UI freezes on fdatasync #7952

rnz · 2020-05-26T20:52:40Z

Steps to reproduce

About ui freezes

run strace with ignore some operations

sudo strace -e 'trace=!recvmsg,poll,writev,stat,futex' -p $(pgrep Telegram) 2>&1 | egrep -v 'read\(5|write\(5'

type some text in message input box
catch some freezes on fdatasync:

getpid()                                = 69543
getpid()                                = 69543
access("/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C96s", F_OK) = 0
access("/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C96s", W_OK) = 0
lstat("/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C96s", {st_mode=S_IFREG|0664, st_size=364, ...}) = 0
openat(AT_FDCWD, "/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C", O_RDWR|O_CLOEXEC|O_TMPFILE, 0600) = 41
access("/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C96s", R_OK) = 0
access("/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C96s", W_OK) = 0
access("/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C96s", X_OK) = -1 EACCES (Permission denied)
fchmod(41, 0664)                        = 0
fstat(41, {st_mode=S_IFREG|0664, st_size=0, ...}) = 0
write(41, "TDF$o\210\36\0\0\0\0\360_\230r\7\27@K\v\356\0t\221\240\262\36\334\203-\227\326"..., 268) = 268
lseek(41, 0, SEEK_SET)                  = 0
fdatasync(41)                           = 0
linkat(AT_FDCWD, "/proc/self/fd/41", AT_FDCWD, "/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C96s", AT_SYMLINK_FOLLOW) = -1 EEXIST (File exists)
linkat(AT_FDCWD, "/proc/self/fd/41", AT_FDCWD, "/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C96s.cvzUPK", AT_SYMLINK_FOLLOW) = 0
close(41)                               = 0
rename("/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C96s.cvzUPK", "/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C96s") = 0
unlink("/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C960") = -1 ENOENT (No such file or directory)
unlink("/home/rnz/.TelegramDesktop/tdata/D877F783D5D3EF8C/E66391AC0BDD1C961") = -1 ENOENT (No such file or directory)

Expected behaviour

No UI freezes on background io operations

Actual behaviour

Freezes.

Configuration

Operating system:
$ lsb_release -a
LSB Version: core-11.1.0ubuntu2-noarch:printing-11.1.0ubuntu2-noarch:security-11.1.0ubuntu2-noarch
Distributor ID: Ubuntu
Description: Ubuntu 20.04 LTS
Release: 20.04
Codename: focal

Version of Telegram Desktop:
2.1.7

Installation source (Linux Only) - the official website / GitHub releases / flatpak / snap / distribution package:
GitHub releases

Used theme:
Night

Additional info:
My /home placed on zfs pool (two hdd in mirror with zlog on nvme ssd) and zfs before version 0.8 didn't support O_DIRECT and operation fdatasync didn't wait disk io. But now zfs support O_DIRECT and operations such as fdatasync now have write time penalties. And for example now when zfs run scrub Telegram is almost completly unusable by freezes because too often call sync operations and not exec this operations in background and have impact on the user interface.

I think fdatasync doesn't need for Telegram - linux fs drivers, vfs and also zfs write stack already have own tunable strategy for sync. But if Telegram is need fsyncdata - that operation must be run in background without impact UI

Also Telegram have too many operations stat("/etc/localtime", ...) on mouse hover action on groups:

...
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=1535, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=1535, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=1535, ...}) = 0
...

I think this is overhead too

The text was updated successfully, but these errors were encountered:

ilya-fedin · 2020-05-26T21:28:56Z

Also Telegram have too many operations stat("/etc/localtime", ...) on mouse hover action on groups:

Looks like Qt parses this file on each time request and this can't be solved in tdesktop:
https://github.com/qt/qtbase/blob/dev/src/corelib/time/qtimezoneprivate_tz.cpp#L1124

ilya-fedin · 2020-05-26T22:08:39Z

type some text in message input box

catch some freezes on fdatasync:

Probably it's due to recent switching to QSaveFile to avoid logout on power outage, and it is called when saving drafts 🤔
2ad48f1

rnz · 2020-05-27T08:09:10Z

Also Telegram have too many operations stat("/etc/localtime", ...) on mouse hover action on groups:

Looks like Qt parses this file on each time request and this can't be solved in tdesktop:
https://github.com/qt/qtbase/blob/dev/src/corelib/time/qtimezoneprivate_tz.cpp#L1124

Why tdesktop need a time request when hovering over the mouse cursor?

ilya-fedin · 2020-05-27T08:15:10Z

Why tdesktop need a time request when hovering over the mouse cursor?

