| Message ID | 20230806231611.1395735-1-mjguzik@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: move dummy_vm_ops out of a header | expand |
On Mon, Aug 07, 2023 at 01:16:11AM +0200, Mateusz Guzik wrote: > Otherwise the kernel ends up with multiple copies: > $ nm vmlinux | grep dummy_vm_ops > ffffffff81e4ea00 d dummy_vm_ops.2 > ffffffff81e11760 d dummy_vm_ops.254 > ffffffff81e406e0 d dummy_vm_ops.4 > ffffffff81e3c780 d dummy_vm_ops.7 > > While here prefix it with vma_. It really shouldn't be prefixed with vma. Other than that, I love this patch. > [if someone has better ideas where to put it, please move it] > > Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> > --- > include/linux/mm.h | 6 +++--- > mm/init-mm.c | 2 ++ > 2 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 406ab9ea818f..14898e76bbf1 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -756,17 +756,17 @@ static inline void vma_mark_detached(struct vm_area_struct *vma, > > #endif /* CONFIG_PER_VMA_LOCK */ > > +extern const struct vm_operations_struct vma_dummy_vm_ops; > + > /* > * WARNING: vma_init does not initialize vma->vm_lock. > * Use vm_area_alloc()/vm_area_free() if vma needs locking. > */ > static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) > { > - static const struct vm_operations_struct dummy_vm_ops = {}; > - > memset(vma, 0, sizeof(*vma)); > vma->vm_mm = mm; > - vma->vm_ops = &dummy_vm_ops; > + vma->vm_ops = &vma_dummy_vm_ops; > INIT_LIST_HEAD(&vma->anon_vma_chain); > vma_mark_detached(vma, false); > vma_numab_state_init(vma); > diff --git a/mm/init-mm.c b/mm/init-mm.c > index efa97b57acfd..cfd367822cdd 100644 > --- a/mm/init-mm.c > +++ b/mm/init-mm.c > @@ -17,6 +17,8 @@ > #define INIT_MM_CONTEXT(name) > #endif > > +const struct vm_operations_struct vma_dummy_vm_ops; > + > /* > * For dynamically allocated mm_structs, there is a dynamically sized cpumask > * at the end of the structure, the size of which depends on the maximum CPU > -- > 2.39.2 > >
On 8/7/23, Matthew Wilcox <willy@infradead.org> wrote: > On Mon, Aug 07, 2023 at 01:16:11AM +0200, Mateusz Guzik wrote: >> Otherwise the kernel ends up with multiple copies: >> $ nm vmlinux | grep dummy_vm_ops >> ffffffff81e4ea00 d dummy_vm_ops.2 >> ffffffff81e11760 d dummy_vm_ops.254 >> ffffffff81e406e0 d dummy_vm_ops.4 >> ffffffff81e3c780 d dummy_vm_ops.7 >> >> While here prefix it with vma_. > > It really shouldn't be prefixed with vma. Other than that, I love this > patch. > I think an unprefixed global is iffy, but I'm not going to insist on semi-cosmetics. The one thing I expected people to complain about is the location of the struct. The mm_init.c file was the least bad choice I found, but maybe something else is preferred? I'm just trying to avoid sending V3 for this patch after someone claims dummy ops should land elsewhere. ;)
diff --git a/include/linux/mm.h b/include/linux/mm.h index 406ab9ea818f..14898e76bbf1 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -756,17 +756,17 @@ static inline void vma_mark_detached(struct vm_area_struct *vma, #endif /* CONFIG_PER_VMA_LOCK */ +extern const struct vm_operations_struct vma_dummy_vm_ops; + /* * WARNING: vma_init does not initialize vma->vm_lock. * Use vm_area_alloc()/vm_area_free() if vma needs locking. */ static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) { - static const struct vm_operations_struct dummy_vm_ops = {}; - memset(vma, 0, sizeof(*vma)); vma->vm_mm = mm; - vma->vm_ops = &dummy_vm_ops; + vma->vm_ops = &vma_dummy_vm_ops; INIT_LIST_HEAD(&vma->anon_vma_chain); vma_mark_detached(vma, false); vma_numab_state_init(vma); diff --git a/mm/init-mm.c b/mm/init-mm.c index efa97b57acfd..cfd367822cdd 100644 --- a/mm/init-mm.c +++ b/mm/init-mm.c @@ -17,6 +17,8 @@ #define INIT_MM_CONTEXT(name) #endif +const struct vm_operations_struct vma_dummy_vm_ops; + /* * For dynamically allocated mm_structs, there is a dynamically sized cpumask * at the end of the structure, the size of which depends on the maximum CPU
Otherwise the kernel ends up with multiple copies: $ nm vmlinux | grep dummy_vm_ops ffffffff81e4ea00 d dummy_vm_ops.2 ffffffff81e11760 d dummy_vm_ops.254 ffffffff81e406e0 d dummy_vm_ops.4 ffffffff81e3c780 d dummy_vm_ops.7 While here prefix it with vma_. [if someone has better ideas where to put it, please move it] Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> --- include/linux/mm.h | 6 +++--- mm/init-mm.c | 2 ++ 2 files changed, 5 insertions(+), 3 deletions(-)