Re: [PATCH 2/2] m2p_find_override: use list_for_each_entry_safe
From: Konrad Rzeszutek Wilk
Date: Tue Mar 27 2012 - 10:43:38 EST
On Tue, Mar 27, 2012 at 02:52:44PM +0100, Stefano Stabellini wrote:
> Use list_for_each_entry_safe and remove the spin_lock acquisition in
> m2p_find_override.
So this would allow us to get stale entries. Is that OK?
>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> ---
> arch/x86/xen/p2m.c | 8 ++------
> 1 files changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
> index 1b267e7..7ed8cc3 100644
> --- a/arch/x86/xen/p2m.c
> +++ b/arch/x86/xen/p2m.c
> @@ -809,21 +809,17 @@ struct page *m2p_find_override(unsigned long mfn)
> {
> unsigned long flags;
> struct list_head *bucket = &m2p_overrides[mfn_hash(mfn)];
> - struct page *p, *ret;
> + struct page *p, *t, *ret;
>
> ret = NULL;
>
> - spin_lock_irqsave(&m2p_override_lock, flags);
> -
> - list_for_each_entry(p, bucket, lru) {
> + list_for_each_entry_safe(p, t, bucket, lru) {
> if (page_private(p) == mfn) {
> ret = p;
> break;
> }
> }
>
> - spin_unlock_irqrestore(&m2p_override_lock, flags);
> -
> return ret;
> }
>
> --
> 1.7.2.5
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