Messages in this thread | | | Date | Wed, 20 Jun 2012 14:29:39 +0200 | From | Anton Arapov <> | Subject | Re: [PATCH 5/5] uprobes: write_opcode: alloc the new page outside of "retry" loop |
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On Tue, Jun 19, 2012 at 09:47:59PM +0200, Oleg Nesterov wrote: > It is ugly to free and re-alloc new_page if write_opcode() needs to > retry. Move alloc_page_vma/page_cache_release outside of "retry" loop. > > Signed-off-by: Oleg Nesterov <oleg@redhat.com> > --- > kernel/events/uprobes.c | 26 +++++++++++--------------- > 1 files changed, 11 insertions(+), 15 deletions(-) > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > index 442064d..3fd7bdf 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -214,19 +214,18 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, > struct vm_area_struct *vma; > int ret; > > -retry: > - /* Read the page with vaddr into memory */ > - ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma); > - if (ret <= 0) > - return ret; > - > - ret = -ENOMEM; > new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr); Should we want NULL instead of vma in alloc_page_vma()? Or initialize vma with NULL...
> if (!new_page) > - goto put_old; > + return -ENOMEM; > > __SetPageUptodate(new_page); > > + retry: > + /* Read the page with vaddr into memory */ > + ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma); > + if (ret <= 0) > + goto out; > + [cut]
Anton.
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