🤔 probably, for tooltip or to update the time on the item

rnz · 2020-05-27T13:24:56Z

@ilya-fedin I don't saw any actions by hovering (no hints, no time updates) in tdesktop

And I think this is wrong(or old style) call: if (open(save, 's')) {
May be need use save.open() with https://doc.qt.io/qt-5/qiodevice.html#OpenModeFlag-enum ?

ilya-fedin · 2020-05-27T13:28:53Z

And I think this is wrong(or old style) call: if (open(save, 's')) {

No, it's FileWriteDescriptor::open

ilya-fedin · 2020-05-27T13:36:31Z

I don't saw any actions by hovering (no hints, no time updates) in tdesktop

You can't see any difference since it's the same post probably

cypa · 2020-06-12T04:50:28Z

my disk io is slow and freezes are crazy long while I type new message ...
"QSaveFile ... and it is called when saving drafts" - is it synchronous disk io on typing new message? crazy! из пушки по воробьям! how do I disable drafts at all?

rnz · 2020-06-13T22:28:03Z

This is so stupid bug - when running some io operations on filesystem (such as scrubbing on zfs) - Telegram is complete unusable.

cypa · 2020-06-14T04:16:17Z

friend, put dir like this
.local/share/TelegramDesktop/tdata/D877F783D5D3EF8C
to tmpfs into RAM
that's a makeshift but it works, no lags

rnz · 2020-06-30T22:28:54Z

friend, put dir like this
.local/share/TelegramDesktop/tdata/D877F783D5D3EF8C
to tmpfs into RAM
that's a makeshift but it works, no lags

Thanks but this workaround is ugly.

I think behaviour - when changes in input box is put to disk - must be configurable (off, custom period) and of course next need to be fix ui bug with freezes.

GaurangTandon · 2020-07-15T12:48:24Z

@cypa Thanks, I tried this trick, it did entirely get rid of the freezing. Awesome! However, now my telegram desktop resets every time I restart my pc. Which means I have to login again, enter otp, and enter 2fa password every time, and it resets all my settings too :( This is expected since I loaded Telegram Desktop into RAM, but still :(

jonathonf · 2020-07-16T20:39:51Z

Another workaround is to use eatmydata/libeatmydata, e.g. eatmydata telegram-desktop or LD_PRELOAD=/usr/lib/libeatmydata.so telegram-desktop

It "is designed to transparently disable fsync and friends" - the lack of write safety won't be a concern if you're already putting this data in volatile storage.

I've updated my desktop shortcuts already... 😁

rnz · 2020-08-23T15:11:12Z

Another workaround is to use eatmydata/libeatmydata, e.g. eatmydata telegram-desktop or LD_PRELOAD=/usr/lib/libeatmydata.so telegram-desktop

It "is designed to transparently disable fsync and friends" - the lack of write safety won't be a concern if you're already putting this data in volatile storage.

I've updated my desktop shortcuts already...

This workaroud unfortunately not working...

jonathonf · 2020-09-03T13:40:14Z

Not working in what way, @rnz ?

You can't get the preload to work, or it doesn't fix the issue completely?

rnz · 2020-10-02T21:47:07Z

Not working in what way, @rnz ?
You can't get the preload to work, or it doesn't fix the issue completely?

It doesn't fix the issue - freezes on input still present when telegram save text from input field

Dimensional · 2020-10-28T16:55:01Z

This is rather annoying. Telegram sometimes flat out crashes when it hangs due to this, though that hasn't happened for a few weeks. I disabled Spellcheck and it still hangs when saving the draft. Is it trying to write to an actual file or save the draft to a cache in memory? Since I'm running on HDD, the freezing would be very prominent with the seek time.

rnz · 2020-11-06T11:44:40Z

@ilya-fedin hi man! Is there any progress with fix this bug?

ilya-fedin · 2020-11-06T15:57:51Z

I don't know, ask @john-preston

rnz · 2020-11-06T22:22:56Z

@john-preston same question?

john-preston · 2020-11-07T09:29:18Z

@rnz I have a patch that moves all fdatasync-s to the background thread, I think I'll add it to the next beta release.

grandsilence · 2021-02-23T10:50:17Z

@john-preston Still no solution even in the latest beta? The slowness during typing is very annoying.

cyb3rd4d · 2021-02-23T11:06:50Z

If that can help, I recently discovered that the TRIM was not enabled on my system because I encrypted my SSD through dm-crypt and in that case TRIM is not automatically enabled for security purposes: https://wiki.archlinux.org/index.php/Dm-crypt/Specialties#Discard/TRIM_support_for_solid_state_drives_(SSD)
I enabled the TRIM and got excellent performances since then.

grandsilence · 2021-02-23T11:10:31Z

@MartialGeek I already have TRIM activated for all drives. But it doesn't help. I will try to transfer Telegram Data to RAM drive.

ilya-fedin · 2021-02-23T11:17:46Z

I will try to transfer Telegram Data to RAM drive.

