On Tue, Jan 30, 2024 at 06:50:48PM +0000, Lorenzo Stoakes wrote:
> On Wed, Jan 24, 2024 at 07:09:20PM +0100, Uladzislau Rezki (Sony) wrote:
> > This patch tends to simplify the function in question,
> > by removing an extra stack "objp" variable, returning
> > back to an early exit approach if spin_trylock() fails
> > or VA was not found.
> >
> > Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
> > ---
> > mm/vmalloc.c | 33 +++++++++++++++++----------------
> > 1 file changed, 17 insertions(+), 16 deletions(-)
> >
> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> > index b8be601b056d..449f45b0e474 100644
> > --- a/mm/vmalloc.c
> > +++ b/mm/vmalloc.c
> > @@ -4696,34 +4696,35 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
> > #ifdef CONFIG_PRINTK
> > bool vmalloc_dump_obj(void *object)
> > {
> > - void *objp = (void *)PAGE_ALIGN((unsigned long)object);
> > const void *caller;
> > + struct vm_struct *vm;
> > struct vmap_area *va;
> > struct vmap_node *vn;
> > unsigned long addr;
> > unsigned int nr_pages;
> > - bool success = false;
> > -
> > - vn = addr_to_node((unsigned long)objp);
> >
> > - if (spin_trylock(&vn->busy.lock)) {
> > - va = __find_vmap_area((unsigned long)objp, &vn->busy.root);
> > + addr = PAGE_ALIGN((unsigned long) object);
> > + vn = addr_to_node(addr);
> >
> > - if (va && va->vm) {
> > - addr = (unsigned long)va->vm->addr;
> > - caller = va->vm->caller;
> > - nr_pages = va->vm->nr_pages;
> > - success = true;
> > - }
> > + if (!spin_trylock(&vn->busy.lock))
> > + return false;
> >
> > + va = __find_vmap_area(addr, &vn->busy.root);
> > + if (!va || !va->vm) {
> > spin_unlock(&vn->busy.lock);
> > + return false;
> > }
> >
> > - if (success)
> > - pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
> > - nr_pages, addr, caller);
> > + vm = va->vm;
> > + addr = (unsigned long) vm->addr;
>
> Hmm not so nice to reuse addr here for something different, might be nice
> to have separate obj_addr and vm_addr or something. But it's not critical!
>
> > + caller = vm->caller;
> > + nr_pages = vm->nr_pages;
> > + spin_unlock(&vn->busy.lock);
> >
> > - return success;
> > + pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
> > + nr_pages, addr, caller);
> > +
> > + return true;
> > }
> > #endif
> >
> > --
> > 2.39.2
> >
>
> Other than the nit, which I don't insist on, this is a big improvement so,
>
> Reviewed-by: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
>
Thanks!
--
Uladzislau Rezki
