and I'd really like people to give it a good testing: especially if you've
seen slow network connections to some clients (ie Windows). David worked
in the compatibility patches to work around some of the Windows TCP stack
"features" (and Apple too, for that matter), and we want to get this well
tested. It's all fairly straightforward, but let's be careful out there..

                Linus

I made Linux-2.2.5 yesterday (as some people already have noticed: due to
popular demand I try to delay the announcement for some time in order to
let the thing percolate to mirror sites, in case anybody wondered).
The 2.2.5 release is meant to be a final cleanup release before I leave
for a two-week vacation. So please take these release notes to also mean
that it is probably a good idea to hold off emailing me stuff directly,
unless it is a major bug that you really think I should look at
immediately. I would suggest people discuss problems on the mailing list
and on the newsgroups, where other competent people are, rather than
expecting me to do much about it.

Also, note that there have been various indications that egcs potentially
miscompiles the kernel, or at least makes some problems worse. We don't
know whether that is due to one or more kernel bugs, compiler problems, or
just combinations of "features" in both. I would suggest that if you have
problems you at least verify whether the problems still exist with
gcc-2.7.2.

That said, I bet that both the kernel people and the egcs people would be
really happy the more people look into this - if somebody feels motivated
enough and sees problems with egcs, it would be extremely powerful to try
to pinpoint the particular file that seems to bring on the problems. I'm
afraid it needs a known failure mode and lots of legwork to find out what
triggers it, though.

 - compiles with accounting.
 - add support for Microgate SyncLink and Synchronous HDLC
 - stallion driver update
 - alpha EV6 and SMP fix for bootup with newer compilers
 - ptrace fix for sparc/i386
 - small sparc updates
 - floppy driver could oops at bootup under certain setups
 - random driver updates (bw-qcam, sound driver error codes, etc oneliners)
 - FIOASYNC ioctl fix
 - network locking fixes
 - SMP "struct user" and signal sending fixes

Have fun, because I will,

                        Linus

As of 2.2.4, I should be synchronized with the Sparc[64] and PPC ports,
which is the major reason why the patch is pretty huge. Apart from the
architecture synchronizations, 2.2.4 does:

 - dumping core over NFS could do bad things. Core-dumping cleaned up and
   fixed.

 - various small TCP/IP buglets fixed. Linux got confused by hosts that
   didn't report any mss, and had problems with zero-sized fragments, etc.

 - various small, often silly bugs fixed (PC BIOS PCI buglet, alpha
   semaphores, bottom half interrupts, fork() returns wrong error code).

 - tons of driver updates

 - updated net scheduling code (CONFIG_NET_SCHED)

Most of the fixes aren't all that noticeable, but some of them can be
showstoppers depending on whether you've ever seen them.

There's a new pre-patch for 2.2.3, one that I was already going to make
the final 2.2.3, but I decided that I'm chicken after all, and that I
might as well let some people check that it's sane.
This pre-2.2.3 does:

 - Fix some silly NFS problems. Some of them can be quite bad: lost error
   notification of asynchronous writes, which can result in horrible
   problems (including lost email etc). Most people wouldn't ever notice,
   so don't panic, but forgetting about the error notification certainly
   counts as a brown paper bag.
 - Alpha should compile and work again
 - Various driver updates. This is actually the bulk of the patch, with
   IRDA updates, some scsi, video and sound driver updates etc.
 - The "mmap forgets about the file that was mapped" bug that has been
   discussed here. Only affected certain drivers.
 - shaper atomicity fixes
 - various minor TCP fixes
 - buffer growth fix and recursive IO memory reclaim fix from Andrea
 - network filter compiles ;)
 - unix gc fixes

Tell me if you see problems, because I'm going to release it as 2.2.3
unless people tell me otherwise..

                Linus

In a superhuman effort to not get killed by my wife, I delayed the latest
release for a day. And in fact, it's still just a pre-release, because I
wanted to check with Ingo that I have his latest IO-APIC code with the
proper handling of ExtINT. Ingo?

