lkml.org 
[lkml]   [2021]   [Aug]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 1/3] vmalloc: Choose a better start address in vm_area_register_early()
On Mon, Aug 09, 2021 at 05:37:48PM +0800, Kefeng Wang wrote:
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index d5cd52805149..1e8fe08725b8 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -2238,11 +2238,17 @@ void __init vm_area_add_early(struct vm_struct *vm)
> */
> void __init vm_area_register_early(struct vm_struct *vm, size_t align)
> {
> - static size_t vm_init_off __initdata;
> - unsigned long addr;
> -
> - addr = ALIGN(VMALLOC_START + vm_init_off, align);
> - vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
> + struct vm_struct *head = vmlist, *curr, *next;
> + unsigned long addr = ALIGN(VMALLOC_START, align);
> +
> + while (head != NULL) {

Nitpick: I'd use the same pattern as in vm_area_add_early(), i.e. a
'for' loop. You might as well insert it directly than calling the add
function and going through the loop again. Not a strong preference
either way.

> + next = head->next;
> + curr = head;
> + head = next;
> + addr = ALIGN((unsigned long)curr->addr + curr->size, align);
> + if (next && (unsigned long)next->addr - addr > vm->size)

Is greater or equal sufficient?

> + break;
> + }
>
> vm->addr = (void *)addr;

Another nitpick: it's very unlikely on a 64-bit architecture but not
impossible on 32-bit to hit VMALLOC_END here. Maybe some BUG_ON.

--
Catalin

\
 
 \ /
  Last update: 2021-08-25 20:00    [W:0.142 / U:0.544 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site