Commit Graph

24990 Commits

Author SHA1 Message Date
Stefan Richter 6585fa8aa5 Doc/kernel-parameters.txt: slightly reword sentence about restrictions
The previous patch somewhat diverted the train of thought.
Here I am trying to bring the valued reader back on track.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:44:30 +02:00
Stefan Richter a901ebb907 Doc/kernel-parameters.txt: mention modinfo and sysfs
Doc/kernel-parameters.txt: mention modinfo and sysfs

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:43:18 +02:00
Stefan Richter 0ee9d71f02 Doc/kernel-parameters.txt: delete false version information and history
Doc/kernel-parameters.txt: delete false version information and history

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:42:29 +02:00
Kalin KOZHUHAROV 8ba8e95ed1 Fix comments: s/granuality/granularity/
I was grepping through the code and some `grep ganularity -R .` didn't
catch what I thought. Then looking closer I saw the term "granuality"
used in only four places (in comments) and granularity in many more
places describing the same idea. Some other facts:

dictionary.com does not know such a word
define:granuality on google is not found (and pages for granuality are
mostly related to patches to the kernel)
it has not been discussed as a term on LKML, AFAICS (=Can Search)

To be consistent, I think granularity should be used everywhere.

Signed-off-by: Kalin KOZHUHAROV <kalin@thinrope.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:41:22 +02:00
Horms 36a891b67f kexec: grammar fix for crash_save_this_cpu()
kexec: grammar fix for crash_save_this_cpu()

Signed-Off-By: Horms <horms@verge.net.au>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:39:17 +02:00
Horms 08039264d5 Documentation: Make fujitsu/frv/kernel-ABI.txt 80 columns wide
Documentation: Make kernel-ABI.txt 80 columns wide

Note that this only has line-wrapping and white-space changes.
No text was changed at all.

Signed-Off-By: Horms <horms@verge.net.au>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:38:15 +02:00
Horms abe37e5a13 Documentation: Reorder documentation of nomca and nomce
My patch to add brief documentation of the nomca boot parameter
added it out of alphabetical order.

Signed-Off-By: Horms <horms@verge.net.au>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:36:09 +02:00
Uwe Zeisberger 2e150f6e1a fix typo "Suposse" -> "Suppose"
Signed-off-by: Uwe Zeisberger <zeisberg@informatik.uni-freiburg.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:29:43 +02:00
Eric Sesterhenn 3a8dc8930e BUG_ON() Conversion in drivers/s390/char/tape_block.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:28:11 +02:00
Eric Sesterhenn e048a8a688 BUG_ON() Conversion in drivers/s390/block/dasd_erp.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:27:08 +02:00
Eric Sesterhenn 5aae277ed6 BUG_ON() Conversion in mm/vmalloc.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:26:09 +02:00
Eric Sesterhenn e74ca2b49b BUG_ON() Conversion in mm/swap_state.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:25:12 +02:00
Eric Sesterhenn 46a350ef98 BUG_ON() Conversion in mm/mmap.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:23:29 +02:00
Eric Sesterhenn 8abd8e298e BUG_ON() Conversion in kernel/printk.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:21:17 +02:00
Eric Sesterhenn 9bc98fc6fd BUG_ON() Conversion in ipc/util.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:20:23 +02:00
Eric Sesterhenn 99cee0cd75 BUG_ON() Conversion in fs/sysfs/
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:18:38 +02:00
Eric Sesterhenn 5df0d31241 BUG_ON() Conversion in fs/smbfs/
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:16:26 +02:00
Eric Sesterhenn 4b4d1cc733 BUG_ON() Conversion in fs/jffs2/
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:15:35 +02:00
Eric Sesterhenn 0bf3ba538a BUG_ON() Conversion in fs/hfsplus/
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:14:43 +02:00
Eric Sesterhenn 7dddb12c63 BUG_ON() Conversion in fs/exec.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:13:38 +02:00
Eric Sesterhenn d4569d2e69 BUG_ON() Conversion in fs/direct-io.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:10:13 +02:00
Eric Sesterhenn 9e77c485f7 BUG_ON() Conversion in md/raid1.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:08:49 +02:00
Eric Sesterhenn 543cb2a451 BUG_ON() Conversion in md/dm-target.c
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:08:12 +02:00
Adrian Bunk 58ef2c4ce3 typos: s/ducument/document/
s/ducument/document/

Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:04:59 +02:00
Adrian Bunk 2a08b4e904 fix the email address of Wendy Xiong
Replace a bouncing version of the email address of Wendy Xiong with a
working one.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:04:20 +02:00
Adrian Bunk 5637a2ee5d fix a typo in the AIC7XXX_DEBUG_MASK help text
This patch fixes a typo in the AIC7XXX_DEBUG_MASK help text.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:03:38 +02:00
Adrian Bunk 3e6e952d1d help text: SOFTWARE_SUSPEND doesn't need ACPI
The note that SOFTWARE_SUSPEND doesn't need APM is helpful, but nowadays
the information that it doesn't need ACPI, too, is even more helpful.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:03:08 +02:00
Anders Larsen 3a3f8a126d MTD: remove obsolete Kconfig options
Remove the obsolete Kconfig options MTD_CFI_AMDSTD_RETRY
and MTD_CFI_AMDSTD_RETRY_MAX

The code that depended on these was removed in early 2004, but
Kconfig was not updated accordingly.

Signed-off-by: Anders Larsen <al@alarsen.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01 01:02:42 +02:00
Linus Torvalds 4b75679f60 Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
  [NET]: Allow skb headroom to be overridden
  [TCP]: Kill unused extern decl for tcp_v4_hash_connecting()
  [NET]: add SO_RCVBUF comment
  [NET]: Deinline some larger functions from netdevice.h
  [DCCP]: Use NULL for pointers, comfort sparse.
  [DECNET]: Fix refcount
2006-03-31 12:52:30 -08:00
Jes Sorensen 30c14e40ed [PATCH] avoid unaligned access when accessing poll stack
Commit 70674f95c0a2ea694d5c39f4e514f538a09be36f:

  [PATCH] Optimize select/poll by putting small data sets on the stack

resulted in the poll stack being 4-byte aligned on 64-bit architectures,
causing misaligned accesses to elements in the array.

This patch fixes it by declaring the stack in terms of 'long' instead
of 'char'.

Force alignment of poll and select stacks to long to avoid unaligned
access on 64 bit architectures.

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:30:48 -08:00
Linus Torvalds d21c356b08 Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  [PATCH] libata: fix ata_xfer_tbl termination
  [PATCH] libata: make ata_qc_issue complete failed qcs
  [PATCH] libata: fix ata_qc_issue failure path
  [PATCH] ata_piix: fix ich6/m_map_db
  [libata] ahci: add ATI SB600 PCI IDs
2006-03-31 12:28:01 -08:00
David Howells 108b42b4b9 [PATCH] Document Linux's memory barriers [try #7]
The attached patch documents the Linux kernel's memory barriers.

I've updated it from the comments I've been given.

The per-arch notes sections are gone because it's clear that there are so many
exceptions, that it's not worth having them.

I've added a list of references to other documents.

I've tried to get rid of the concept of memory accesses appearing on the bus;
what matters is apparent behaviour with respect to other observers in the
system.

Interrupts barrier effects are now considered to be non-existent. They may be
there, but you may not rely on them.

I've added a couple of definition sections at the top of the document: one to
specify the minimum execution model that may be assumed, the other to specify
what this document refers to by the term "memory".

I've made greater mention of the use of mmiowb().

I've adjusted the way in which caches are described, and described the fun
that can be had with cache coherence maintenance being unordered and data
dependency not being necessarily implicit.

I've described (smp_)read_barrier_depends().

I've rearranged the order of the sections, so that memory barriers are
discussed in abstract first, and then described the memory barrier facilities
available on Linux, before going on to more real-world discussions and examples.

I've added information about the lack of memory barriering effects with atomic
ops and bitops.

I've added information about control dependencies.

I've added more diagrams to illustrate caching interactions between CPUs.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:27:01 -08:00
Kirill Korotaev 4286229868 [PATCH] wrong error path in dup_fd() leading to oopses in RCU
Wrong error path in dup_fd() - it should return NULL on error,
not an address of already freed memory :/

Triggered by OpenVZ stress test suite.

