Re: SCHED_4BSD bad interactivity on 7.0 vs 6.3
On Sun, 13 Jul 2008, Nate Eldredge wrote: On Sun, 13 Jul 2008, Kris Kennaway wrote: Nate Eldredge wrote: On Sun, 13 Jul 2008, Kris Kennaway wrote: Nate Eldredge wrote: Hi folks, Hopefully this is a good list for this topic. It seems like there has been a regression in interactivity from 6.3-RELEASE to 7.0-RELEASE when using the SCHED_4BSD scheduler. After upgrading my single-cpu amd64 box, 7.0 has much worse latency. When running a kernel compile, there is a noticeable lag to echo my typing or scroll my browser windows, and playing an mp3 frequently cuts out for a second or two. This did not happen on 6.3-RELEASE. Are you sure it's not the x.org server bug that was present in the version shipped with 7.0? Update to the latest version and see if your X interactivity improves. Yes, I had not yet upgraded my x.org port when testing this, so it was the same x.org that was fine under 6.3. Also: I wrote a small program which forks two processes that run gettimeofday() in a tight loop to see how long they get scheduled out. On 6.3 the maximum latency is usually under 100 ms. On 7.0 it is 500 ms or more even when nothing else is running on the system. When a compile is also running it is sometimes 1400 ms or more. This test shows a difference even in single user mode, when X is not running at all. It shows *a* difference, but perhaps not the *same* difference. Please humour me and rule it out. Okay. I am in the process of recompiling all my ports, so after that is done I will boot with a GENERIC kernel and see what happens. After trying this, I can't seem to reproduce the sound skipping behavior, unless I do something fairly extreme like "make -j 6". But the mouse does seem to skip when a compile is running, so I do believe there is a regression. -- Nate Eldredge [EMAIL PROTECTED] ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: SCHED_4BSD bad interactivity on 7.0 vs 6.3
On Sun, Jul 13, 2008 at 12:47 AM, Eugene Grosbein <[EMAIL PROTECTED]> wrote: > On Sun, Jul 13, 2008 at 03:11:23AM +0200, Kris Kennaway wrote: > >> >It seems like there has been a regression in interactivity from >> >6.3-RELEASE to 7.0-RELEASE when using the SCHED_4BSD scheduler. After >> >upgrading my single-cpu amd64 box, 7.0 has much worse latency. When >> >running a kernel compile, there is a noticeable lag to echo my typing or >> >scroll my browser windows, and playing an mp3 frequently cuts out for a >> >second or two. This did not happen on 6.3-RELEASE. >> >> Are you sure it's not the x.org server bug that was present in the >> version shipped with 7.0? > > No, it's not. I have exactly the same problem with SCHED_4BSD > after upgrade from 6.3-STABLE to 7.0-STABLE. I didn't upgrade > my x.org 6.9.0, only OS (all 6.x compat shims are installed). > There is some sort of regression, certainly. IIRC some folks reported performance degradation using SCHED_4BSD in the past after the SMP fixes, so this isn't a new news story. SCHED_ULE isn't going to be default until 7.1-RELEASE I believe because they might be fanning out a few bugs in -CURRENT (the number of bugs are small from what I've seen) and MFC'ing them to 7-RELEASE. -Garrett ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: SCHED_4BSD bad interactivity on 7.0 vs 6.3
On Sun, 13 Jul 2008, Kris Kennaway wrote: Nate Eldredge wrote: On Sun, 13 Jul 2008, Kris Kennaway wrote: Nate Eldredge wrote: Hi folks, Hopefully this is a good list for this topic. It seems like there has been a regression in interactivity from 6.3-RELEASE to 7.0-RELEASE when using the SCHED_4BSD scheduler. After upgrading my single-cpu amd64 box, 7.0 has much worse latency. When running a kernel compile, there is a noticeable lag to echo my typing or scroll my browser windows, and playing an mp3 frequently cuts out for a second or two. This did not happen on 6.3-RELEASE. Are you sure it's not the x.org server bug that was present in the version shipped with 7.0? Update to the latest version and see if your X interactivity improves. Yes, I had not yet upgraded my x.org port when testing this, so it was the same x.org that was fine under 6.3. Also: I wrote a small program which forks two processes that run gettimeofday() in a tight loop to see how long they get scheduled out. On 6.3 the maximum latency is usually under 100 ms. On 7.0 it is 500 ms or more even when nothing else is running on the system. When a compile is also running it is sometimes 1400 ms or more. This test shows a difference even in single user mode, when X is not running at all. It shows *a* difference, but perhaps not the *same* difference. Please humour me and rule it out. Okay. I am in the process of recompiling all my ports, so after that is done I will boot with a GENERIC kernel and see what happens. -- Nate Eldredge [EMAIL PROTECTED] ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: SCHED_4BSD bad interactivity on 7.0 vs 6.3
On Sun, Jul 13, 2008 at 03:11:23AM +0200, Kris Kennaway wrote: > >It seems like there has been a regression in interactivity from > >6.3-RELEASE to 7.0-RELEASE when using the SCHED_4BSD scheduler. After > >upgrading my single-cpu amd64 box, 7.0 has much worse latency. When > >running a kernel compile, there is a noticeable lag to echo my typing or > >scroll my browser windows, and playing an mp3 frequently cuts out for a > >second or two. This did not happen on 6.3-RELEASE. > > Are you sure it's not the x.org server bug that was present in the > version shipped with 7.0? No, it's not. I have exactly the same problem with SCHED_4BSD after upgrade from 6.3-STABLE to 7.0-STABLE. I didn't upgrade my x.org 6.9.0, only OS (all 6.x compat shims are installed). There is some sort of regression, certainly. Eugene Grosbein ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: SCHED_4BSD bad interactivity on 7.0 vs 6.3
