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Re: [Qemu-devel] [Bug 1826393] [NEW] QEMU 3.1.0 stuck waiting for 800ms
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From: |
Stefan Hajnoczi |
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Subject: |
Re: [Qemu-devel] [Bug 1826393] [NEW] QEMU 3.1.0 stuck waiting for 800ms (5 times slower) in pre-bios phase |
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Date: |
Mon, 29 Apr 2019 11:47:33 -0400 |
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User-agent: |
Mutt/1.11.3 (2019-02-01) |
On Thu, Apr 25, 2019 at 11:37:02AM -0000, Waldemar Kozaczuk wrote:
> Public bug reported:
>
> Yesterday I have upgraded my laptop from Ubuntu 18.10 to 19.04 and that
> way got newer QEMU 3.1.0 along vs QEMU 2.12.0 before. I have noticed
> that everytime I start QEMU to run OSv, QEMU seems to hand noticably
> longer (~1 second) before showing SeaBIOS output. I have tried all kind
> of combinations to get rid of that pause and nothing helped.
>
> Here is my start command:
> time qemu-system-x86_64 -m 256M -smp 1 -nographic -nodefaults \
> -device virtio-blk-pci,id=blk0,bootindex=0,drive=hd0,scsi=off \
> -drive file=usr.img,if=none,id=hd0,cache=none,aio=thre\
> -enable-kvm \
> -cpu host,+x2apic -chardev stdio,mux=on,id=stdio,signal=off \
> -mon chardev=stdio,mode=readline -device isa-serial,chardev=stdio
>
> It looks like qemu process starts, waits almost a second for something
> and then print SeaBIOS splashscreen and continues boot:
>
> --> waits here
> SeaBIOS (version 1.12.0-1)
> Booting from Hard Disk..OSv v0.53.0-6-gc8395118
> disk read (real mode): 27.25ms, (+27.25ms)
> uncompress lzloader.elf: 46.22ms, (+18.97ms)
> TLS initialization: 46.79ms, (+0.57ms)
> .init functions: 47.82ms, (+1.03ms)
> SMP launched: 48.08ms, (+0.26ms)
> VFS initialized: 49.25ms, (+1.17ms)
> Network initialized: 49.48ms, (+0.24ms)
> pvpanic done: 49.57ms, (+0.08ms)
> pci enumerated: 52.42ms, (+2.85ms)
> drivers probe: 52.42ms, (+0.00ms)
> drivers loaded: 55.33ms, (+2.90ms)
> ROFS mounted: 56.37ms, (+1.04ms)
> Total time: 56.37ms, (+0.00ms)
> Found optarg
> dev etc hello libenviron.so libvdso.so proc tmp tools usr
>
> real 0m0.935s
> user 0m0.426s
> sys 0m0.490s
>
> With version 2.12.0 I used to see real below 200ms. So it seems qemu
> slowed down 5 times.
>
> I ran strace -tt against it and I have noticed a pause here:
> ...
> 07:31:41.848579 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 0
> 07:31:41.848604 futex(0x55c4a2ff6308, FUTEX_WAIT_PRIVATE, 0, NULL) = 0
> 07:31:41.848649 ioctl(10, KVM_SET_PIT2, 0x7ffdd272d1f0) = 0
> 07:31:41.848674 ioctl(9, KVM_CHECK_EXTENSION, KVM_CAP_KVMCLOCK_CTRL) = 1
> 07:31:41.848699 ioctl(10, KVM_SET_CLOCK, 0x7ffdd272d230) = 0
> 07:31:41.848724 futex(0x55c4a49a9a9c, FUTEX_WAKE_PRIVATE, 2147483647) = 1
> 07:31:41.848747 getpid() = 5162
> 07:31:41.848769 tgkill(5162, 5166, SIGUSR1) = 0
> 07:31:41.848791 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 0
> 07:31:41.848814 futex(0x55c4a49a9a98, FUTEX_WAKE_PRIVATE, 2147483647) = 1
> 07:31:41.848837 getpid() = 5162
> 07:31:41.848858 tgkill(5162, 5166, SIGUSR1) = 0
> 07:31:41.848889 write(8, "\1\0\0\0\0\0\0\0", 8) = 8
> 07:31:41.848919 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 1
> 07:31:41.848943 ppoll([{fd=0, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5,
> events=POLLIN}, {fd=7, events=POLLIN},
> {fd=8, events=POLLIN}], 5, {tv_sec=0, tv_nsec=0}, NULL, 8) = 1 ([{fd=8,
> revents=POLLIN}], left {tv_sec=0, tv_nsec=0
> })
> 07:31:41.849003 futex(0x55c4a2fd34c0, FUTEX_WAIT_PRIVATE, 2, NULL) = -1
