Scale writeback cache per backing device, proportional to its writeout speed.

By decoupling the BDI dirty thresholds a number of problems we currently have
will go away, namely:

 - mutual interference starvation (for any number of BDIs);
 - deadlocks with stacked BDIs (loop, FUSE and local NFS mounts).

It might be that all dirty pages are for a single BDI while other BDIs are
idling. By giving each BDI a 'fair' share of the dirty limit, each one can have
dirty pages outstanding and make progress.

A global threshold also creates a deadlock for stacked BDIs; when A writes to
B, and A generates enough dirty pages to get throttled, B will never start
writeback until the dirty pages go away. Again, by giving each BDI its own
'independent' dirty limit, this problem is avoided.

So the problem is to determine how to distribute the total dirty limit across
the BDIs fairly and efficiently. A DBI that has a large dirty limit but does
not have any dirty pages outstanding is a waste.

What is done is to keep a floating proportion between the DBIs based on
writeback completions. This way faster/more active devices get a larger share
than slower/idle devices.

[akpm@linux-foundation.org: fix warnings]
[hugh@veritas.com: Fix occasional hang when a task couldn't get out of balance_dirty_pages]
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Given a set of objects, floating proportions aims to efficiently give the
proportional 'activity' of a single item as compared to the whole set. Where
'activity' is a measure of a temporal property of the items.

It is efficient in that it need not inspect any other items of the set
in order to provide the answer. It is not even needed to know how many
other items there are.

It has one parameter, and that is the period of 'time' over which the
'activity' is measured.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Count per BDI writeback pages.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Count per BDI reclaimable pages; nr_reclaimable = nr_dirty + nr_unstable.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide scalable per backing_dev_info statistics counters.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

provide BDI constructor/destructor hooks

[akpm@linux-foundation.org: compile fix]
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

provide a way to tell lockdep about percpu_counters that are supposed to be
used from irq safe contexts.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

alloc_percpu can fail, propagate that error.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide an accurate version of percpu_counter_read.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

 s/percpu_counter_sum/&_positive/

Because its consitent with percpu_counter_read*
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide a method to set a percpu counter to a specified value.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

percpu_counter is a s64 counter, make _add consitent.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Because the current batch setup has an quadric error bound on the counter,
allow for an alternative setup.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Hugh spotted that some code does:
  percpu_counter_add(&counter, -unsignedlong)

which, when the amount argument is of type s32, sort-of works thanks to
two's-complement. However when we'd change the type to s64 this breaks on 32bit
machines, because the promotion rules zero extend the unsigned number.

Provide percpu_counter_sub() to hide the s64 cast. That is:
  percpu_counter_sub(&counter, foo)
is equal to:
  percpu_counter_add(&counter, -(s64)foo);
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

 s/percpu_counter_mod/percpu_counter_add/

Because its a better name, _mod implies modulo.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These patches aim to improve balance_dirty_pages() and directly address three
issues:
  1) inter device starvation
  2) stacked device deadlocks
  3) inter process starvation

1 and 2 are a direct result from removing the global dirty limit and using
per device dirty limits. By giving each device its own dirty limit is will
no longer starve another device, and the cyclic dependancy on the dirty limit
is broken.

In order to efficiently distribute the dirty limit across the independant
devices a floating proportion is used, this will allocate a share of the total
limit proportional to the device's recent activity.

3 is done by also scaling the dirty limit proportional to the current task's
recent dirty rate.

This patch:

nfs: remove congestion_end().  It's redundant, clear_bdi_congested() already
wakes the waiters.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update dump_task_altivec() (which has so far never been put to use) so that
it dumps the Altivec/VMX registers (VR[0] - VR[31], VSCR and VRSAVE) in the
same format as the ptrace get_vrregs(), and add the appropriate glue
typedef and #defines to make it work.

A new note type of NT_PPC_VMX was chosen to be 0x100 (arbitrarily) because
it allows the low range values to be used for more generic purposes and
0x100 seems an adequate starting point for PowerPC extensions.
Signed-off-by: NMark Nelson <markn@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace NT_PRXFPREG with ELF_CORE_XFPREG_TYPE in the coredump code which
allows for more flexibility in the note type for the state of 'extended
floating point' implementations in coredumps.  New note types can now be
added with an appropriate #define.

This does #define ELF_CORE_XFPREG_TYPE to be NT_PRXFPREG in all
current users so there's are no change in behaviour.

This will let us use different note types on powerpc for the Altivec/VMX
state that some PowerPC cpus have (G4, PPC970, POWER6) and for the SPE
(signal processing extension) state that some embedded PowerPC cpus from
Freescale have.
Signed-off-by: NMark Nelson <markn@au1.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Try to fix the mess created by sysfs braindamage.

