[PATCH v2 2/2] m2p_find_override: use list_for_each_entry_safe

From: Stefano Stabellini
Date: Thu Mar 29 2012 - 10:03:23 EST


Use list_for_each_entry_safe and remove the spin_lock acquisition in
m2p_find_override: getting stale entries is OK because we should never
get an m2p_find_override call looking for an entry that we are about to
add or delete.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
arch/x86/xen/p2m.c | 9 ++-------
1 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 1b267e7..a4d35d4 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -807,23 +807,18 @@ EXPORT_SYMBOL_GPL(m2p_remove_override);

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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