RESOLVED DUPLICATE of bug 168657 150445
Flexbox - flex direction column slow layout performance 
https://bugs.webkit.org/show_bug.cgi?id=150445
Summary Flexbox - flex direction column slow layout performance
Scott Bobertson
Reported Thursday, October 22, 2015 3:37:26 PM UTC
Nested divs with 'display: flex' and 'flex-direction: column' have very slow performance in Safari. At a depth of 18 divs with these CSS properties Safari takes a total of 6578ms to layout and paint the divs this time grows exponentially as the depth of divs increases. This same test performed on Chrome or Firefox takes 2ms. Here is a demo of the problem. (open the console to see the results) http://codepen.io/anon/pen/zvRKYN?editors=001
Attachments
Add attachment proposed patch, testcase, etc.
Radar WebKit Bug Importer
Comment 1 Thursday, October 22, 2015 7:51:14 PM UTC
<rdar://problem/23222219>
James Seigel
Comment 2 Tuesday, December 13, 2016 8:01:58 PM UTC
Still seems to be a critical problem. Definitely causes issues when nesting, or when products create deep nesting like react-native-web for example.
l1657572
Comment 3 Tuesday, February 7, 2017 8:20:11 AM UTC
I can confirm. I'm currently using a Flexbox framework which renders great on Chrome and Firefox, but slows to a crawl on Safari. Major issue.
Jon Lee
Comment 4 Tuesday, February 28, 2017 6:51:23 PM UTC
This is fixed with the latest flex box checkin in b168657. *** This bug has been marked as a duplicate of bug 168657 ***
Note You need to log in before you can comment on or make changes to this bug.