notmuch-show-mode: slowdown due to redisplay

notmuch-show-mode: slowdown due to redisplay

[Rainer Gemulla]

Navigating certain messages (e.g., with many attachments or images) may become very slow in notmuch-show-mode. I see this rarely, but when it happens, it takes >1s to simply move the point so that the buffer is barely usable. The CPU profiler shows that notmuch-show-command-hook calls redisplay and that's that all where the time goes. Not sure if anything can be done about this.

Re: notmuch-show-mode: slowdown due to redisplay

[David Bremner]

Rainer Gemulla <hqn1@gmx.de> writes:

> Navigating certain messages (e.g., with many attachments or images)
> may become very slow in notmuch-show-mode. I see this rarely, but when
> it happens, it takes >1s to simply move the point so that the buffer
> is barely usable. The CPU profiler shows that
> notmuch-show-command-hook calls redisplay and that's that all where
> the time goes. Not sure if anything can be done about this.

Hmm. Hard to debug without a sample message, or a more definite
pattern. Do you notice a threshold in terms of numbers of attachements?
I can imagine there is some bad behaviour involving large numbers of
buttons when running redisplay.

d

Re: notmuch-show-mode: slowdown due to redisplay

[Rainer Gemulla]

>> Navigating certain messages (e.g., with many attachments or images)
>> may become very slow in notmuch-show-mode. I see this rarely, but when
>> it happens, it takes >1s to simply move the point so that the buffer
>> is barely usable. The CPU profiler shows that
>> notmuch-show-command-hook calls redisplay and that's that all where
>> the time goes. Not sure if anything can be done about this.
>
> Hmm. Hard to debug without a sample message, or a more definite
> pattern. Do you notice a threshold in terms of numbers of attachements?
> I can imagine there is some bad behaviour involving large numbers of
> buttons when running redisplay.

I've tracked it down: it happens when multiple large images are attached to the email (and displayed inline) and global-hl-line-mode is turned on. The former slows down redisplay, the latter makes redisplay do something with every cursor movement.

Re: notmuch-show-mode: slowdown due to redisplay

[David Bremner]

Rainer Gemulla <hqn1@gmx.de> writes:

>
> I've tracked it down: it happens when multiple large images are
> attached to the email (and displayed inline) and global-hl-line-mode
> is turned on. The former slows down redisplay, the latter makes
> redisplay do something with every cursor movement.

I made a test message with 10 copies of a (black and white) 3k x 3k
jpeg image, enabled global-hl-line-mode, but I don't notice any
navigation problems. I wonder if there could be an interaction with some
other package? Or do I need bigger / more images?

d

Re: notmuch-show-mode: slowdown due to redisplay

[Rainer Gemulla]

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>> I've tracked it down: it happens when multiple large images are
>> attached to the email (and displayed inline) and global-hl-line-mode
>> is turned on. The former slows down redisplay, the latter makes
>> redisplay do something with every cursor movement.
>
> I made a test message with 10 copies of a (black and white) 3k x 3k
> jpeg image, enabled global-hl-line-mode, but I don't notice any
> navigation problems. I wonder if there could be an interaction with some
> other package? Or do I need bigger / more images?

It's not consistent, apparently. I do have a message (with 2 images and multiple PDF attachments) where it looks like this:

       15095  97% - notmuch-show-command-hook
       15095  97%  - redisplay
          16   0%   - redisplay_internal (C function)
          16   0%    - eval
          16   0%       spaceline-ml-main

when global-hl-line-mode is on. Unfortunately, I cannot share this message. Generally, it only happens when one of the attached images is visible in the window.

If I stumble across this problem with a message that I can share, I'll post it here.

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