Anyway, the "not quite valentine days release" (also known as the "horny
greased weasel", aka "presidents day" release ;), is right now a pre-patch
on ftp.kernel.org: /pub/linux/kernel/testing/pre-patch-2.2.2-4.gz.

Happily, I haven't heard of any new real show-stoppers, which is good
(especially considering the fact that I gave it an extra week just to hear
if somebody could come up with some new problems). The things fixed
relative to 2.2.1 are:

 - the inode thing. If you don't know, don't worry.
 - config scripts updated
 - IO-APIC cleanups and fixes, so that people with strange motherboards
   should be able to reboot cleanly and not get unexpected interrupts.
 - 2kB sector media (ie mostly MO) fixes. See all the warnings on the
   lists about fdisk confusion etc if you have one of these things.
 - IDE disk cleanups/fixes (geometry and autodetection)
 - PS/2 mouse hides ACK's again
 - pty crash fix
 - some network driver fixes (out-of-memory and shared interrupts)
 - some sound and video updates.
 - lockd cookie fixes
 - nfsd readdir reply cache fix
 - filesystem/VM deadlock avoidance (new deamon: kpiod)
 - SMP scheduler race condition (which nobody has probably ever seen)
 - TCP socket locking fix

Most of the above are really hard to see in the first place, and not
something most people would ever hit (with the possible exception of the
inode thang).  But it would be good to have a really rock solid 2.2.2, so
if people could just bother to check that it works for them, and I'll make
this official tomorrow.

                Linus

this one contains various small documentation updates and updates to xconfig,
but the important parts (and the smallest part of the actual patch) are:

 - shared file lockup fix by Stephen Tweedie
 - my fix for the TCP bug that Ingo found
 - Ingo's io-apic setup fixes, which should finally get rid of the
   spurious apic interrupts with some motherboards and the ExtINT setup.
 - inode leak thing
 - SMP scheduler potential race condition fix
 - sound driver updates
 - partition and disk fixes (2kB blocksize media and some IDE disk
   geometry and irq detection issues).

None of the fixes are critical to most people, but all of them _can_ be
critical to people who have seen vulnerabilities in the area. As such, if
you're happy with 2.2.1 there is no pressing reason to test this patch
out, but I hope to have the pre-patches so that the final 2.2.2 can be
left around for a while (CD-ROM manufacturers etc would certainly prefer
to not see lots of releases).

                Linus

The subject says it all. We did have a few paper-bag-inducing bugs in
2.2.0, so there's a 2.2.1 out there now, just a few days after 2.2.0.
Oh, well. These things happen,

                Linus

- the stupid off-by-one bug 'execute a coredump' crash found by Ingo
- __down_interruptible on alpha
- move "esstype" to outside a #ifdef MODULE
- NFSD rename/rmdir fixes
- revert to old array.c
- change comment about __PAGE_OFFSET
- missing "vma = NULL" case for avl find_vma()

> Compile this code
>
> ---- cut here ----
> #include <fcntlbits.h>
> void main( int argc, char *argv[] ) {
>         open( argv[ 1 ], O_WRONLY|O_CREAT|O_TRUNC, 0666 );
> }
> ---- and here  ----
>
> and run it like this
>
>     strace ./a.out >(cat - )
>
> with 2.0.36 & 2.2.0-pre[67] you get:
>
>     open("/dev/fd/63", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3
>
> with 2.2.0-pre[89] you get:
>
>     open("/dev/fd/63", O_WRONLY|O_CREAT|O_TRUNC, 0666) = -1 ENOENT (No
> such file or directory)

Ok, this seems to be due to pre9 removing some rather bogus code that
happened to hide another problem in open_namei().
I haven't actually tested this, but it looks really obvious, so does this
patch fix it for you? (This should also fix a potential performance
bogosity - there's absolutely no reason why we should get the directory
lock when we don't need to for a normal open of an existing file).