What is interesting is that it was causing different oopses in RCU like
below:
Call Trace:
   [<c013492c>] rcu_do_batch+0x2c/0x80
   [<c0134bdd>] rcu_process_callbacks+0x3d/0x70
   [<c0126cf3>] tasklet_action+0x73/0xe0
   [<c01269aa>] __do_softirq+0x10a/0x130
   [<c01058ff>] do_softirq+0x4f/0x60
   =======================
   [<c0113817>] smp_apic_timer_interrupt+0x77/0x110
   [<c0103b54>] apic_timer_interrupt+0x1c/0x24
  Code:  Bad EIP value.
   <0>Kernel panic - not syncing: Fatal exception in interrupt

Signed-Off-By: Pavel Emelianov <xemul@sw.ru>
Signed-Off-By: Dmitry Mishin <dim@openvz.org>
Signed-Off-By: Kirill Korotaev <dev@openvz.org>
Signed-Off-By: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:25:46 -08:00
Nicolas Pitre e358c1a2c4 [PATCH] mutex: some cleanups
Turn some macros into inline functions and add proper type checking as
well as being more readable.  Also a minor comment adjustment.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:01 -08:00
Jesper Juhl a58e00e7da [PATCH] Decrease number of pointer derefs in jsm_tty.c
Decrease the number of pointer derefs in drivers/serial/jsm/jsm_tty.c

Benefits of the patch:
 - Fewer pointer dereferences should make the code slightly faster.
 - Size of generated code is smaller
 - Improved readability

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: "V. ANANDA KRISHNAN" <mansarov@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:01 -08:00
Adrian Bunk a244e1698a [PATCH] fs/namei.c: make lookup_hash() static
As announced, lookup_hash() can now become static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:01 -08:00
Adrian Bunk 0cb3463f04 [PATCH] unexport get_wchan
The only user of get_wchan is the proc fs - and proc can't be built modular.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:01 -08:00
NeilBrown ec350a7fc1 [PATCH] md: Raid-6 did not create sysfs entries for stripe cache
Signed-off-by: Brad Campbell <brad@wasp.net.au>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:01 -08:00
NeilBrown 926ce2d8a7 [PATCH] md: Remove some code that can sleep from under a spinlock
And remove the comments that were put in inplace of a fix too....

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:01 -08:00
NeilBrown 6b1117d505 [PATCH] md: Don't clear bits in bitmap when writing to one device fails during recovery
Currently a device failure during recovery leaves bits set in the bitmap.
This normally isn't a problem as the offending device will be rejected because
of errors.  However if device re-adding is being used with non-persistent
bitmaps, this can be a problem.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:01 -08:00
Michael Hanselmann 39451a73a2 [PATCH] fbdev: Remove old radeon driver
This patch removes the old radeon driver which has been replaced by a
newer one.

Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:01 -08:00
Antonino A. Daplas a536093a2f [PATCH] fbcon: Fix big-endian bogosity in slow_imageblit()
The monochrome->color expansion routine that handles bitmaps which have
(widths % 8) != 0 (slow_imageblit) produces corrupt characters in big-endian.
This is caused by a bogus bit test in slow_imageblit().

Fix.

This patch may deserve to go to the stable tree.  The code has already been
well tested in little-endian machines.  It's only in big-endian where there is
uncertainty and Herbert confirmed that this is the correct way to go.

It should not introduce regressions.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Acked-by: Herbert Poetzl <herbert@13thfloor.at>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:00 -08:00
Richard Purdie 2cbbb3b59c [PATCH] pxafb: Minor driver fixes
Fixes for the pxafb driver:

* Return -EINVAL for resolutions that are too large as per framebuffer
  driver policy.

* Increase the error timeout for disabling the LCD controller.  The current
  timeout is sometimes too short on the Sharp Zaurus Cxx00 hardware and an
  extra delay in an error path shouldn't pose any problems.

* Fix a dev reference which causes a compile error when DEBUG is defined.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:00 -08:00
Richard Purdie 2c0f5fb08e [PATCH] backlight: corgi_bl: Generalise to support other Sharp SL hardware
Generalise the Corgi backlight driver by moving the default intensity and
limit mask settings into the platform specific data structure.  This enables
the driver to support other Zaurus hardware, specifically the SL-6000x (Tosa)
model.

Also change the spinlock to a mutex (the spinlock is overkill).

