linux-kernel - [PATCH] x86/xen: Free bootmem in free_p2m

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Message-Id: <1420639734-24808-1-git-send-email-boris.ostrovsky@oracle.com>
Date:	Wed,  7 Jan 2015 09:08:54 -0500
From:	Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:	david.vrabel@...rix.com, konrad.wilk@...cle.com, jgross@...e.com
Cc:	xen-devel@...ts.xenproject.org, linux-kernel@...r.kernel.org,
	boris.ostrovsky@...cle.com
Subject: [PATCH] x86/xen: Free bootmem in free_p2m_page() during early boot

With recent changes in p2m we now have legitimate cases when
p2m memory needs to be freed during early boot (i.e. before
slab is initialized).

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>
---
 arch/x86/xen/p2m.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index edbc7a6..df8acb4 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -167,10 +167,13 @@ static void * __ref alloc_p2m_page(void)
 	return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT);
 }
 
-/* Only to be called in case of a race for a page just allocated! */
 static void free_p2m_page(void *p)
 {
-	BUG_ON(!slab_is_available());
+	if (unlikely(!slab_is_available())) {
+		free_bootmem((unsigned long)p, PAGE_SIZE);
+		return;
+	}
+
 	free_page((unsigned long)p);
 }
 
-- 
1.9.3

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