Messages in this thread Patch in this message | | | From | Konrad Rzeszutek Wilk <> | Subject | [PATCH 04/11] xen/mmu: BUG_ON when racing to swap middle leaf. | Date | Mon, 31 Jan 2011 17:44:29 -0500 |
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The initial bootup code uses set_phys_to_machine quite a lot, and after bootup it would be used by the balloon driver. The balloon driver does have mutex lock so this should not be necessary - but just in case, add a BUG_ON if we do hit this scenario.
[v2: Change from WARN to BUG_ON] [v3: Rebased on top of xen->p2m code split] Reviewed-by: Ian Campbell <Ian.Campbell@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- arch/x86/xen/p2m.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 19b0a65..fbbd2ab 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -478,7 +478,8 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) /* Swap over from MISSING to IDENTITY if needed. */ if (p2m_top[topidx][mididx] == p2m_missing) { - p2m_top[topidx][mididx] = p2m_identity; + BUG_ON(cmpxchg(&p2m_top[topidx][mididx], p2m_missing, + p2m_identity) != p2m_missing); return true; } } -- 1.7.1
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