From: "heming.zhao@suse.com" <heming.zhao@suse.com>
To: David Teigland <teigland@redhat.com>
Cc: "rogerheflin@gmail.com" <rogerheflin@gmail.com>,
"zkabelac@redhat.com" <zkabelac@redhat.com>,
Martin Wilck <martin.wilck@suse.com>,
prajnoha@redhat.com,
"linux-lvm@redhat.com" <linux-lvm@redhat.com>
Subject: Re: [linux-lvm] Discussion: performance issue on event activation mode
Date: Thu, 17 Jun 2021 11:46:55 +0800 [thread overview]
Message-ID: <c5c40605-9859-4086-9717-7381b0309a2c@suse.com> (raw)
In-Reply-To: <20210616163816.GA5811@redhat.com>
On 6/17/21 12:38 AM, David Teigland wrote:
> On Thu, Jun 17, 2021 at 12:18:47AM +0800, heming.zhao@suse.com wrote:
>> I don't know if I missed something, the result didn't show any progress.
>> the result of "devices/obtain_device_list_from_udev=0" even got regression: from 23.3 => 39.8
>>
>> the lvm2 version with dev-dct-device-info-1 branch code
>> ```
>> sle15sp2-base40g:~ # lvm version
>> LVM version: 2.03.13(2)-git (2021-05-07)
>> Library version: 1.02.179-git (2021-05-07)
>> Driver version: 4.40.0
>> Configuration: ./configure --host=x86_64-suse-linux-gnu --build=x86_64-suse-linux-gnu --program-prefix= --disable-dependency-tracking --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/lib --localstatedir=/var --sharedstatedir=/var/lib --mandir=/usr/share/man --infodir=/usr/share/info --disable-dependency-tracking --enable-dmeventd --enable-cmdlib --enable-udev_rules --enable-udev_sync --with-udev-prefix=/usr/ --enable-selinux --enable-pkgconfig --with-usrlibdir=/usr/lib64 --with-usrsbindir=/usr/sbin --with-default-dm-run-dir=/run --with-tmpfilesdir=/usr/lib/tmpfiles.d --with-thin=internal --with-device-gid=6 --with-device-mode=0640 --with-device-uid=0 --with-dmeventd-path=/usr/sbin/dmeventd --with-thin-check=/usr/sbin/thin_check --with-thin-dump=/usr/sbin/thin_dump --with-thin-repair=/usr/sbin/thin_repair --enable-blkid_wiping --enable-lvmpolld --enable-
realtime --with-cache=internal --with-default-locking-dir=/run/lock/lvm --with-default-pid-dir=/run --with-default-run-dir=/run/lvm --enable-fsadm --disable-silent-rules --enable-write_install --with-vdo=none
>> ```
>>
>> Installation with cmd: make install && dracut -f --add "lvm"
>>
>> top 10 blame services
>> ```
>> external_device_info_source = "none"
>> obtain_device_list_from_udev = 1
>> event_activation = 1
>> udev_sync = 1
>
> Thanks for running that again. From your previous testing, my conclusion
> was that libudev caused the slowdown. So, the patch is supposed to avoid
> all libudev calls by default, and rely only on lvm's native device type
> detection. The default settings to avoid libudev, are:
>
> obtain_device_list_from_udev = 0
> external_device_info_source = "none"
>
> I'm not sure which of your test results match those settings, but if those
> results are not improved, then we should look further to see if the
> slowdown is caused by something other than libudev calls.
>
the default value of external_device_info_source is "none" and I didn't change it.
So below (from my last mail) is your wanted result, it's worse than before (23.3 vs 39.8).
```
devices/obtain_device_list_from_udev=0
global/event_activation=1
activation/udev_sync=1
sle15sp2-base40g:~ # systemd-analyze blame | head -n 10
39.845s lvm2-pvscan@133:576.service
39.830s lvm2-pvscan@133:640.service
39.829s lvm2-pvscan@133:720.service
39.827s lvm2-pvscan@132:736.service
39.825s lvm2-pvscan@132:656.service
39.823s lvm2-pvscan@132:672.service
39.821s lvm2-pvscan@132:720.service
39.820s lvm2-pvscan@132:544.service
39.819s lvm2-pvscan@132:624.service
39.808s lvm2-pvscan@132:576.servic
```
the booting time out problem cause by two side:
1> libudev take much time
2> thousands of lvm2-pvscan@.service running on the same time
the new patch or existing code (with obtain_device_list_from_udev=0) can avoid <1>.
