Comments
Patch
@@ -1203,6 +1203,25 @@ unsigned long xen_read_cr2_direct(void)
return this_cpu_read(xen_vcpu_info.arch.cr2);
}
+void xen_flush_tlb_all(void)
+{
+ struct mmuext_op *op;
+ struct multicall_space mcs;
+
+ trace_xen_mmu_flush_tlb_all(0);
+
+ preempt_disable();
+
+ mcs = xen_mc_entry(sizeof(*op));
+
+ op = mcs.args;
+ op->cmd = MMUEXT_TLB_FLUSH_ALL;
+ MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+
+ preempt_enable();
+}
static void xen_flush_tlb(void)
{
struct mmuext_op *op;
@@ -2339,7 +2358,7 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
err = 0;
out:
- flush_tlb_all();
+ xen_flush_tlb_all();
return err;
}
@@ -377,6 +377,14 @@ DECLARE_EVENT_CLASS(xen_mmu_pgd,
DEFINE_XEN_MMU_PGD_EVENT(xen_mmu_pgd_pin);
DEFINE_XEN_MMU_PGD_EVENT(xen_mmu_pgd_unpin);
+TRACE_EVENT(xen_mmu_flush_tlb_all,
+ TP_PROTO(int x),
+ TP_ARGS(x),
+ TP_STRUCT__entry(__array(char, x, 0)),
+ TP_fast_assign((void)x),
+ TP_printk("%s", "")
+ );
+
TRACE_EVENT(xen_mmu_flush_tlb,
TP_PROTO(int x),
TP_ARGS(x),
This is a note to let you know that I have just added a patch titled xen/mmu: Use Xen specific TLB flush instead of the generic to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ From c02fa7a1de406dc520aef58e475ce89bccfe8bac Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Date: Wed, 31 Oct 2012 12:38:31 -0400 Subject: [PATCH] xen/mmu: Use Xen specific TLB flush instead of the generic one. X-Extended-Stable: 3.5 commit 95a7d76897c1e7243d4137037c66d15cbf2cce76 upstream. As Mukesh explained it, the MMUEXT_TLB_FLUSH_ALL allows the hypervisor to do a TLB flush on all active vCPUs. If instead we were using the generic one (which ends up being xen_flush_tlb) we end up making the MMUEXT_TLB_FLUSH_LOCAL hypercall. But before we make that hypercall the kernel will IPI all of the vCPUs (even those that were asleep from the hypervisor perspective). The end result is that we needlessly wake them up and do a TLB flush when we can just let the hypervisor do it correctly. This patch gives around 50% speed improvement when migrating idle guest's from one host to another. Oracle-bug: 14630170 Tested-by: Jingjie Jiang <jingjie.jiang@oracle.com> Suggested-by: Mukesh Rathor <mukesh.rathor@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- arch/x86/xen/mmu.c | 21 ++++++++++++++++++++- include/trace/events/xen.h | 8 ++++++++ 2 files changed, 28 insertions(+), 1 deletion(-) -- 1.7.9.5