> EAGAIN (Resource temporarily unavailable)
> 07:31:41.849031 read(8, "\5\0\0\0\0\0\0\0", 16) = 8
> 07:31:41.849064 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 0
> 07:31:41.849086 ppoll([{fd=0, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5,
> events=POLLIN}, {fd=7, events=POLLIN},
> {fd=8, events=POLLIN}], 5, {tv_sec=0, tv_nsec=984624000}, NULL, 8) = 1
> ([{fd=7, revents=POLLIN}], left {tv_sec=0, t
> v_nsec=190532609})
>
> --> waits for almost 800ms
>
> 07:31:42.643272 futex(0x55c4a2fd34c0, FUTEX_WAIT_PRIVATE, 2, NULL) = 0
> 07:31:42.643522 read(7, "\1\0\0\0\0\0\0\0", 512) = 8
> 07:31:42.643625 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 1
> 07:31:42.643646 ppoll([{fd=0, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5,
> events=POLLIN}, {fd=7, events=POLLIN},
> {fd=8, events=POLLIN}], 5, {tv_sec=0, tv_nsec=190066000}, NULL, 8) = 2
> ([{fd=4, revents=POLLIN}, {fd=8, revents=POL
> LIN}], left {tv_sec=0, tv_nsec=189909632})
> 07:31:42.643836 futex(0x55c4a2fd34c0, FUTEX_WAIT_PRIVATE, 2, NULL) = -1
> EAGAIN (Resource temporarily unavailable)
> 07:31:42.643859 read(8, "\2\0\0\0\0\0\0\0", 16) = 8
> 07:31:42.643880 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 1
>
> ...
>
> when I run same command using qemu 3.0.5 that I still happen to have on
> the same machine that I built directly from source I see total boot time
> at around 200ms. It seems like a regression.
Please try building QEMU 4.0.0 from source:
https://download.qemu.org/qemu-4.0.0.tar.xz
> ** Affects: qemu
> Importance: Undecided
> Status: New
>
> --
> You received this bug notification because you are a member of qemu-
> devel-ml, which is subscribed to QEMU.
> https://bugs.launchpad.net/bugs/1826393
>
> Title:
> QEMU 3.1.0 stuck waiting for 800ms (5 times slower) in pre-bios phase
>
> Status in QEMU:
> New
>
> Bug description:
> Yesterday I have upgraded my laptop from Ubuntu 18.10 to 19.04 and
> that way got newer QEMU 3.1.0 along vs QEMU 2.12.0 before. I have
> noticed that everytime I start QEMU to run OSv, QEMU seems to hand
> noticably longer (~1 second) before showing SeaBIOS output. I have
> tried all kind of combinations to get rid of that pause and nothing
> helped.
>
> Here is my start command:
> time qemu-system-x86_64 -m 256M -smp 1 -nographic -nodefaults \
> -device virtio-blk-pci,id=blk0,bootindex=0,drive=hd0,scsi=off \
> -drive file=usr.img,if=none,id=hd0,cache=none,aio=thre\
> -enable-kvm \
> -cpu host,+x2apic -chardev stdio,mux=on,id=stdio,signal=off \
> -mon chardev=stdio,mode=readline -device isa-serial,chardev=stdio
>
> It looks like qemu process starts, waits almost a second for something
> and then print SeaBIOS splashscreen and continues boot:
>
> --> waits here
> SeaBIOS (version 1.12.0-1)
> Booting from Hard Disk..OSv v0.53.0-6-gc8395118
> disk read (real mode): 27.25ms, (+27.25ms)
> uncompress lzloader.elf: 46.22ms, (+18.97ms)
> TLS initialization: 46.79ms, (+0.57ms)
> .init functions: 47.82ms, (+1.03ms)
> SMP launched: 48.08ms, (+0.26ms)
> VFS initialized: 49.25ms, (+1.17ms)
> Network initialized: 49.48ms, (+0.24ms)
> pvpanic done: 49.57ms, (+0.08ms)
> pci enumerated: 52.42ms, (+2.85ms)
> drivers probe: 52.42ms, (+0.00ms)
> drivers loaded: 55.33ms, (+2.90ms)
> ROFS mounted: 56.37ms, (+1.04ms)
> Total time: 56.37ms, (+0.00ms)
> Found optarg
> dev etc hello libenviron.so libvdso.so proc tmp tools usr
>
> real 0m0.935s
> user 0m0.426s
> sys 0m0.490s
>
> With version 2.12.0 I used to see real below 200ms. So it seems qemu
> slowed down 5 times.
