On Tue, Jul 20, 2004 at 09:39:21AM -0500, Jeffrey E. Hundstad wrote:
> Steve Lord wrote:
> >Don't use 4K stacks and XFS. What you hit here is a path where the
> >filesystem is getting full and it needs to free some reserved space
> >by flushing cached data which is using reserved extents. Reserved
> >extents do not yet have an on disk address and they include a
> >reservation for the worst case metadata usage. Flushing them will
> >get you room back.
> >As you can see, it is a pretty deep call stack, most of XFS is going
> >to work just fine with a 4K stack, but there are end cases like
> >this one which will just not fit.
> If this is a known truth with XFS maybe it would be a good idea to have
> 4K stacks and XFS be an impossible combination using the config tool.
The patch below does:
1. let 4KSTACKS depend on EXPERIMENTAL
4Kb stacks on i386 are the future. But currently this option might still
cause problems in some areas of the kernel. OTOH, 4Kb stacks isn't a big
gain for most people.
2.6 is a stable kernel series, and 4KSTACKS=n is the safe choice.
Once all issues with 4KSTACKS=y are resolved this can be reverted.
2. let XFS depend on (4KSTACKS=n || BROKEN)
Mark Loy said:
Don't use 4K stacks and XFS.
Mark this combination as BROKEN until XFS is fixed.
This might result in XFS support disappearing for some people, but if
they use EXPERIMENTAL=y they should know what they are doing.
The 4KSTACKS option has to be moved for that it's asked before XFS in
arch/i386/Kconfig | 19 ++++++++++---------
fs/Kconfig | 1 +
2 files changed, 11 insertions(+), 9 deletions(-)
Signed-off-by: Adrian Bunk <bunk@xxxxxxxxx>
--- linux-2.6.8-rc2-full/arch/i386/Kconfig.old 2004-07-20 21:00:32.000000000
+++ linux-2.6.8-rc2-full/arch/i386/Kconfig 2004-07-20 21:03:30.000000000
@@ -865,6 +865,16 @@
generate incorrect output with certain kernel constructs when
-mregparm=3 is used.
+ bool "Use 4Kb for kernel stacks instead of 8Kb"
+ depends on EXPERIMENTAL
+ If you say Y here the kernel will use a 4Kb stacksize for the
+ kernel stack attached to each process/thread. This facilitates
+ running more threads on a system and also reduces the pressure
+ on the VM subsystem for higher order allocations. This option
+ will also use IRQ stacks to compensate for the reduced stackspace.
@@ -1289,15 +1299,6 @@
If you don't debug the kernel, you can say N, but we may not be able
to solve problems without frame pointers.
- bool "Use 4Kb for kernel stacks instead of 8Kb"
- If you say Y here the kernel will use a 4Kb stacksize for the
- kernel stack attached to each process/thread. This facilitates
- running more threads on a system and also reduces the pressure
- on the VM subsystem for higher order allocations. This option
- will also use IRQ stacks to compensate for the reduced stackspace.
depends on X86_LOCAL_APIC || X86_VOYAGER
--- linux-2.6.8-rc2-full/fs/Kconfig.old 2004-07-20 21:04:02.000000000 +0200
+++ linux-2.6.8-rc2-full/fs/Kconfig 2004-07-20 21:04:25.000000000 +0200
@@ -294,6 +294,7 @@
tristate "XFS filesystem support"
+ depends on (4KSTACKS=n || BROKEN)
XFS is a high performance journaling filesystem which originated
on the SGI IRIX platform. It is completely multi-threaded, can