| Summary: | [IVB/BDW Bisected] Firefox-fishbowl.trace and Firefox-fishtank.trace performance reduced ~96% | ||
|---|---|---|---|
| Product: | cairo | Reporter: | wendy.wang |
| Component: | xlib backend | Assignee: | Chris Wilson <chris> |
| Status: | RESOLVED MOVED | QA Contact: | cairo-bugs mailing list <cairo-bugs> |
| Severity: | major | ||
| Priority: | high | ||
| Version: | unspecified | ||
| Hardware: | Other | ||
| OS: | All | ||
| Whiteboard: | |||
| i915 platform: | i915 features: | ||
| Attachments: |
dmesg file
Xorg log |
||
|
Description
wendy.wang
2014-12-18 11:53:02 UTC
Created attachment 110982 [details]
Xorg log
If the filter is left at the default of CAIRO_FILTER_GOOD this is to be expected. Changing the filter to CAIRO_FILTER_BILINEAR should restore the speed. An actual fix will require adding code to pixman so that the filtering can be done in the X server. Otherwise making images into pixmaps in an attempt to speed things up actually make it slower as they just have to be read back into the client program to do the transform. It may also be necessary to implement 2-pass filtering. Has a bug been filed about this with Pixman? If so, can we close this bug as wontfix, since the performance delta is a documented change for 1.14? I also wonder if the test suite needs to be modified to use the faster scaling? Submitted bug 89499 - [IVB/BDW Bisected] Pixmap need filter CAIRO_FILTER_GOOD and CAIRO_FILTER_BILINEAR to track the actual fix solution. And close this bug as will not fix. This bug is in the xlib backend not pixman. (Remember that even at best, pixman will be orders of magnitude slower than a GPU here.) I would like to see some indication that code submitted to pixman will be merged or at least looked at. Currently a patch to move the filtering from Cairo to Pixman has been outstanding on the mailing list for 4 months with no feedback. If this was merged I would like to try working on a true 2-pass algorithm which can only be done in Pixman, not in Cairo. I got feedback for an earlier version of the patch. I believe I addressed the problems listed in the feedback, but even if not new feedback would be appreciated. Patch is in Pixman mailing list, message id <1419385932-13261-1-git-send-email-spitzak@gmail.com> -- GitLab Migration Automatic Message -- This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity. You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/cairo/cairo/issues/117. |
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.