                Linus

Hoya,
 there's now a 2.2.0-pre9 on ftp.kernel.org, and when you compile it it
will call itself 2.2.0-final. The reason is fairly obvious: enough is
enough, and I can't make pre-kernels forever, it just dilutes the whole
idea. The only reason the tar-file is not called 2.2.0 is that I want to
avoid having any embarrassing typos that cause it to not compile under
reasonable configurations or something like that. Unreasonable
configurations I no longer care about.

Every program has bugs, and I'm sure there are still bugs in this. Get
over it - we've done our best, and nobody ever believed that there
wouldn't be 2.2.x kernels to fix problems as they come up, and delaying
2.2.0 forever is not an option.

I have a wedding anniversary and a company party coming up, so I'm taking
a few days off - when I get back I expect to take this current 2.2.0-final
and just remove the "-final" from the Makefile, and that will be it. I
suspect somebody _will_ find something embarrassing enough that I would
fix it too, but let's basically avoid planning on that.
In short, before you post a bug-report about 2.2.0-final, I'd like you to
have the following simple guidelines:
 "Is this something Linus would be embarrassed enough about that he would
  wear a brown paper bag over his head for a month?"
and
 "Is this something that normal people would ever really care deeply
  about?"

If the answer to either question is "probably not", then please consider
just politely discussing it as a curiosity on the kernel mailing lists
rather than even sending email about it to me: I've been too busy the last
few weeks, and I'd really appreciate it if I could just forget the worries
of a release for a few days..

But if you find something hilariously stupid I did, feel free to share it
with me, and we'll laugh about it together (and I'll avoid wearing the
brown paper bag on my head during the month of February). Do we have a
deal?

I've seen people working on a 2.2.0 announcement, and I'm happy - I've
been too busy to think straight, much less worry about details like that.
If everything turns out ok, I'll have a few memorable bloopers in my
mailbox but nothing worse than that, and I can sit down and actually read
the announcement texts that people have been discussing.

ObFeatures:
 - m68k sync
 - various minor driver fixes (irda, net drivers, scsi, video, isdn)
 - SGI Visual Workstation support
 - adjtimex update to the latest standards
 - vfat silly buglet fix
 - semaphores work on alpha again
 - drop the inline strstr() that gcc got wrong whatever we did
 - kswapd needed to be a bit more aggressive
 - minor TCP retransmission and delack fixes
Until Monday,
                        Linus

Ok, I think I now know why pre-6 looks so unbalanced. It's two issues.
Basically, trying to swap out a large number of pages from one process
context is just doomed. It bascially sucks, because

 - it has bad latency. This is further excerberated by the per-process
   "thrashing_memory" flag, which means that if we were unlucky enough to
   be selected to be the process that frees up memory, we'll probably be
   stuck with it for a long time. That can make it extremely unfair under
   some circumstances - other processes may allocate the pages we free'd
   up, so that we keep on being counted as a memory trasher even if we
   really aren't.
   Note that this shows most under "moderate" load - the problem doesn't
   tend to show itself if you have some process that is _really_
   allocating a lot of pages, because then that process will be correctly
   found by the trashing logic. But if you have lots of "normal load"
   processes, some of those can get really badly hurt by this.
   In particular, the worst case you have a number of processes that all
   allocate memory, but not very quickly - certainly not more quickly than
   we can page things out. What happens is that under these circumstances
   one of them gets marked as a "scapegoat", and once that happens all the
   others will just live off the pages that the scapegoat frees up, while
   the scapegoat itself doesn't make much progress at all because it is
   always just freeing memory for others.
   The really bad behaviour tends to go away reasonably quickly, but while
   it happens it's _really_ unfair.
 - try_to_free_pages() just goes overboard, and starts paging stuff out
   without getting back to the nice balanced behaviour. This is what
   Andrea noticed.
   Essentially, once it starts failing the shrink_mmap() tests, it will
   just page things out crazily. Normally this is avoided by just always
   starting from shrink_mmap(), but if you ask try_to_free_pages() to try
   to free up a ton of pages, the balancing that it does is basically
   bypassed.

