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FreeBSD 4 Bug may be present in Playstation 4/5

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Re: FreeBSD 4 Bug may be present in Playstation 4/5

#31

Post by tiffanyh »

znpy wrote: post #18
makeitdouble wrote: post #17

Earlier quoted context omitted.

That's also the period Yahoo and other companies had a tremendous investment in FreeBSD. FreeBSD is great on its own, and that amount of attention also meant every single bit of performance would be extracted no matter what it takes, and any scaling or stability issues would be hammered out pretty quick. Until they moved to redhat...

> Until they moved to redhat... Does anybody know why they switched to RedHat ?

This old thread has former Y! folks chiming in as to why.

https://news.ycombinator.com/item?id=10558288

> I think the justifications were better support for running on Linux (storage drivers, Java, MySQL, oracle), better support for virtualization (although bsd jails are better than virtualization in my opinion, and a better fit for Y!), and it would be easier to support one os instead of two and acquisitions (including inktomi) really wanted to run on Linux.

Re: FreeBSD 4 Bug may be present in Playstation 4/5

#32

Post by yjftsjthsd-h »

SomeoneFromCA wrote: post #12
hn8305823 wrote: post #11

Earlier quoted context omitted.

I've only ever lost data on Linux ext* filesystems, never on FreeBSD UFS or ZFS. 20 years ago it was unfortunately not unusual to experience the Linux "nuclear fsck" where it scrolls by so fast and for so long you know it's toast.

Hell no. I worked in an ISP in late 90s. NTFS was absolutely rock reliable, then (much worse)ext2, then (slightly worse) UFS, and then FAT.

20 years ago is 2004, not the 90s. I don't know, but it's certainly possible that one of them was in the lead in 1995, a different one in 2005, and a different one in 2015. This is especially plausible because Linux was only created in the mid 90s, so those first few years seem likely to have been disproportionately rough.

Re: FreeBSD 4 Bug may be present in Playstation 4/5

#33

Post by throwaway71271 »

tiffanyh wrote: post #15
throwaway71271 wrote: post #4

Earlier quoted context omitted.

yea: https://lists.freebsd.org/pipermail/freebsd-current/2003-Jul...

DragonflyBSD is typically on-par or slightly faster than Ubuntu (Linux) or FreeBSD. And that's with a radically smaller # of developers working on it. https://www.phoronix.com/review/corei9-freebsd13-dfly6/4 -- Yes, I know the common complaint is benchmarks are flawed and how Phoronix could do more meaningful test. But the reality is, nearly no one even does comprehensive OS benchmarking anymore - so there isn't real…

In the very beginning I think they(df) used pgbench kind of benchmarks 'the smp' benchmark, as a lot of people were using postgres and was really easy to compare qps and transactions per second, of course it also tests ufs2 vs hammer. (if I remember correctly)

It was a long time ago, but freebsd5 felt more like a new OS than just a 4.11->5.0 bump, particularly with the removal of the giant lock and all the witness(4) work, took a while to figure out how to finetune it as a lot of systems were giant free but not all, and also of course moving one lock to many small locks means a lot of spinning and certain patterns of workloads are slower than before. It took until 7.0 to get amazing, and then in 8 or so I think it was super solid.

Dragonfly went with kernel messaging and one scheduler per core, and FreeBSD spent a lot of time into making a preemptive scheduler (sched_ule (4) : http://fxr.watson.org/fxr/source/kern/sched_ule.c?v=FREEBSD-...)

Weird times, but I am super grateful that both the FreeBSD team and the DragonflyBSD team did what they think is right.

Mad respect to the people who are just coding what they think is right.

Re: FreeBSD 4 Bug may be present in Playstation 4/5

#34

Post by retrac »

adrian_b wrote: post #10
tiffanyh wrote: post #2

FreeBSD 4.x was considered by many as the most stable FreeBSD ever. Mainly because there were 11 point releases of fixes and enhancements (4.11), as opposed to today where FreeBSD major version only have 3-4 point releases. https://www.freebsd.org/releases/

It was not only the most stable, but for many applications, especially in networking, it was also the fastest single-threaded operating system, beating easily Linux and Windows XP or 2000. Unfortunately for FreeBSD, the launch of the Intel Pentium 4 with hyper-threading in 2003, then of the AMD dual-core CPUs in 2005 have made quickly FreeBSD 4 completely obsolete. The smaller FreeBSD team has required many years unt…

> required many years until achieving a decent implementation for multi-threaded CPUs and during that time they have remained long behind Linux and other operating systems

Many OSes at the time had hitches with SMP. BSD was one of them. FreeBSD had SMP in 4.x but almost everything in the kernel was single-threaded and the kernel thread was a major bottleneck.

FreeBSD wasn't alone in this. Linux suffered from a similar problem at the time, also because of the driver architecture. (The infamous "big kernel lock" wasn't fully eliminated until 2011: https://kernelnewbies.org/BigKernelLock)

This is an area where NT was much better, or VMS, or Solaris. And yes, the SMP issue, in hindsight, does partly explain why both Linux and BSD weren't as historically attractive as they otherwise looked, for large systems.

Re: FreeBSD 4 Bug may be present in Playstation 4/5

#35

Post by WhereIsTheTruth »

speps wrote: post #6
WhereIsTheTruth wrote: post #5

Time to buy a PS5 before this gets patched!

