into penguin.transmeta.com:/home/penguin/torvalds/repositories/kernel/linux

- irq handlers should be cache-affine to a large degree, without the
  explicit use of /proc/irq/*/smp_affinity.

- idle CPUs should be preferred over busy CPUs when directing IRQs towards
  them.

- the distribution of IRQs should be random, to avoid all IRQs going to
  the same CPU, and to avoid 'heavy' IRQs from loading certain CPUs
  unfairly over CPUs that handle 'light' IRQs. The IRQ system has no
  knowledge about how 'heavy' an IRQ handler is in terms of CPU cycles.

here is the design and implementation:

- we make per-irq decisions about where the IRQ will go to next. Right
  now it's a fastpath and a slowpath, the real stuff happens in the slow
  path. The fastpath is very lightweight.

- [ i decided not to measure IRQ handler overhead via RDTSC - it ends up
    being very messy, and if we want to be 100% fair then we also need to
    measure softirq overhead, and since there is no 1:1 relationship
    between softirq load and hardirq load, it's impossible to do
    correctly. So the IRQ balancer achieves fairness via randomness. ]

- we stay affine in the micro timescale, and we are loading the CPUs
  fairly in the macro timescale. The IO-APIC's lowest priority
  distribution method rotated IRQs between CPUs once per IRQ, which was
  the worst possible solution for good cache-affinity.

- to achieve fairness and to avoid lock-step situations some real
  randomness is needed. The IRQs will wander in the allowed CPU group
  randomly, in a brownean motion fashion. This is what the 'move()'
  function accomplishes. The IRQ moves one step forward or one step
  backwards in the allowed CPU mask. [ Note that this achieves a level of
  NUMA affinity as well, nearby CPUs are more likely to be NUMA-affine. ]

- the irq balancer has some knowledge about 'how idle' a single CPU is.
  The idle task updates the idle_timestamp. Since this update is in the
  idle-to-be codepath, it does not increase the latency of idle-wakeup,
  the overhead should be zero in all cases that matter. The idle-balancing
  happens the following way: when searching for the next target CPU after
  a 'IRQ tick' has expired, we first search 'idle enough' CPUs in the
  allowed set. If this does not succeed then we search all CPUs.

- the patch is fully compatible with the /proc/irq/*/smp_affinity
  interface as well, everything works as expected.

note that the current implementation can be expressed equivalently in
terms of timer-interrupt-driven IRQ redirection. But i wanted to get some
real feedback before removing the possibility to do finer grained
decisions - and the per-IRQ overhead is very small anyway.

into home.transmeta.com:/home/torvalds/v2.5/linux

fixes this problem.

into flint.arm.linux.org.uk:/usr/src/linux-bk-2.5/linux-2.5-rmk

into flint.arm.linux.org.uk:/usr/src/linux-bk-2.5/linux-2.5-rmk

This patch updates the defconfig for the Shark and adds an
extern and a define so that the kernel compiles for the Shark.

Regards
  Alexander

Make arch/arm/kernel/armksyms.c compile again with gcc 3.0.2 because of new EXPORT_SYMBOL_NOVERS(abort); in patch-2_4_18-rmk3.gz. See my mail "EXPORT_SYMBOL_NOVERS(abort) in armksyms.c?" in linux-arm-kernel list from Mon, 25 Mar 2002.

Dirk

into home.transmeta.com:/home/torvalds/v2.5/linux

(intel_thermal_interrupt() defined but not used)

For !CONFIG_SMP we want the empty inline setup_per_cpu_areas().
If CONFIG_SMP is set, we never want the empty inline. If we use the
generic implementation, we have it here, if not the arch has it somwhere
else (hopefully).

This makes the cpqfc driver recognize the HP Tachyon.  I moved the
device list to an __initdata structure so the driver doesn't build it at
runtime and changed it to use the proper PCI_DEVICE_ID_* names. 

With this patch applied, the driver happily detects the disks attached
to my HP Tachyon.

- Kill unneded parameters to ide_cmd_ioctl() and ide_task_ioctl().

- Apply Petr Vendrovecs fix for 32bit ver 16bit transfers.

- Make CD-ROM usable again by guarding the generic routines against request
   field abuse found there. We will try to convert this driver to the just to be
   finished struct ata_request after the generic changes stabilize a bit.
   The strcut ata_taskfile and struct ata_request merge to be more preciese.

- Don't provide symbolic links in /proc/ide - they are redundant data.

- Try to use a more reasonable default capacity value in ata_capacity().

- Fix ata_put() ata_get() usage in ide_check_media_change().

- Small readability fixes to the option parsing code.

- Apply Vojtech Pavliks /proc PIIX output fix.

- Replace all occurrences of ide_wait_taskfile() with ide_raw_taskfile().  One
   duplicated code path fewer.

Included is the latest version of the code. Indenting it properly
actually reduced the size of the files by another 10K or so.

Removes an atavism in declaration of sys_nfsservctl() - sorry, I should've
remove that junk when cond_syscall() thing was done.

Found by Andrew Morton <akpm@zip.com.au>

 This patch fixes small typo in ikernel informational message.

 This patch fixes a problem that was created during inode structure
 cleanup/ private parts separation. This fix was made by Chris Mason.
 This is very critical bugfix. Without it, filesystem corruption
 happens on savelinks processing and possibly in some other cases.

This patch removes one tail_conversion object out of build list,
because it was specified twice. (noticed by Jeff Garzik)

This patch removes confusing warning about journal replay on readonly FS

This patch is to change comment of CONFIG_REISERFS_PROC_INFO config item,
to make it more clear.

This patch renames reiserfs debugging option in config output,
to make its meaning more clear.

This patch is to fix journal replay bug where old code would replay
transactions with mount_id != mount_id recorded in journal header.
Fixed by Chris Mason.

This patch solves a problem where separate journal device was not freed
if journal initialisation failed

This patch is to add forgotten metadata journaling for a case when
we free blocks after tail conversion failures. Found and fixed by Chris Mason

This patch is to fix a case where flag was not set at inode-read time which
prevented 32bit uid/gid to work correctly.

This patch is to convert pap14030 panic into warning. While doing this,
a bug was uncovered, that when get_block() returns a failure, buffer
is still marked as mapped, and on subsequent access to this buffer
get_block() was not called anymore. This is also fixed.

This patch is to fix a lookup problem on bigendian platforms

This patch is to fix a problem when directory's atime was not updated on
readdir(). Patch is written by Chris Mason.