 - refactor code internal to fs/namei.c a little to avoid too much
   duplication:
	o __lookup_hash_kern is renamed back to __lookup_hash
	o the old __lookup_hash goes away, permission checks moves to
	  the two callers
	o useless inline qualifiers on above functions go away
 - lookup_one_len_kern loses it's last argument and is renamed to
   lookup_one_noperm to make it's useage a little more clear
 - added kerneldoc comments to describe lookup_one_len aswell as
   lookup_one_noperm and make it very clear that no one should use
   the latter ever.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6:
  WOL bugfix for 3c59x.c
  skge 1.12
  skge: add a debug interface
  skge: eeprom support
  skge: internal stats
  skge: XM PHY handling fixes
  skge: changing MTU while running causes problems
  skge: fix ram buffer size calculation
  gianfar: Fix compile regression caused by 09f75cd7
  net: Fix new EMAC driver for NAPI changes
  bonding: two small fixes for IPoIB support
  e1000e: don't poke PHY registers to retreive link status
  e1000e: fix error checks
  e1000e: Fix debug printk macro
  tokenring/3c359.c: fixed array index problem
  [netdrvr] forcedeth: remove in-driver copy of net_device_stats
  [netdrvr] forcedeth: improved probe info; dev_printk() cleanups
  forcedeth: fix NAPI rx poll function

AFAICS, fallout from repacing include of blkdev.h with include of bio.h.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes a lost 'key' variable declaration that went missing in a
mismerge (commit b981d8b3)
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some NICs (3c905B) can not generate PME in power state PCI_D0, while others
like 3c905C can.  Call pci_enable_wake() with PCI_D3hot should give proper
WOL for 3c905B.
Signed-off-by: NSteffen Klassert <klassert@mathematik.tu-chemnitz.de>
Tested-by: NHarry Coin <hcoin@n4comm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

version update
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Add a debugfs interface to look at internal ring state.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Add ability to read/write EEPROM
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Use internal stats structure
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Change how PHY is managed on SysKonnect fibre based boards.
Poll for PHY coming up 1 per second, but use interrupt to detect loss.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Rather than bring network down/up when changing MTU,
only need to impact receiver.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This fixes problems with transmit hangs on older fiber based SysKonnect boards.

Adjust ram buffer sizing calculation to make it correct on all boards
and make it like the code in sky2 driver.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Signed-off-by: NLi Yang <leoli@freescale.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

net: Fix new EMAC driver for NAPI changes

This fixes the new EMAC driver for the NAPI updates. The previous patch
by Roland Dreier (already applied) to do that doesn't actually work. This
applies on top of it makes it work on my test Ebony machine.

This patch depends on "net: Add __napi_sycnhronize() to sync with napi poll"
posted previously.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

	Two small fixes to IPoIB support for bonding:

	1- copy header_ops from slave to bonding for IPoIB slaves
	2- move release and destroy logic to UNREGISTER from GOING_DOWN
	   notifier to avoid double release

	Set bonding to version 3.2.1.

Signed-off-by: Moni Shoua <monis at voltaire.com>
Signed-off-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Apparently poking the link status registers when autonegotiation
is running on the PHY might botch the PHY link on 80003es2lan
devices. While this is a very rare condition we can completely
avoid it alltogether by just using the MAC link bits to provide
the proper information to ethtool.
Signed-off-by: NAuke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Spotted by the Coverity checker.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAuke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Spotted by Joe Perches.
Signed-off-by: NAuke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

The xl_laa array is just 6 bytes long, so we should substract
10 from the index, like is also done some lines above already.
Signed-Off-By: NMarcus Meissner <meissner@suse.de>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

A copy of struct net_device_stats now lives in struct net_device,
making in-driver copies a waste of memory.
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

main change:
* greatly improve per-NIC probe diagnostic output.  Similar to other
  net drivers, print out MAC address, PHY info, and various hardware and
  software flags that may be relevant.

other changes:
* similar to other net drivers, only print the initial version message
  when we have found at least one board.

* don't bother to print error message when pci_enable_device() fails,
  it will do so for us.

* use dev_printk() rather than printk() in nv_probe().  This gives
  use a standardized output similar to the rest of the kernel, and
  eliminates the need to manually print out PCI bus id.

* use DRV_NAME constant where appropriate

* clean struct pci_driver indentation
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

fix the forcedeth NAPI poll function to not emit this warning:

[  186.635916] WARNING: at net/core/dev.c:2166 net_rx_action()
[  186.641351]  [<c060d9f5>] net_rx_action+0x145/0x1b0
[  186.646191]  [<c011d752>] __do_softirq+0x42/0x90
[  186.650784]  [<c011d7c6>] do_softirq+0x26/0x30
[  186.655202]  [<c011db48>] local_bh_enable+0x48/0xa0
[  186.660055]  [<c06023e0>] lock_sock_nested+0xa0/0xc0
[  186.664995]  [<c065da16>] tcp_recvmsg+0x16/0xbc0
[  186.669588]  [<c013e94b>] __generic_file_aio_write_nolock+0x27b/0x520
[  186.676001]  [<c0601d75>] sock_common_recvmsg+0x45/0x70
[  186.681202]  [<c05ff5df>] sock_aio_read+0x11f/0x140
[  186.686054]  [<c015c086>] do_sync_read+0xc6/0x110
[  186.690735]  [<c012b9b0>] autoremove_wake_function+0x0/0x40
[  186.696280]  [<c060dcfc>] net_tx_action+0x3c/0xe0
[  186.700961]  [<c015c9c2>] vfs_read+0x132/0x140
[  186.705378]  [<c015cd41>] sys_read+0x41/0x70
[  186.709625]  [<c0102b66>] sysenter_past_esp+0x5f/0x89
[  186.714651]  =======================
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>