From 0d9a54aa975e050ba044271a48c037416b5d54ca Mon Sep 17 00:00:00 2001 From: =?utf8?q?Michel=20D=C3=A4nzer?= Date: Fri, 26 Apr 2024 12:44:52 +0200 Subject: [PATCH] xwayland/present: Skip queued flip when a new one becomes ready If multiple flips become ready for the same MSC, we would previously execute them all sequentially, one per MSC for sync flips. This could result in an unbounded flip queue and corresponding memory consumption. With implicit sync, leave the mailbox handling to the compositor for async flips though. v2: * Use present_vblank_rec::sync_flip. Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1664 Fixes: e1f16fb1aca5 ("xwayland: don't scrap pending present requests") Part-of: --- hw/xwayland/xwayland-present.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/hw/xwayland/xwayland-present.c b/hw/xwayland/xwayland-present.c index 43f053dfb..60427cca0 100644 --- a/hw/xwayland/xwayland-present.c +++ b/hw/xwayland/xwayland-present.c @@ -1053,6 +1053,25 @@ retry: } if (flip_pending && vblank->flip && !notify_only) { + present_vblank_ptr flip_queued_last; + + flip_queued_last = xorg_list_last_entry(&xwl_present_window->flip_queue, + present_vblank_rec, event_queue); + + /* Do mailbox handling for queued flips, to prevent the flip queue from + * growing unbounded. + */ + if (flip_queued_last != flip_pending && + (flip_queued_last->sync_flip +#ifdef DRI3 + || vblank->acquire_syncobj +#endif + )) { + xorg_list_del(&flip_queued_last->event_queue); + present_vblank_scrap(flip_queued_last); + xwl_present_re_execute(flip_queued_last); + } + DebugPresent(("\tr %" PRIu64 " %p (pending %p)\n", vblank->event_id, vblank, flip_pending)); xorg_list_append(&vblank->event_queue, &xwl_present_window->flip_queue); -- 2.11.4.GIT