It's already patched: > Early tests seem to indicate that a crash is indeed present in PS4 up to 11.00 included, and PS5 8.20 included. (Which would put the patch for this issue at firmwares PS5 8.40 and PS4 11.02)

Not the ones sitting in the store

Re: FreeBSD 4 Bug may be present in Playstation 4/5

#36

Post by MuffinFlavored »

speps wrote: post #6
WhereIsTheTruth wrote: post #5

Time to buy a PS5 before this gets patched!

It's already patched: > Early tests seem to indicate that a crash is indeed present in PS4 up to 11.00 included, and PS5 8.20 included. (Which would put the patch for this issue at firmwares PS5 8.40 and PS4 11.02)

I wonder if that's how the "hacker community" knew to look for it, doing a diff of what gets "flashed" 8.20 -> 8.40?

Re: FreeBSD 4 Bug may be present in Playstation 4/5

#37

Post by adrian_b »

mysteria wrote: post #30
hn8305823 wrote: post #11

Earlier quoted context omitted.

I've only ever lost data on Linux ext* filesystems, never on FreeBSD UFS or ZFS. 20 years ago it was unfortunately not unusual to experience the Linux "nuclear fsck" where it scrolls by so fast and for so long you know it's toast.

I've 100% had issues with UFS, it's a simple filesystem and subsceptible to corruption. ZFS meanwhile is a different beast altogether which is designed to ensure data integrity at all costs.

UFS without soft updates is easily susceptible to corruption.

The "soft updates" option must be chosen when the disk is formatted for good reliability.

As I have said, 20 years ago "soft updates" in UFS worked better than journaling in the other contemporaneous file systems.

Nowadays it is likely that this is no longer true. I am still using FreeBSD in servers, but unlike 20 years ago I can afford UPSes so I no longer see often crashes due to power outages, even if I had one incident some time ago with a battery that had not been replaced yet after the UPS had warned that this is necessary, and when a power outage happened, the UPS worked for less than a minute and the power was cut before system shutdown. Even in this case there was no file system corruption on UFS.

Even with this good recent experience, today I would no longer trust UFS like 20 years ago, because it is said the current FreeBSD maintainers no longer understand the convoluted code that implements "soft updates" in UFS, and in any case most of their file system maintenance and development work is directed at ZFS now.

Re: FreeBSD 4 Bug may be present in Playstation 4/5

#38

Post by sjsdaiuasgdia »

SomeoneFromCA wrote: post #24
dewey wrote: post #21

Earlier quoted context omitted.

Sounds more likely that your OS just had less things going on and your browser not as many extensions running as your daily driver browser.

No, not really. I have many old Linux VMs too, with different degree of rot, and FreeBSD has noticeable smaller tcp connection establishment latency. Youtube opens way faster than on both older and newer linux vms.

The issue is that you're performing a test which involves a whole bunch of interconnected layers and then assigning one part of that interconnected system as where the benefits lie.

Why not the TLS implementation? The video drivers and their kernel interfaces? The OS' process scheduling? A dozen other things that might be responsible for the perceived performance difference to one degree or another?

It feels like gamers who blame 90% of multiplayer issues on "the netcode".

It'd be different with data looking specifically at TCP connection establishment timing without a bunch of other stuff involved.

Re: FreeBSD 4 Bug may be present in Playstation 4/5

#39

Post by adrian_b »

SomeoneFromCA wrote: post #12
hn8305823 wrote: post #11

Earlier quoted context omitted.

I've only ever lost data on Linux ext* filesystems, never on FreeBSD UFS or ZFS. 20 years ago it was unfortunately not unusual to experience the Linux "nuclear fsck" where it scrolls by so fast and for so long you know it's toast.

Hell no. I worked in an ISP in late 90s. NTFS was absolutely rock reliable, then (much worse)ext2, then (slightly worse) UFS, and then FAT.

NTFS might have been rock reliable in Windows NT and perhaps also in Windows 2000.

When Windows XP has been launched, NTFS was certainly much less reliable. Even without being affected by any crashes or other anomalies, the free space on the NTFS partitions of early Windows XP computers would shrink steadily, without any apparent cause, requiring a reformatting/reinstallation after some time.

Early Windows XP was very buggy. While a computer with Windows XP did not require one or more reboots per day like one with Windows 98, failing to reboot it for more than a few days guaranteed a crash.

Only after installing several massive service packs in the following years, Windows XP has become reasonably stable.

Re: FreeBSD 4 Bug may be present in Playstation 4/5

#40

Post by throw0101d »

adrian_b wrote: post #37
mysteria wrote: post #30

Earlier quoted context omitted.

I've 100% had issues with UFS, it's a simple filesystem and subsceptible to corruption. ZFS meanwhile is a different beast altogether which is designed to ensure data integrity at all costs.

UFS without soft updates is easily susceptible to corruption. The "soft updates" option must be chosen when the disk is formatted for good reliability. As I have said, 20 years ago "soft updates" in UFS worked better than journaling in the other contemporaneous file systems. Nowadays it is likely that this is no longer true. I am still using FreeBSD in servers, but unlike 20 years ago I can afford UPSes so I no longe…

A journal(-like) mechanism was added to soft-upates by McKusick in the 2010 timeframe:

* https://www.youtube.com/watch?v=_NuhRkiInvA (BSDCan)

* https://www.mckusick.com/softdep/suj.pdf

Which also allows snapshots:

* https://freebsdfoundation.org/project/snapshots-on-filesyste...

See also "Journaling versus Soft Updates: Asynchronous Meta-data Protection in File Systems":

* https://www.seltzer.com/assets/publications/Journaling-versu...

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