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:00 -08:00
Richard Purdie 5f27a27bd7 [PATCH] backlight: HP Jornada 680 Backlight driver updates/fixes
Updates to the HP Jornada 680 Backlight driver:

- Correct the suspend/resume functions so the driver compiles
  (SUSPEND_POWER_DOWN/RESUME_POWER_ON no longer exist).

- Convert the driver to match the recent platform device changes.

- Replace the unsafe static struct platform_device with dynamic allocation.

- Convert the driver to the new backlight code.

This has not been tested on a device due to lack of hardware but wouldn't
compile beforehand.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:00 -08:00
Richard Purdie 6ca017658b [PATCH] backlight: Backlight Class Improvements
Backlight class attributes are currently easy to implement incorrectly.
Moving certain handling into the backlight core prevents this whilst at the
same time makes the drivers simpler and consistent.  The following changes are
included:

The brightness attribute only sets and reads the brightness variable in the
backlight_properties structure.

The power attribute only sets and reads the power variable in the
backlight_properties structure.

Any framebuffer blanking events change a variable fb_blank in the
backlight_properties structure.

The backlight driver has only two functions to implement.  One function is
called when any of the above properties change (to update the backlight
brightness), the second is called to return the current backlight brightness
value.  A new attribute "actual_brightness" is added to return this brightness
as determined by the driver having combined all the above factors (and any
driver/device specific factors).

Additionally, the backlight core takes care of checking the maximum brightness
is not exceeded and of turning off the backlight before device removal.

The corgi backlight driver is updated to reflect these changes.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:00 -08:00
Alberto Mardegan 9b0e1c5dd2 [PATCH] w100fb: Add acceleration support to ATI Imageon
Add acceleration support in w100fb.c (i.e.  ATI Imageons) for the copyarea and
fillrect operations.

Signed-off-by: Alberto Mardegan <mardy@users.sourceforge.net>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:00 -08:00
Antonino A. Daplas 1a37d5f510 [PATCH] fbcon: Save current display during initialization
The current display was not saved during initialization.  This leads to hard
to track console corruption, such as a misplaced cursor, which is correctible
by switching consoles.  Fix this minor bug.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:00 -08:00
Eric W. Biederman 3e7e241f8c [PATCH] dcache: Add helper d_hash_and_lookup
It is very common to hash a dentry and then to call lookup.  If we take fs
specific hash functions into account the full hash logic can get ugly.
Further full_name_hash as an inline function is almost 100 bytes on x86 so
having a non-inline choice in some cases can measurably decrease code size.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:00 -08:00
Eric W. Biederman 92476d7fc0 [PATCH] pidhash: Refactor the pid hash table
Simplifies the code, reduces the need for 4 pid hash tables, and makes the
code more capable.

In the discussions I had with Oleg it was felt that to a large extent the
cleanup itself justified the work.  With struct pid being dynamically
allocated meant we could create the hash table entry when the pid was
allocated and free the hash table entry when the pid was freed.  Instead of
playing with the hash lists when ever a process would attach or detach to a
process.

For myself the fact that it gave what my previous task_ref patch gave for free
with simpler code was a big win.  The problem is that if you hold a reference
to struct task_struct you lock in 10K of low memory.  If you do that in a user
controllable way like /proc does, with an unprivileged but hostile user space
application with typical resource limits of 1000 fds and 100 processes I can
trigger the OOM killer by consuming all of low memory with task structs, on a
machine wight 1GB of low memory.

If I instead hold a reference to struct pid which holds a pointer to my
task_struct, I don't suffer from that problem because struct pid is 2 orders
of magnitude smaller.  In fact struct pid is small enough that most other
kernel data structures dwarf it, so simply limiting the number of referring
data structures is enough to prevent exhaustion of low memory.

This splits the current struct pid into two structures, struct pid and struct
pid_link, and reduces our number of hash tables from PIDTYPE_MAX to just one.
struct pid_link is the per process linkage into the hash tables and lives in
struct task_struct.  struct pid is given an indepedent lifetime, and holds
pointers to each of the pid types.

The independent life of struct pid simplifies attach_pid, and detach_pid,
because we are always manipulating the list of pids and not the hash table.
In addition in giving struct pid an indpendent life it makes the concept much
more powerful.

Kernel data structures can now embed a struct pid * instead of a pid_t and
not suffer from pid wrap around problems or from keeping unnecessarily
large amounts of memory allocated.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:00 -08:00