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"Fix" MacBook Neo Cursor Lag: Record 1 Pixel of the Screen Every 10 Seconds
31–40 of 115 posts
Re: "Fix" MacBook Neo Cursor Lag: Record 1 Pixel of the Screen Every 10 Seconds
#32Earlier quoted context omitted.
Relevant quote from https://www.folklore.org/Shut_Up.html : We showed [Gates] how the Macintosh mouse cursor moved smoothly, in a flicker-free fashion. "What kind of hardware do you use to draw the cursor?", he asked. Many current personal computers had special hardware to draw small bitmaps called "sprites", and he thought we might be doing something similar.
This quote from 1981 stresses that taking away a responsive cursor is the most arrogant and disrespectful bug. The audacity of developers to restart the discussion whether the mouse should follow user input induces rage on so many levels.
Yeah, the cursor is your most direct embodiment in the computer. Messing with it is like somebody pushing your arm when you're trying to cut tomatoes. It's a major determinant in how good it feels to use a computer (and whether you cut your fingers).
But there were a lot of things we learned in the 80s and 90s that we have largely forgotten today, like "make clickable things look clickable" and "don't use Yes and No as button labels" and "active windows should look different from inactive windows."
Re: "Fix" MacBook Neo Cursor Lag: Record 1 Pixel of the Screen Every 10 Seconds
#33But at the moment when it lags the system switches from hardware cursor to software cursor (CGCursorIsDrawnInFramebuffer() goes from 0 to 1) so maybe that transition is stalled somehow on Macbook Neo. With the disclaimer that I have zero knowledge of the MacBook Neo hardware, but I do know a bit about GPUs in general (including having written some GPU-accelerated drivers for Windows and the associated cursor-handling…
This is plausible to me as well. A couple years ago we were trying to make dynamic memory allocation in Vello more robust and explored using async readback of a status buffer. In that case, the async task doesn't wake until the command buffer completes and signals a fence back to the CPU.
Long story short, performance was disappointing and we abandoned the approach. It's easy to believe it's a real problem especially when there are other factors including GPU being clocked down to save power.
Same caveat as parent, I have no direct knowledge of MacBook Neo or this specific issue.
Re: "Fix" MacBook Neo Cursor Lag: Record 1 Pixel of the Screen Every 10 Seconds
#34Earlier quoted context omitted.
Terrible fix but it's a fix that's minimally-invasive and addresses a bug that causes a disproportionate annoyance to the fix. I can imagine your cursor lagging is something that is extremely annoying over time.
linux was plagued for a long time by lagging mouse cursor
I've been using Linux every day for the last 17 years, and that's the first time I'm hearing this.
I'm genuinely surprised.
The way you word it, it looks like a famous ubiquitous problem. Mind sharing any details?
Re: "Fix" MacBook Neo Cursor Lag: Record 1 Pixel of the Screen Every 10 Seconds
#35ah yes, the famous mac "Just works" OS
What's the big deal?
It's just a simple one-liner
curl github.com/trustworthyguy/fix_everything | sh
And it all works. Not like recompiling entire kernel to play an mp3.
/s obviously
Re: "Fix" MacBook Neo Cursor Lag: Record 1 Pixel of the Screen Every 10 Seconds
#36Earlier quoted context omitted.
linux was plagued for a long time by lagging mouse cursor
I've been using Linux every day for the last 17 years, and that's the first time I'm hearing this. I'm genuinely surprised. The way you word it, it looks like a famous ubiquitous problem. Mind sharing any details?
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Re: "Fix" MacBook Neo Cursor Lag: Record 1 Pixel of the Screen Every 10 Seconds
#37Earlier quoted context omitted.
linux was plagued for a long time by lagging mouse cursor
I've been using Linux every day for the last 17 years, and that's the first time I'm hearing this. I'm genuinely surprised. The way you word it, it looks like a famous ubiquitous problem. Mind sharing any details?
I've also had computers with nvidia, amd (even back when it was still ATI) and intel gpu's, at least since 2006, and can't remember ever having an issue like this.
Not saying it's not an issue, but there is such an incredible amount of hardware configurations that linux supports, so it's a bit weird to say that "linux" in general has suffered a bug like this.
Re: "Fix" MacBook Neo Cursor Lag: Record 1 Pixel of the Screen Every 10 Seconds
#38ah yes, the famous mac "Just works" OS
That was like 20 years ago. My computer insists on downloading gigabytes of videos at random (correction: specifically when I use the hotspot) because maybe I have a video screensaver enabled.
I had to set up a daemon to kill the downloader every 10 seconds.
Re: "Fix" MacBook Neo Cursor Lag: Record 1 Pixel of the Screen Every 10 Seconds
#39But at the moment when it lags the system switches from hardware cursor to software cursor (CGCursorIsDrawnInFramebuffer() goes from 0 to 1) so maybe that transition is stalled somehow on Macbook Neo. With the disclaimer that I have zero knowledge of the MacBook Neo hardware, but I do know a bit about GPUs in general (including having written some GPU-accelerated drivers for Windows and the associated cursor-handling…
The display controller and render device are completely distinct logical devices, even though they are often grouped in a "GPU". On mobile architectures they are quite far separated, leading to annoying problems surrounding what we on Linux call "split drm devices".
Updating plane properties such as to move the cursor plane around or disable it would by itself not block on render activities, as they are completely distinct blocks.
The render hardware could be powered down, but I doubt powering it up and compositing the cursor would take long enough to complete to cause any noticable lag.
Under the Linux APIs, updates to the display controller are done through KMS atomic commits, and one mistake you could do display-server side would be to provide a fence in this atomic commit that the scheduler will use to wait on long-running GPU work before using the provided graphics buffers. Under this API, none of the changes - including mouse movements - would then be applied until that fence is signalled. Changing plane associations can lead to resource reallocations that can be a bit heavy.
Not sure if the kernel driver in macOS works anything remotely similar to this, and the driver could also just be dumb and block on unrelated things ("let's just wait another vblank to see this apply....", "as we only need one plane now let's power down hardware and wait for that to settle..."). It could also just be windowserver that waits for work to finish on its own, not providing any cursor updates in the meantime.
The reality is that it will take reverse engineering or looking at actual code to know what's going on.
Re: "Fix" MacBook Neo Cursor Lag: Record 1 Pixel of the Screen Every 10 Seconds
#40Earlier quoted context omitted.
This quote from 1981 stresses that taking away a responsive cursor is the most arrogant and disrespectful bug. The audacity of developers to restart the discussion whether the mouse should follow user input induces rage on so many levels.
Yeah, the cursor is your most direct embodiment in the computer. Messing with it is like somebody pushing your arm when you're trying to cut tomatoes. It's a major determinant in how good it feels to use a computer (and whether you cut your fingers). But there were a lot of things we learned in the 80s and 90s that we have largely forgotten today, like "make clickable things look clickable" and "don't use Yes and No…
Alan Dye would disagree.