search for: test_all_events

In "Understanding the Linux Kernel" 3rd edition, section 4.7 "Softirqs and Tasklets" it states: "Activation and execution [of defferable functions] are bound together: a deferrable function that has been activated by a given CPU must be executed on the same CPU. There is no self-evident reason suggesting that this rule is beneficial for system performance. Binding the

...== --- 2007-08-08.orig/xen/arch/x86/x86_64/compat/entry.S 2007-06-22 16:57:45.000000000 +0200 +++ 2007-08-08/xen/arch/x86/x86_64/compat/entry.S 2007-08-08 11:37:08.000000000 +0200 @@ -187,6 +187,39 @@ ENTRY(compat_post_handle_exception) movb $0,TRAPBOUNCE_flags(%rdx) jmp compat_test_all_events +ENTRY(compat_syscall) + cmpb $0,VCPU_syscall32_disables_events(%rbx) + movzwl VCPU_syscall32_sel(%rbx),%esi + movq VCPU_syscall32_addr(%rbx),%rax + setne %cl + leaq VCPU_trap_bounce(%rbx),%rdx + testl $~3,%esi + leal (,%rcx,TBF_INTERRUPT),%ecx...

...symbol name 492796 20.0510 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 do_update_va_mapping 268506 10.9251 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 ptwr_do_page_fault 81074 3.2988 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 test_all_events 72424 2.9468 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 get_page_from_l1e 66056 2.6877 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 handle_exception 61031 2.4832 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 do_mmu_update Native, Worker:...

...symbol name 492796 20.0510 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 do_update_va_mapping 268506 10.9251 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 ptwr_do_page_fault 81074 3.2988 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 test_all_events 72424 2.9468 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 get_page_from_l1e 66056 2.6877 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 handle_exception 61031 2.4832 xen-syms-pae-3.0.4_13138-0.33 xen-syms-pae-3.0.4_13138-0.33 do_mmu_update Native, Worker:...

This set of patches converts the way frames gets created from using PUSHes/POPs to using MOVes, thus allowing (in certain cases) to avoid saving/restoring part of the register set. While the place where the (small) win from this comes from varies between CPUs, the net effect is a 1 to 2% reduction on a combined interruption entry and exit when the full state save can be avoided. 1: use MOV

The self_nmi() code cause''s an NMI to be triggered by sending an APIC message to the local processor. However, NMIs are blocked by the VMEXIT, until the next iret or VMENTER. Volume 3 Chapter 27 Section 1 of the Intel SDM states: An NMI causes subsequent NMIs to be blocked, but only after the VM exit completes. As a result, as soon as the VMENTER happens, an immediate VMEXIT happens

(The list appears to have eaten my previous attempt to send this. Apologies if you receive multiple copies.) The attached patches allow you to use paravirtualised network and block interfaces from fully virtualised domains, based on Intel''s patches from a few months ago. These are significantly faster than the equivalent ioemu devices, sometimes by more than an order of magnitude.