45 lines
1.5 KiB
Diff
45 lines
1.5 KiB
Diff
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Subject: xenpaging: optimize p2m_mem_paging_populate
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p2m_mem_paging_populate will always put another request in the ring. To
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reduce pressure on the ring, place only required requests in the ring.
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If the gfn was already processed by another thread, and the current vcpu
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does not need to be paused, p2m_mem_paging_resume will do nothing with
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the request. And also xenpaging will drop the request if the vcpu does
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not need a wakeup.
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Signed-off-by: Olaf Hering <olaf@aepfle.de>
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---
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xen/arch/x86/mm/p2m.c | 9 +++++++--
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1 file changed, 7 insertions(+), 2 deletions(-)
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--- xen-4.0.1-testing.orig/xen/arch/x86/mm/p2m.c
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+++ xen-4.0.1-testing/xen/arch/x86/mm/p2m.c
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@@ -2571,12 +2571,12 @@ void p2m_mem_paging_populate(struct doma
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mem_event_request_t req;
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p2m_type_t p2mt;
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- memset(&req, 0, sizeof(req));
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-
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/* Check that there's space on the ring for this request */
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if ( mem_event_check_ring(d) )
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return;
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+ memset(&req, 0, sizeof(req));
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+
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/* Fix p2m mapping */
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/* XXX: It seems inefficient to have this here, as it's only needed
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* in one case (ept guest accessing paging out page) */
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@@ -2594,6 +2594,11 @@ void p2m_mem_paging_populate(struct doma
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vcpu_pause_nosync(v);
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req.flags |= MEM_EVENT_FLAG_VCPU_PAUSED;
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}
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+ else if ( p2mt != p2m_ram_paging_out && p2mt != p2m_ram_paged )
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+ {
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+ /* gfn is already on its way back and vcpu is not paused */
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+ return;
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+ }
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/* Send request to pager */
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req.gfn = gfn;
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