Linux 2.4.21-rc7
----- Original Message -----
From: Willy Tarreau <[email protected]>
Date: Sun, 8 Jun 2003 11:47:29 +0200
To: Clayton Weaver <[email protected]>
Subject: Re: Linux 2.4.21-rc7
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Hi !
Greets.
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[ first, please fix your mailer and cut your lines, it's not easy to quote you in replies ]
Long lines?
email.com is a web mailer. If it is failing to wrap where I put newlines, I'll see what I can do.
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Now I really hope its the last one, all this
rc's are making me mad.We still have ide problems, and I don't see
any
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potential fixes for that in the changelog between -rc6 and -rc7.
I tried -rc6 on a whim and had hda report
a timeout (dma, I think, but the message went by kind of quick), then the big freeze with the disk light stuck on, Never happened in 6 months on the same hardware running 2.4.19-rc2 (with glibc-2.2.5, gcc-2.95.3, binutils-2.12.90.0.9, all ext2 filesystems).Did you try with "ide0=nodma", or other similar options ?
No.
Note that "nodma" is unnecessary on this same box running kernel 2.4.19-rc2. Why would 2.4.21-rcX need it? To pin down whether the problem is in the ide dma code or some other part of the ide code?
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SiS530/5513, k6-II/450, udma33 Maxtor
drivethat 2.4.19-rc2 has no problems with.
Here is the data on the drive from hdparm while running under 2.4.19-rc2. rc.local executes "hdparm -c 1 /dev/hda" at boot.
hdparm -v:
/dev/hda:
multcount = 16 (on) IO_support = 1 (32-bit) unmaskirq = 0 (off) using_dma = 1 (on) keepsettings = 0 (off) readonly = 0 (off) readahead = 8 (on)
geometry = 1655/255/63, sectors = 26588016, start = 0
hdparm -i:
/dev/hda:
Model=Maxtor 91360U4, FwRev=MA540RR0, SerialNo=C40LMAFC Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57 BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=26588016 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120} PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 *udma2
AdvancedPM=yes: disabled (255) WriteCache=enabled
Drive conforms to: ATA/ATAPI-4 T13 1153D revision 17: 1 2 3 4 5
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That's not exactly what you said below. You said that you could reliably kill it with 32 threads... Perhaps you have a broken hardware, and 2.4.21 stresses it more than 2.4.19-rc2. Perhaps it's really an old driver bug, then having reported it since this you encountered it would have been more constructive than telling us at 2.4.21 time that it dies even more easily than a one year old 2.4.19-rc2.
It does not die more easily with 2.4.19-rc2 (in my opinion). It dies in a threads context but not in a forks context, where the threads and the forks are doing the same i/o to/from the same controller/disk (different versions of same program).
I have also seen it freeze with an unlucky mouse click in XFree86 4.0 under 2.4.19-rc2, so I did not assume that the threads hang was necessarily ide-relevant. Something disk i/o intensive was merely what it happened to be doing with those threads, but that problem seemed to me more thread related than ide related. (Guess I'll have to spawn a bunch of threads doing some other kind of i/o to test that assumption.)
[]
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(Better to find out sooner than release
2.4.21-stable and watch 52 different bug reports on it arrive at the list the next day.)Well, look through the archives, there have been two patches by Lionel Bouton and Vojtech Pavlik posted in May for the 5513 driver, to support newer chipsets. I don't know if they have been included, nor if they also fixed old bugs. Perhaps you'll be intersted in checking them.
(SiS530 is not newer, k6-II era, but it is worth a look anyway.)
The SiS5513 driver seems fine. You can
hammer on it all day with this motherboard
with gcc, multiple smb mounts, gigabyte ftp or
sftp transfers, etc, in parallel, and no blinks from the hard drive (modulo threads or the X-server under 2.4.19-rc2).
(Why 2.4.19-rc2? It mostly works, ie it is
stable for what I typically use that box
for. Someone running a different application
mix or different hardware might consider it useless crap. It has the lcall fix and a few other minor bug fixes that were posted
to the kernel list between then and now.)
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BTW, someone reported yesterday that his 5513 worked flawlessly in 2.4.20, but behaved like yours on 2.5.70. Have you tested 2.4.20, or better, have you tried to narrow the problem down to a particular version (but I bet it will be tied to the introduction of the newer IDE code).
No. (I do actually need this thing to work at times.) The newer ide code as the source of the problem matches my hunch. Maybe the kernel debugging that I enabled at compile time will come up with something (*before* the deadlock, so it can actually log an anomaly).
The newer ide code may have found a bug in the SiS5513 driver that the old code did not exercise. Let us hope not, because then a fix only fixes it for me and other users of that driver, while lots of people with other kinds of ide hardware seem to be reporting similar problems.
My guess is that the problems are upstream of any specific driver, but that is merely a hunch. (It is possible that they all do the same wrong thing *in the drivers*.)
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You may also try -ac kernels which have more recent, but less tested code.
Regards,
Willy
Thanks for the insight.
Regards,
Clayton Weaver
<mailto: [email protected]>
Signature · 3 lines
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Please stop comparing 2.4.19-rc2 to 2.4.21-rc7. Just go through 2.4.20-pre/-rc and 2.4.21-pre/-rc and find when things broke if you want them fixed. --
Bartlomiej
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Note that "nodma" is unnecessary on this same box running kernel 2.4.19-rc2. Why would 2.4.21-rcX need it? To pin down whether the problem is in the ide dma code or some other part of the ide code?
exactly, because DMA needs more conditions than PIO to run at all and even more to run reliably. There are lots of cases where DMA doesn't work while PIO does.
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It does not die more easily with 2.4.19-rc2 (in my opinion). It dies in a threads context but not in a forks context, where the threads and the forks are doing the same i/o to/from the same controller/disk (different versions of same program).
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I have also seen it freeze with an unlucky mouse click in XFree86 4.0 under 2.4.19-rc2, so I did not assume that the threads hang was necessarily ide-relevant. Something disk i/o intensive was merely what it happened to be doing with those threads, but that problem seemed to me more thread related than ide related. (Guess I'll have to spawn a bunch of threads doing some other kind of i/o to test that assumption.)
OK, but a freeze isn't acceptable anyway, whatever you were doing, because it always means a bug somewhere.
Cheers,
Willy
PS: your lines were shorter this way :-)