﻿ticket	summary	version	guest	type	created	modified	_changetime	_description	_reporter
15557	Solaris + SMP: Performance decreases as you add processors to guest	VirtualBox 5.0.22	Windows	defect	2016-06-29T14:24:59Z	2016-09-22T21:16:05Z	2016-09-22T21:16:05Z	"I found that with VirtualBox 5.0.x, when you have 1-2 processors assigned to a VM, performance is quite fast. But the more processors you add, the slower the guest VM becomes. I've gone up to 16 processors, which is very slow to boot and extremely laggy after logging in (even Task Manager stopped responding.)

For a scientific test, I used the same host and guest, with a combination of vbox versions and processors assigned to the guest.

The host:
- O/S: Solaris 11.2.15.4.0
- Hardware: Oracle X4-2L
- CPUs: Quantity 2 of E5-2690 v2, 10 cores, 20 threads (Total of 20 cores, 40 threads)
- RAM: 512GB

The guest:
- O/S: Windows 7 + IE 9 Developer VM, downloaded from https://developer.microsoft.com/en-us/m ... tools/vms/
- RAM: 4GB
- Video RAM: 64MB

Below are the timings for how long it takes to boot the guest VM (complete when you see the start button):

VirtualBox 4.3.32:
        - 4 CPU: 0:24
        - 10 CPU: 0:30
        - 16 CPU: 1:06
VirtualBox 4.3.38:
        - 4 CPU: 0:23
        - 10 CPU: 0:30
        - 16 CPU: 0:48
VirtualBox 5.0.4:
        - 4 CPU: 0:22
        - 10 CPU: 1:44
        - 16 CPU: 3:36
VirtualBox 5.0.22:
        - 4 CPU: 0:21
        - 10 CPU: 1:40
        - 16 CPU: 4:15

I'm not 100% sure that this is the cause of the issue. But, by doing ""truss"", ""pstack"" and ""pfiles"" commands, I found that several stack traces that are performing a tremendous amount of ioctl() system calls against the /dev/vboxdrv device. Here are some of the stack traces:

Stack Trace 1:

{{{
     ffff80ffbf51edba ioctl    (13, ffffffffc0185687, ffff80ffbe13ddc0)
     ffff80ffa385df0f SUPR3CallVMMR0Ex () + 30f
     ffff80ffa0accad3 _Z19vmR3HaltGlobal1HaltP6UVMCPUjm () + 1e3
     ffff80ffa0acd004 VMR3WaitHalted () + f4
     ffff80ffa0a62d66 EMR3ExecuteVM () + 656
     ffff80ffa0acbbcf _Z25vmR3EmulationThreadWithIdP11RTTHREADINTP6UVMCPUj () + 12f
     ffff80ffa37d8aac rtThreadMain () + 2c
     ffff80ffa38557c1 _Z18rtThreadNativeMainPv () + 51
     ffff80ffbf515ef5 _thrp_setup () + a5
     ffff80ffbf5161a0 _lwp_start ()
}}}


Stack Trace 2:

{{{
     ffff80ffbf51edba ioctl    (13, ffffffffc0185698, ffff80ffbcbceda0)
     ffff80ffa3862442 SUPSemEventWaitNoResume () + 82
     ffff80ff9fd3d440 _Z15ahciAsyncIOLoopP9PDMDEVINSP9PDMTHREAD () + 330
     ffff80ffa0a87aea _Z15pdmR3ThreadMainP11RTTHREADINTPv () + 6a
     ffff80ffa37d8aac rtThreadMain () + 2c
     ffff80ffa38557c1 _Z18rtThreadNativeMainPv () + 51
     ffff80ffbf515ef5 _thrp_setup () + a5
     ffff80ffbf5161a0 _lwp_start ()
}}}


Stack Trace 3:

{{{
     ffff80ffbf51edba ioctl    (13, ffffffffc0185698, ffff80ffbc2fcc60)
     ffff80ffa3862442 SUPSemEventWaitNoResume () + 82
     ffff80ffa0b45828 _Z29pdmR3R0CritSectEnterContendedP11PDMCRITSECTmPK15RTLOCKVALSRCPOS () + 98
     ffff80ffa0b45914 PDMCritSectEnter () + a4
     ffff80ffa0a98424 PGMR3PhysReadExternal () + 34
     ffff80ffa0a7a4e8 _Z20pdmR3DevHlp_PhysReadP9PDMDEVINSmPvm () + 78
     ffff80ff9fd0b4f4 _Z17ohciR3ThreadFrameP9PDMDEVINSP9PDMTHREAD () + 254
     ffff80ffa0a87aea _Z15pdmR3ThreadMainP11RTTHREADINTPv () + 6a
     ffff80ffa37d8aac rtThreadMain () + 2c
     ffff80ffa38557c1 _Z18rtThreadNativeMainPv () + 51
     ffff80ffbf515ef5 _thrp_setup () + a5
     ffff80ffbf5161a0 _lwp_start ()
}}}

Currently, this issue prevents us from using 5.0.x at all."	KSJohn
16169	after restoring guest XP guest Bugcheck KERNEL_MODE_EXCEPTION_NOT_HANDLED_M (1000008e)	VirtualBox 5.1.8	Windows	defect	2016-11-08T17:34:50Z	2018-02-08T15:53:58Z	2018-02-08T15:53:58Z	"The guest runs fine, the problem only happens after restoring a saved state.
The Bluescreen appears only in VBox 5.1 (not in version 5.0) for me and only when AMD-V is enabled.

The CPU is AMD Phenom II X4 965[[BR]]
Host OS: Win7 x64[[BR]]
Guest OS: WinXP 32bit I/O APIC enabled / PAE setting has no effect[[BR]]

Here is the Bugcheck: KERNEL_MODE_EXCEPTION_NOT_HANDLED_M (1000008e)[[BR]]
EXCEPTION_CODE: (NTSTATUS) 0xc000001d - {EXCEPTION}  Illegal Instruction  An attempt was made to execute an illegal instruction.

Attached are two minidumps of the guest os. The crash is reproducible every time. Please let me know if you need any more information."	oracle_email_with_a_plus_sign
