Performamce Issue - 'update' loop when sliderPerView is auto and slides have fixed widths

[mattwills8]

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Reproduction link

https://github.com/mattwills8/swiper-perf-issues-repro/tree/main

Bug description

When slides per view is set to 'auto', and my slides have a fixed width, I'm seeing the swiper 'update' function run multiple times on the window 'load' event. In my production app this is creating a long blocking task, sometimes up to multiple seconds, and is causing significant performance issues.

Here's a screenshot from a profile of my app.

Zooming in we see a huge number of swiper 'update' calls.

In the minimal repro repo I've attached here, you can see a similar 'update' and 'load' loop (although for some reason split into separate tasks... that could be a framework related difference?).

It seems like having a carousel with fixed width slides like my example should be one of the most basic uses of a carousel for a responsive site, so it's entirely possible that I'm doing something wrong in my usage of it.

Any help would be hugely appreciated.

Expected Behavior

No response

Actual Behavior

No response

Swiper version

11.1.1

Platform/Target and Browser Versions

macOS Chrome

Validations

• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.
• Make sure this is a Swiper issue and not a framework-specific issue

Would you like to open a PR for this bug?

• I'm willing to open a PR