Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [PATCH] Create initial stack independent of PAGE_SIZE | Date | Fri, 12 Feb 2010 16:20:40 +0900 (JST) |
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> Currently we create the initial stack based on the PAGE_SIZE. This is > unnecessary.
I don't think this is enough explanation. In past mail, you described why page size dependency is harmful. I hope you add it into the patch description.
IOW, we don't need to change the unnecessary-but-non-harmful behavior.
> > This creates this initial stack independent of the PAGE_SIZE. > > It also bumps up the number of 4k pages allocated from 20 to 32, to > align with 64K page systems.
Why do we need page-aligning? Do you mean this code doesn't works on 128K (or more larger) page systems?
> > Signed-off-by: Michael Neuling <mikey@neuling.org> > --- > This is the second half of my original patch. This can be targeted for > 2.6.34 as it's just a cleanup. > > Tested on PPC64 with 4k and 64k pages. > > fs/exec.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > Index: linux-2.6-ozlabs/fs/exec.c > =================================================================== > --- linux-2.6-ozlabs.orig/fs/exec.c > +++ linux-2.6-ozlabs/fs/exec.c > @@ -554,8 +554,6 @@ static int shift_arg_pages(struct vm_are > return 0; > } > > -#define EXTRA_STACK_VM_PAGES 20 /* random */ > - > /* > * Finalizes the stack vm_area_struct. The flags and permissions are updated, > * the stack is optionally relocated, and some extra space is added. > @@ -630,7 +628,7 @@ int setup_arg_pages(struct linux_binprm > goto out_unlock; > } > > - stack_expand = EXTRA_STACK_VM_PAGES * PAGE_SIZE; > + stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ > stack_size = vma->vm_end - vma->vm_start; > /* > * Align this down to a page boundary as expand_stack
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