>
> I ran strace -tt against it and I have noticed a pause here:
> ...
> 07:31:41.848579 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 0
> 07:31:41.848604 futex(0x55c4a2ff6308, FUTEX_WAIT_PRIVATE, 0, NULL) = 0
> 07:31:41.848649 ioctl(10, KVM_SET_PIT2, 0x7ffdd272d1f0) = 0
> 07:31:41.848674 ioctl(9, KVM_CHECK_EXTENSION, KVM_CAP_KVMCLOCK_CTRL) = 1
> 07:31:41.848699 ioctl(10, KVM_SET_CLOCK, 0x7ffdd272d230) = 0
> 07:31:41.848724 futex(0x55c4a49a9a9c, FUTEX_WAKE_PRIVATE, 2147483647) = 1
> 07:31:41.848747 getpid() = 5162
> 07:31:41.848769 tgkill(5162, 5166, SIGUSR1) = 0
> 07:31:41.848791 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 0
> 07:31:41.848814 futex(0x55c4a49a9a98, FUTEX_WAKE_PRIVATE, 2147483647) = 1
> 07:31:41.848837 getpid() = 5162
> 07:31:41.848858 tgkill(5162, 5166, SIGUSR1) = 0
> 07:31:41.848889 write(8, "\1\0\0\0\0\0\0\0", 8) = 8
> 07:31:41.848919 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 1
> 07:31:41.848943 ppoll([{fd=0, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5,
> events=POLLIN}, {fd=7, events=POLLIN},
> {fd=8, events=POLLIN}], 5, {tv_sec=0, tv_nsec=0}, NULL, 8) = 1 ([{fd=8,
> revents=POLLIN}], left {tv_sec=0, tv_nsec=0
> })
> 07:31:41.849003 futex(0x55c4a2fd34c0, FUTEX_WAIT_PRIVATE, 2, NULL) = -1
> EAGAIN (Resource temporarily unavailable)
> 07:31:41.849031 read(8, "\5\0\0\0\0\0\0\0", 16) = 8
> 07:31:41.849064 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 0
> 07:31:41.849086 ppoll([{fd=0, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5,
> events=POLLIN}, {fd=7, events=POLLIN},
> {fd=8, events=POLLIN}], 5, {tv_sec=0, tv_nsec=984624000}, NULL, 8) = 1
> ([{fd=7, revents=POLLIN}], left {tv_sec=0, t
> v_nsec=190532609})
>
> --> waits for almost 800ms
>
> 07:31:42.643272 futex(0x55c4a2fd34c0, FUTEX_WAIT_PRIVATE, 2, NULL) = 0
> 07:31:42.643522 read(7, "\1\0\0\0\0\0\0\0", 512) = 8
> 07:31:42.643625 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 1
> 07:31:42.643646 ppoll([{fd=0, events=POLLIN}, {fd=4, events=POLLIN}, {fd=5,
> events=POLLIN}, {fd=7, events=POLLIN},
> {fd=8, events=POLLIN}], 5, {tv_sec=0, tv_nsec=190066000}, NULL, 8) = 2
> ([{fd=4, revents=POLLIN}, {fd=8, revents=POL
> LIN}], left {tv_sec=0, tv_nsec=189909632})
> 07:31:42.643836 futex(0x55c4a2fd34c0, FUTEX_WAIT_PRIVATE, 2, NULL) = -1
> EAGAIN (Resource temporarily unavailable)
> 07:31:42.643859 read(8, "\2\0\0\0\0\0\0\0", 16) = 8
> 07:31:42.643880 futex(0x55c4a2fd34c0, FUTEX_WAKE_PRIVATE, 1) = 1
>
> ...
>
> when I run same command using qemu 3.0.5 that I still happen to have
> on the same machine that I built directly from source I see total boot
> time at around 200ms. It seems like a regression.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/qemu/+bug/1826393/+subscriptions
>
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