From: Andrew Morton <akpm@linux-foundation.org>
To: Dave Hansen <haveblue@us.ibm.com>
Cc: linux-kernel@vger.kernel.org, hch@infradead.org
Subject: Re: [PATCH 24/25] r/o bind mounts: track number of mount writers
Date: Mon, 24 Sep 2007 15:25:32 -0700 [thread overview]
Message-ID: <20070924152532.305ec951.akpm@linux-foundation.org> (raw)
In-Reply-To: <1190671602.26982.261.camel@localhost>
On Mon, 24 Sep 2007 15:06:42 -0700
Dave Hansen <haveblue@us.ibm.com> wrote:
> On Sun, 2007-09-23 at 23:17 -0700, Andrew Morton wrote:
> > It look like a false positive to me, but really, for a patchset of this
> > complexity and maturity I cannot fathom how it could have escaped any
> > lockdep testing.
>
> I test with lockdep all the time. The problem was that lockdep doesn't
> complain until you have 8 nested locks, and I only tested on a 4-cpu
> system.
>
> I lowered the lockdep nesting limit to 3, and got the warning on my
> machine.
>
hm. I saw that warning on my 2-way. It has CONFIG_NR_CPUS=8 so perhaps
the kernel has decided that this machine can possibly have eight CPUs.
It's an old super-micro board, doesn't have ACPI.
OEM ID: INTEL Product ID: 440BX APIC at: 0xFEE00000
Processor #0 6:8 APIC version 17
Processor #1 6:8 APIC version 17
I/O APIC #2 Version 17 at 0xFEC00000.
Enabling APIC mode: Flat. Using 1 I/O APICs
Processors: 2
...
Checking if this processor honours the WP bit even in supervisor mode... Ok.
Calibrating delay using timer specific routine.. 1707.03 BogoMIPS (lpj=3414067)
Mount-cache hash table entries: 512
CPU: After generic identify, caps: 0383fbff 00000000 00000000 00000000 00000000 00000000 00000000 00000000
CPU: L1 I cache: 16K, L1 D cache: 16K
CPU: L2 cache: 256K
CPU: After all inits, caps: 0383fbff 00000000 00000000 00000040 00000000 00000000 00000000 00000000
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#0.
Compat vDSO mapped to ffffe000.
Checking 'hlt' instruction... OK.
lockdep: not fixing up alternatives.
CPU0: Intel Pentium III (Coppermine) stepping 03
lockdep: not fixing up alternatives.
Booting processor 1/1 eip 2000
Initializing CPU#1
Calibrating delay using timer specific routine.. 1704.02 BogoMIPS (lpj=3408054)
CPU: After generic identify, caps: 0383fbff 00000000 00000000 00000000 00000000 00000000 00000000 00000000
CPU: L1 I cache: 16K, L1 D cache: 16K
CPU: L2 cache: 256K
CPU: After all inits, caps: 0383fbff 00000000 00000000 00000040 00000000 00000000 00000000 00000000
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#1.
CPU1: Intel Pentium III (Coppermine) stepping 03
Total of 2 processors activated (3411.06 BogoMIPS).
ExtINT not setup in hardware but reported by MP table
ENABLING IO-APIC IRQs
..TIMER: vector=0x31 apic1=0 pin1=2 apic2=0 pin2=0
APIC timer registered as dummy, due to nmi_watchdog=1!
checking TSC synchronization [CPU#0 -> CPU#1]: passed.