So basically pre-6 works _really_ well for the kind of stress-me stuff
that it was designed for: a few processes that are extremely memory
hungry. It gets close to perfect swap-out behaviour, simply because it is
optimized for getting into a paging rut.

That makes for nice benchmarks, but it also explains why (a) sometimes
it's just not very nice for interactive behaviour and (b) why it under
normal load can easily swap much too eagerly.

Anyway, the first problem is fixed by making "trashing" be a global flag
rather than a per-process flag. Being per-process is really nice when it
finds the right process, but it's really unfair under a lot of other
circumstances. I'd rather be fair than get the best possible page-out
speed.

Note that even a global flag helps: it still clusters the write-outs, and
means that processes that allocate more pages tend to be more likely to be
hit by it, so it still does a large part of what the per-process flag did
- without the unfairness (but admittedly being unfair sometimes gets you
better performance - you just have to be _very_ careful whom you target
with the unfairness, and that's the hard part).

The second problem actually goes away by simply just not asking
try_to_free_pages() to free too many pages - and having the global
trashing flag makes it unnecessary to do so anyway because the flag will
essentially cluster the page-outs even without asking for them to be all
done in one large chunk (and now it's not just one process that gets hit
any more).

There's a "pre-7.gz" on ftp.kernel.org in testing, anybody interested?
It's not the real thing, as I haven't done the write semaphore deadlock
thing yet, but that one will not affect normal users anyway so for
performance testing this should be equivalent.

                        Linus

Oh, well.. Based on what the arca-[678] patches did, there's now a pre-5
out there. Not very similar, but it should incorporate the basic idea:
namely much more aggressively asynchronous swap-outs from a process
context.
Comment away,
                Linus

Ok, you know the drill by now. This fixes:
 - yes, people told me about the new and improved ksymoops. Much better,
   no need for C++, and this one actually seems to compile and work
   reliably.
 - ntfs fixes
 - the vfat thing _really_ works now
 - NFS fix for deleting files while writebacks active.
 - ppa/imm driver updated
 - minor mm balancing patches
 - Alan took the gauntlet and cleaned up some CONFIG_PROC_FS stuff.
More on Monday,

                Linus

Well, some people obviously had problems with the first 2.2.0pre, so
there's a second one there. Most of it is almost purely syntactic sugar:
configuration issues and jiffies wraparound, but there were a few problems
wrt some IDE disk geometry stuff in particular that made 2.2.0pre1 not
boot for some people.

Other real changes:
 - nfsd updated, and we have an official maintainer for knfsd (and I was
   happy by how many people were ready to stand up for it. Good show,
   guys!)
 - network driver updates (tulip/eepro)
 - some TCP fixes for occasional but nasty performance problems.
 - fix for an attack where you could cause a complete and utter lockup of
   the kernel as a normal user. Thanks to Michael Chastain for keeping the
   faith on this one and reminding me to fix it.

If you haven't had problems with pre1, there should be no major cause to
look at pre2. But if you haven't even looked at pre1 yet, please consider
looking at the pre-2.2.0 kernels before it's too late. I'm going to be
extremely rude to people who knew better but didn't test out the pre-
kernels and then send me bug-reports on the released 2.2.0.

		Linus

 we're in the pre-2.2.0 series now, I'm all synched up with Alan, and I
don't have anything pending any more. Over the internet nobody can hear
you all scream in pain over all your favourite features that didn't make
it.

	Linus "another year older and wise as hell by now" Torvalds

There's a new pre-patch on ftp.kernel.org. I've been waiting for a few
other things, but the pre-patches are getting to be so big that it's
getting unwieldly, so I'll probably make a real 2.1.132 real soon now. In
the meantime, there's a pre-patch that people can verify for sanity (this
one should have coda-fs back to working order, for example - patch
craziness corrupted a simple update in pre-3).

                Linus