87654

fs/userfaultfd.c

+2 −2
Original line number Diff line number Diff line
@@ -608,11 +608,11 @@ void mremap_userfaultfd_prep(struct vm_area_struct *vma, 
	}

}



void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx vm_ctx,

void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *vm_ctx,

				 unsigned long from, unsigned long to,

				 unsigned long len)

{

	struct userfaultfd_ctx *ctx = vm_ctx.ctx;

	struct userfaultfd_ctx *ctx = vm_ctx->ctx;

	struct userfaultfd_wait_queue ewq;



	if (!ctx)

include/linux/userfaultfd_k.h

+2 −2
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ extern void dup_userfaultfd_complete(struct list_head *); 


extern void mremap_userfaultfd_prep(struct vm_area_struct *,

				    struct vm_userfaultfd_ctx *);

extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx,

extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *,

					unsigned long from, unsigned long to,

					unsigned long len);
@@ -100,7 +100,7 @@ static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma, 
{

}



static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx ctx,

static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx,

					       unsigned long from,

					       unsigned long to,

					       unsigned long len)

mm/mremap.c

+1 −1
Original line number Diff line number Diff line
@@ -608,6 +608,6 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, 
	up_write(&current->mm->mmap_sem);

	if (locked && new_len > old_len)

		mm_populate(new_addr + old_len, new_len - old_len);

	mremap_userfaultfd_complete(uf, addr, new_addr, old_len);

	mremap_userfaultfd_complete(&uf, addr, new_addr, old_len);

	return ret;

}