Brought up 2 CPUs
One would think that the kernel would work out that eight CPUs ain't
possible on such a machine. But we don't seem to print out any info which
allows me to confirm that this is really what the kernel did.
next prev parent reply other threads:[~2007-09-24 22:26 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-20 19:52 [PATCH 00/25] Read-only bind mounts Dave Hansen
2007-09-20 19:52 ` [PATCH 01/25] filesystem helpers for custom 'struct file's Dave Hansen
2007-09-20 19:52 ` [PATCH 02/25] rearrange may_open() to be r/o friendly Dave Hansen
2007-09-20 19:52 ` [PATCH 03/25] give may_open() a local 'mnt' variable Dave Hansen
2007-09-20 19:57 ` Christoph Hellwig
2007-09-20 19:52 ` [PATCH 04/25] create cleanup helper svc_msnfs() Dave Hansen
2007-09-20 19:52 ` [PATCH 05/25] r/o bind mounts: stub functions Dave Hansen
2007-09-20 19:52 ` [PATCH 06/25] elevate write count open()'d files Dave Hansen
2007-11-28 8:41 ` Andrew Morton
2007-11-28 17:33 ` Dave Hansen
2007-09-20 19:52 ` [PATCH 07/25] r/o bind mounts: elevate write count for some ioctls Dave Hansen
2007-09-21 8:17 ` Andrew Morton
2007-09-21 21:15 ` Dave Hansen
2007-09-26 1:34 ` [RFC] detect missed mnt_want_write() calls Dave Hansen
2007-09-21 23:03 ` [PATCH 07/25] r/o bind mounts: elevate write count for some ioctls Andrew Morton
2007-09-21 23:39 ` Dave Hansen
2007-09-21 23:47 ` Andrew Morton
2007-09-20 19:52 ` [PATCH 08/25] elevate writer count for chown and friends Dave Hansen
2007-09-20 19:53 ` [PATCH 09/25] make access() use mnt check Dave Hansen
2007-09-20 19:53 ` [PATCH 10/25] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2007-09-20 19:53 ` [PATCH 11/25] elevate write count during entire ncp_ioctl() Dave Hansen
2007-09-20 19:53 ` [PATCH 12/25] elevate write count for link and symlink calls Dave Hansen
2007-09-20 19:53 ` [PATCH 13/25] elevate mount count for extended attributes Dave Hansen
2007-09-20 19:53 ` [PATCH 14/25] elevate write count for file_update_time() Dave Hansen
2007-09-20 19:53 ` [PATCH 15/25] unix_find_other() elevate write count for touch_atime() Dave Hansen
2007-09-20 19:53 ` [PATCH 16/25] elevate write count over calls to vfs_rename() Dave Hansen
2007-09-20 19:53 ` [PATCH 17/25] nfs: check mnt instead of superblock directly Dave Hansen
2007-09-20 19:53 ` [PATCH 18/25] elevate writer count for do_sys_truncate() Dave Hansen
2007-09-20 19:53 ` [PATCH 19/25] elevate write count for do_utimes() Dave Hansen
2007-09-20 19:53 ` [PATCH 20/25] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2007-09-20 19:53 ` [PATCH 21/25] sys_mknodat(): elevate write count for vfs_mknod/create() Dave Hansen
2007-09-20 19:53 ` [PATCH 22/25] elevate mnt writers for vfs_unlink() callers Dave Hansen
2007-09-20 19:53 ` [PATCH 23/25] do_rmdir(): elevate write count Dave Hansen
2007-09-20 19:53 ` [PATCH 24/25] r/o bind mounts: track number of mount writers Dave Hansen
2007-09-24 6:17 ` Andrew Morton
2007-09-24 14:34 ` Arjan van de Ven
2007-09-24 22:06 ` Dave Hansen
2007-09-24 22:25 ` Andrew Morton [this message]
2007-09-24 23:05 ` Dave Hansen
2007-09-24 23:15 ` Andrew Morton
2007-09-25 16:10 ` Dave Hansen
2007-09-24 17:54 ` Christoph Hellwig
2007-09-24 19:10 ` Andrew Morton
2007-09-24 19:24 ` Christoph Hellwig
2007-09-24 19:28 ` Dave Hansen
2007-09-24 19:42 ` Andrew Morton
2007-10-01 18:06 ` Dave Hansen
2007-09-20 19:53 ` [PATCH 25/25] honor r/w changes at do_remount() time Dave Hansen
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