Nate Eldredge wrote: On Sun, 13 Jul 2008, Kris Kennaway wrote: Nate Eldredge wrote: Hi folks, Hopefully this is a good list for this topic. It seems like there has been a regression in interactivity from 6.3-RELEASE to 7.0-RELEASE when using the SCHED_4BSD scheduler. After upgrading my single-cpu amd64 box, 7.0 has much worse latency. When running a kernel compile, there is a noticeable lag to echo my typing or scroll my browser windows, and playing an mp3 frequently cuts out for a second or two. This did not happen on 6.3-RELEASE. Are you sure it's not the x.org server bug that was present in the version shipped with 7.0? Update to the latest version and see if your X interactivity improves. Yes, I had not yet upgraded my x.org port when testing this, so it was the same x.org that was fine under 6.3. Also: I wrote a small program which forks two processes that run gettimeofday() in a tight loop to see how long they get scheduled out. On 6.3 the maximum latency is usually under 100 ms. On 7.0 it is 500 ms or more even when nothing else is running on the system. When a compile is also running it is sometimes 1400 ms or more. This test shows a difference even in single user mode, when X is not running at all. It shows *a* difference, but perhaps not the *same* difference. Please humour me and rule it out. Kris ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: SCHED_4BSD bad interactivity on 7.0 vs 6.3
On Sun, Jul 13, 2008 at 01:34:11AM -0700, Nate Eldredge wrote: > On Sun, 13 Jul 2008, Kris Kennaway wrote: > > > Nate Eldredge wrote: > >> I wrote a small program which forks two processes that run gettimeofday() > >> in a tight loop to see how long they get scheduled out. On 6.3 the > >> maximum > >> latency is usually under 100 ms. On 7.0 it is 500 ms or more even when > >> nothing else is running on the system. When a compile is also running it > >> is sometimes 1400 ms or more. > > This test shows a difference even in single user mode, when X is not > running at all. I was seeing similar problems (audio stutter during compiles, jerky mouse) after upgrading to 7.0. The box is an Athlon-XP 2400+ with 1GB of RAM. Since removing SMP support from the kernel and switching to ULE, interactivity has been acceptible again. I did not update the xserver at the time, and I can't recall if it has been updated since. Stefan pgpwzVr88QUYs.pgp Description: PGP signature
Re: SCHED_4BSD bad interactivity on 7.0 vs 6.3
On Sun, 13 Jul 2008, Kris Kennaway wrote: Nate Eldredge wrote: Hi folks, Hopefully this is a good list for this topic. It seems like there has been a regression in interactivity from 6.3-RELEASE to 7.0-RELEASE when using the SCHED_4BSD scheduler. After upgrading my single-cpu amd64 box, 7.0 has much worse latency. When running a kernel compile, there is a noticeable lag to echo my typing or scroll my browser windows, and playing an mp3 frequently cuts out for a second or two. This did not happen on 6.3-RELEASE. Are you sure it's not the x.org server bug that was present in the version shipped with 7.0? Update to the latest version and see if your X interactivity improves. Yes, I had not yet upgraded my x.org port when testing this, so it was the same x.org that was fine under 6.3. Also: I wrote a small program which forks two processes that run gettimeofday() in a tight loop to see how long they get scheduled out. On 6.3 the maximum latency is usually under 100 ms. On 7.0 it is 500 ms or more even when nothing else is running on the system. When a compile is also running it is sometimes 1400 ms or more. This test shows a difference even in single user mode, when X is not running at all. -- Nate Eldredge [EMAIL PROTECTED] ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: SCHED_4BSD bad interactivity on 7.0 vs 6.3
Nate Eldredge wrote: Hi folks, Hopefully this is a good list for this topic. It seems like there has been a regression in interactivity from 6.3-RELEASE to 7.0-RELEASE when using the SCHED_4BSD scheduler. After upgrading my single-cpu amd64 box, 7.0 has much worse latency. When running a kernel compile, there is a noticeable lag to echo my typing or scroll my browser windows, and playing an mp3 frequently cuts out for a second or two. This did not happen on 6.3-RELEASE. Are you sure it's not the x.org server bug that was present in the version shipped with 7.0? Update to the latest version and see if your X interactivity improves. Kris I wrote a small program which forks two processes that run gettimeofday() in a tight loop to see how long they get scheduled out. On 6.3 the maximum latency is usually under 100 ms. On 7.0 it is 500 ms or more even when nothing else is running on the system. When a compile is also running it is sometimes 1400 ms or more. SCHED_ULE is much better, so I've switched over. But it's not the default yet, and most people are still going to be using SCHED_4BSD. It used to be acceptable but now it isn't. Does anyone know why it's regressed so badly? ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
SCHED_4BSD bad interactivity on 7.0 vs 6.3
Hi folks, Hopefully this is a good list for this topic. It seems like there has been a regression in interactivity from 6.3-RELEASE to 7.0-RELEASE when using the SCHED_4BSD scheduler. After upgrading my single-cpu amd64 box, 7.0 has much worse latency. When running a kernel compile, there is a noticeable lag to echo my typing or scroll my browser windows, and playing an mp3 frequently cuts out for a second or two. This did not happen on 6.3-RELEASE. I wrote a small program which forks two processes that run gettimeofday() in a tight loop to see how long they get scheduled out. On 6.3 the maximum latency is usually under 100 ms. On 7.0 it is 500 ms or more even when nothing else is running on the system. When a compile is also running it is sometimes 1400 ms or more. SCHED_ULE is much better, so I've switched over. But it's not the default yet, and most people are still going to be using SCHED_4BSD. It used to be acceptable but now it isn't. Does anyone know why it's regressed so badly? -- Nate Eldredge [EMAIL PROTECTED] ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