but <2> is still not to avoid. (direct activation can avoid it)
Thanks,
heming
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next prev parent reply other threads:[~2021-06-17 3:47 UTC|newest]
Thread overview: 86+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-06 6:15 [linux-lvm] Discussion: performance issue on event activation mode heming.zhao
2021-06-06 16:35 ` Roger Heflin
2021-06-07 10:27 ` Martin Wilck
2021-06-07 15:30 ` heming.zhao
2021-06-07 15:45 ` Martin Wilck
2021-06-07 20:52 ` Roger Heflin
2021-06-07 21:30 ` David Teigland
2021-06-08 8:26 ` Martin Wilck
2021-06-08 15:39 ` David Teigland
2021-06-08 15:47 ` Martin Wilck
2021-06-08 16:02 ` Zdenek Kabelac
2021-06-08 16:05 ` Martin Wilck
2021-06-08 16:03 ` David Teigland
2021-06-08 16:07 ` Martin Wilck
2021-06-15 17:03 ` David Teigland
2021-06-15 18:21 ` Zdenek Kabelac
2021-06-16 16:18 ` heming.zhao
2021-06-16 16:38 ` David Teigland
2021-06-17 3:46 ` heming.zhao [this message]
2021-06-17 15:27 ` David Teigland
2021-06-08 16:49 ` heming.zhao
2021-06-08 16:18 ` heming.zhao
2021-06-09 4:01 ` heming.zhao
2021-06-09 5:37 ` Heming Zhao
2021-06-09 18:59 ` David Teigland
2021-06-10 17:23 ` heming.zhao
2021-06-07 15:48 ` Martin Wilck
2021-06-07 16:31 ` Zdenek Kabelac
2021-06-07 21:48 ` David Teigland
2021-06-08 12:29 ` Peter Rajnoha
2021-06-08 13:23 ` Martin Wilck
2021-06-08 13:41 ` Peter Rajnoha
2021-06-08 13:46 ` Zdenek Kabelac
2021-06-08 13:56 ` Peter Rajnoha
2021-06-08 14:23 ` Zdenek Kabelac
2021-06-08 14:48 ` Martin Wilck
2021-06-08 15:19 ` Peter Rajnoha
2021-06-08 15:39 ` Martin Wilck
2021-09-09 19:44 ` David Teigland
2021-09-10 17:38 ` Martin Wilck
2021-09-12 16:51 ` heming.zhao
2021-09-27 10:00 ` Peter Rajnoha
2021-09-27 15:38 ` David Teigland
2021-09-28 6:34 ` Martin Wilck
2021-09-28 14:42 ` David Teigland
2021-09-28 15:16 ` Martin Wilck
2021-09-28 15:31 ` Martin Wilck
2021-09-28 15:56 ` David Teigland
2021-09-28 18:03 ` Benjamin Marzinski
2021-09-28 17:42 ` Benjamin Marzinski
2021-09-28 19:15 ` Martin Wilck
2021-09-29 22:06 ` Peter Rajnoha
2021-09-30 7:51 ` Martin Wilck
2021-09-30 8:07 ` heming.zhao
2021-09-30 9:31 ` Martin Wilck
2021-09-30 11:41 ` Peter Rajnoha
2021-09-30 15:32 ` heming.zhao
2021-10-01 7:41 ` Martin Wilck
2021-10-01 8:08 ` Peter Rajnoha
2021-09-30 11:29 ` Peter Rajnoha
2021-09-30 16:04 ` David Teigland
2021-09-30 14:41 ` Benjamin Marzinski
2021-10-01 7:42 ` Martin Wilck
2021-09-29 21:53 ` Peter Rajnoha
2021-09-30 7:45 ` Martin Wilck
2021-09-29 21:39 ` Peter Rajnoha
2021-09-30 7:22 ` Martin Wilck
2021-09-30 14:26 ` David Teigland
2021-09-30 15:55 ` David Teigland
2021-10-01 8:00 ` Peter Rajnoha
2021-10-18 6:24 ` Martin Wilck
2021-10-18 15:04 ` David Teigland
2021-10-18 16:56 ` heming.zhao
2021-10-18 21:51 ` Zdenek Kabelac
2021-10-19 17:18 ` David Teigland
2021-10-20 14:40 ` Martin Wilck
2021-10-20 14:50 ` David Teigland
2021-10-20 14:54 ` Martin Wilck
2021-10-20 15:12 ` David Teigland
2021-06-07 16:40 ` David Teigland
2021-07-02 21:09 ` David Teigland
2021-07-02 21:22 ` Martin Wilck
2021-07-02 22:02 ` David Teigland
2021-07-03 11:49 ` heming.zhao
2021-07-08 10:10 ` Tom Yan
2021-07-02 21:31 ` Tom Yan
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