You had a different issue with spellchecker rather than with fdatasync IIRC, hadn't you?

grandsilence · 2021-02-23T11:22:04Z

@ilya-fedin Yes, there was a problem with the spellchecker when the processor got overloaded when typing long words or ".........." (many special characters). This problem has been fixed, thanks for that. But the problem with microlags while typing doesn't disappear even if you turn off spellchecker.

OS: Windows 10 x64 1803
Telegram Version: 2.5.9 (beta)

ilya-fedin · 2021-02-23T11:23:06Z

This problem has been fixed, thanks for that.

Why don't you close your issue then?

grandsilence · 2021-02-23T11:25:02Z

@ilya-fedin I'm going to close now, referring to this thread.

john-preston · 2021-02-23T12:29:10Z

@grandsilence Today (I hope) will be a next stable release, then maybe some bug-fix releases and then I hope to deploy a new beta version where I'll try to enable moving all fdatasync-s to a background thread.

grandsilence · 2021-02-23T13:25:00Z

@john-preston Thank you very much. I'll be waiting.

rnz · 2021-05-01T14:16:13Z

How long to wait?

grandsilence · 2021-05-01T16:22:38Z

@john-preston any news about the issue?

Younes-L · 2021-05-05T01:12:38Z

@grandsilence @rnz new beta 2.7.5 with fdatasync in background thread, check it out

If it doesn't fix the freezing for you there's still cypa's trick which works flawlessly

grandsilence · 2021-05-09T23:47:32Z

@Younes-L Switched to new beta 2.7.5. Looks like the problem has been solved!
Finally, all the micro-lags disappeared during typing.
Thank you so much ❤

github-actions · 2021-06-24T05:00:30Z

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.

ilya-fedin mentioned this issue Jun 26, 2020

app freeze while writing #8142

Closed

This was referenced Jun 26, 2020

Lagging keyboard input on Linux #7530

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Client brakes #7579

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Aokromes mentioned this issue Jul 14, 2020

App freezes frequently #8253

Closed

ilya-fedin mentioned this issue Aug 11, 2020

Telegram freezes when typing into the window #8416

Closed

ilya-fedin mentioned this issue Aug 20, 2020

Window constantly freezes #8462

Closed

ilya-fedin mentioned this issue Sep 18, 2020

[BUG] Typing lots of periods (.) in chats causes CPU usage to skyrocket. #8612

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Aokromes added the bug label Oct 5, 2020

ilya-fedin mentioned this issue Oct 15, 2020

100% CPU usage and slow input response when Windows spellchecking is enabled #8833

Closed

Aokromes closed this as completed May 10, 2021

github-actions bot locked as resolved and limited conversation to collaborators Jun 24, 2021

UI freezes on fdatasync #7952

UI freezes on fdatasync #7952

Comments

rnz commented May 26, 2020 • edited Loading

Steps to reproduce

Expected behaviour

Actual behaviour

Configuration

ilya-fedin commented May 26, 2020

ilya-fedin commented May 26, 2020

rnz commented May 27, 2020

ilya-fedin commented May 27, 2020

rnz commented May 27, 2020

ilya-fedin commented May 27, 2020

ilya-fedin commented May 27, 2020 • edited Loading

cypa commented Jun 12, 2020

rnz commented Jun 13, 2020 • edited Loading

cypa commented Jun 14, 2020

rnz commented Jun 30, 2020

GaurangTandon commented Jul 15, 2020

jonathonf commented Jul 16, 2020

rnz commented Aug 23, 2020

jonathonf commented Sep 3, 2020

rnz commented Oct 2, 2020 • edited Loading

Dimensional commented Oct 28, 2020 • edited Loading

rnz commented Nov 6, 2020 • edited Loading

ilya-fedin commented Nov 6, 2020

rnz commented Nov 6, 2020

john-preston commented Nov 7, 2020

grandsilence commented Feb 23, 2021

cyb3rd4d commented Feb 23, 2021

grandsilence commented Feb 23, 2021

ilya-fedin commented Feb 23, 2021

grandsilence commented Feb 23, 2021 • edited Loading

ilya-fedin commented Feb 23, 2021

grandsilence commented Feb 23, 2021

john-preston commented Feb 23, 2021

grandsilence commented Feb 23, 2021

rnz commented May 1, 2021

grandsilence commented May 1, 2021

Younes-L commented May 5, 2021

grandsilence commented May 9, 2021

github-actions bot commented Jun 24, 2021

rnz commented May 26, 2020 •

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ilya-fedin commented May 27, 2020 •

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rnz commented Jun 13, 2020 •

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rnz commented Oct 2, 2020 •

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Dimensional commented Oct 28, 2020 •

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rnz commented Nov 6, 2020 •

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grandsilence commented Feb 23, 2021 •

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