guess i'm marked safe!
They almost never do live that long, for whatever reason, but they should.
Current `uptime` on my work MacBook (macOS 15.7.4):
17:14 up 50 days, 22 mins, 16 users, load averages: 2.06 1.95 1.94
My personal iMac is at 279 days of uptime.
If the count it returns keeps growing, you're seeing a slow leak. At some point, new connections will start failing. How soon depends entirely on how quickly your machine closes new connections.
Since a lot of client traffic involves the server closing connections instead, I imagine it could take a while.
It's unclear if it'll leak whenever your mac closes or only when it fails to get a (FIN, ACK) back from the peer so the TCP_WAIT garbage collector runs. If it's the latter, then it could take substantially longer, depending on connection quality.
% netstat -an | grep -c TIME_WAIT | wc -l
1Mac `grep -c` counts lines that match, so it always prints 1 line, so piping to wc -l will always return 1.
Or just open up and do netstat -an |grep TCP_WAIT and just watch it. If any don't disappear after a few minutes, then you're seeing the issue.
I also can't reproduce. I want to say I have encountered this issue at least once, yesterday I before rebooted my uptime was 60 days.
But it's not instant, it just never releases connections. So you can have uptime of 3 years and not run out of connections or run out shortly after hitting that issue.
calc_tcp_overflow_time.fish: https://gist.github.com/daveorzach/64538f82a89fa24e5d134557c...
monitor_tcp_time_wait.fish: https://gist.github.com/daveorzach/0964a7a67c08c50043ff707cf...
The longest uptime I have had on any of my recent laptops is probably around 90 days but that’s because that laptop was sitting in my garage with wall power connected (probably bad for the battery) and some external storage connected and I’d remote into that machine over WireGuard now and then. When I did reboot that machine it was only out of habit that I accidentally clicked on reboot via a remote graphical session.
Most of the time my remote use of the laptop in the garage would be ssh sessions, but occasionally I’d use Remote Desktop. Right after I clicked reboot in the Remote Desktop session I realized what mistake I had just done - I have WireGuard set up to start after login. So after the reboot, I was temporarily unable to get back in. As I was in another country I couldn’t just walk over to the garage. But I do have family that could, so I instructed one of them over the phone on how to log in for me so that WireGuard would automatically start back up. You’d think this would happen only once, but I probably had to send family to the garage on my behalf maybe three or four times after me having made the same mistake again.
For the laptops that I actually carry around and plug and unplug things to etc, normal amount of time between reboots for me is somewhere between every 1 and 3 days. Cold boot is plenty fast anyway, so shutting it down after a day of work or when ejecting an external HDD or SSD doesn’t really cost me any noticeable amount of time.
That sounds... a bit paranoid? At least on Linux (Gnome), if I click to "safely remove drive" it actually powers off the drive and stops external mechanical drives from spinning. No useful syncing is going to happen anyway once a hard drive no longer spins. A modern OS should definitely be reliable enough that it can be trusted to properly unmount a drive.
> For the laptops that I actually carry around and plug and unplug things to etc, normal amount of time between reboots for me is somewhere between every 1 and 3 days. Cold boot is plenty fast anyway, so shutting it down after a day of work or when ejecting an external HDD or SSD doesn’t really cost me any noticeable amount of time.
I personally don't reboot my laptop that often, but it's not because of a boot taking too much time. It's because I like to keep state: open applications, open files, terminal emulator sessions, windows on particular virtual desktops, etc.
22:22:45 up 3748 days 21:20, 2 users, load average: 1.42, 1.36, 1.02
It's very funny, I think it's because my laptop battery died and when I replaced it, it had to update the time from 10 years ago? I'm not sure why, as the laptop is from mid-2012.
I thought I had a record going here with my Dell laptop, but I guess you win. After a certain point, I just decided to see how long I can make it go.
That's what the wiki says anyway: [1], and a publication with his name is about huge pages [2]
[1] https://wiki.freebsd.org/AlanCox
[2] https://www.usenix.org/legacy/events/osdi02/tech/full_papers...
You don't have to run the system for 50 days. You can simulate the environment and tick the clock faster. Many high reliability systems are tested this way.
If you wanted to see how time impacts the program, you'd prob change fns like calculate_tcp_clock to take uptime as an argument so that you could sanity check it.
At the very least, the writing takes way too long to get to a point.
these kernel versions:
Darwin Kernel Version 20.6.0: Thu Jul 6 22:12:47 PDT 2023; root:xnu-7195.141.49.702.12~1/RELEASE_ARM64_T8101 arm64
Darwin Kernel Version 17.7.0: Wed Apr 24 21:17:24 PDT 2019; root:xnu-4570.71.45~1/RELEASE_X86_64 x86_64
so... wonder what that's about?
tcp_now = 4,294,960,000 (frozen at pre-overflow value)
timer = 4,294,960,000 + 30,000 = 4,294,990,000
(exceeds uint32 max → wraps to a small number)
TSTMP_GEQ(4294960000, 4294990000)
= (int)(4294960000 - 4294990000)
= (int)(-30000)
= -30000 >= 0 ? → false!
There may be a short time period where this bug occurs, and if you get enough TCP connections to TIME_WAIT in that period, they could stick around, maybe. But I think the original post is completely overreacting and was probably written by a LLM, lol.
https://github.com/apple-oss-distributions/xnu/blame/f6217f8...
Edit: Actually looking at the older code, it looks like it may have the same problem on intel macs since timeval.tv_sec is a long and there's a comparison that doesn't handle it wrapping.
This is a weird thing to cite if it's a macOS 26 bug. I quite regularly go over 50 days of uptime without issues so it makes sense for it to be a new bug, and maybe they had different bugs in the past with similar symptoms.
Also, massively over-dramatised. Yes, a bug worth finding and knowing about, but it’s not a time bomb - very few users are likely to be affected by this.
Knowing the nature of OS kernels, I’m guessing even just putting a Mac laptop to sleep would be enough to avoid this issue as it would reset the TCP stack - which may be why some people are reporting much longer uptimes without hitting this problem, since (iirc) uptime doesn’t reset on Macs just for a sleep? Only for a full reboot?
Anyway, all in all, yeah hopefully Apple fix this but it’s not something anyone needs to panic about.
> We are actively working on a fix that is better than rebooting — a targeted workaround that addresses the frozen tcp_now without requiring a full system restart. Until then, schedule your reboots before the clock runs out.
God I wish Apple offered first party support for Linux on Mac computers.
loloquwowndueo•1h ago
ok123456•1h ago
aranelsurion•1h ago
loloquwowndueo•1h ago
flomo•52m ago
StilesCrisis•6m ago
larodi•1h ago
auspiv•1h ago
says 51 days, which would be an interesting number of (milli)seconds
otherme123•30m ago
znpy•43m ago