mm: implement WasActive page flag (for improving cleancache)[faux123] (Feedback welcome if there is a different/better way to do this without using a page flag!)

Since about 2.6.27, the page replacement algorithm maintains
an "active" bit to help decide which pages are most eligible
to reclaim, see http://linux-mm.org/PageReplacementDesign

This "active' information is also useful to cleancache but is lost
by the time that cleancache has the opportunity to preserve the
pageful of data.  This patch adds a new page flag "WasActive" to
retain the state.  The flag may possibly be useful elsewhere.

It is up to each cleancache backend to utilize the bit as
it desires.  The matching patch for zcache is included here
for clarification/discussion purposes, though it will need to
go through GregKH and the staging tree.

The patch resolves issues reported with cleancache which occur
especially during streaming workloads on older processors,
see https://lkml.org/lkml/2011/8/17/351

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
backported to 2.6.35 by faux123

Signed-off-by: garwedgess <garethwilliams21@gmail.com>
nohz: Remove ts->inidle checks before restarting the tick

ts->inidle is set by tick_nohz_stop_sched_tick(1) and unset
by tick_nohz_restart_sched_tick(). These two calls are assumed
to be always paired. This means that by the time we call
tick_nohz_restart_sched_tick(), ts->inidle is supposed to
be always set to 1.

Remove the checks for ts->inidle in tick_nohz_restart_sched_tick().
This simplifies a bit the code and improves its debuggability
(ie: ensure the call is paired with a tick_nohz_stop_sched_tick() call).

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
pkt_sched: ingress socket filter by mark

Allow bpf to set a filter to drop packets that dont
match a specific mark

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
filter: Add SKF_AD_QUEUE instruction

It can help being able to filter packets on their queue_mapping.

If filter performance is not good, we could add a "numqueue" field
in struct packet_type, so that netif_nit_deliver() and other functions
can directly ignore packets with not expected queue number.

Lets experiment this simple filter extension first.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
net: Socket filter ancilliary data access for skb->dev->type

Add an SKF_AD_HATYPE field to the packet ancilliary data area, giving
access to skb->dev->type, as reported in the sll_hatype field.

When capturing packets on a PF_PACKET/SOCK_RAW socket bound to all
interfaces, there doesn't appear to be a way for the filter program to
actually find out the underlying hardware type the packet was captured
on. This patch adds such ability.

This patch also handles the case where skb->dev can be NULL, such as on
netlink sockets.

Signed-off-by: Paul Evans <leonerd@leonerd.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
ARM: improve compiler's ability to optimize page tables

Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
cfs: tweaks for responsiveness

Signed-off-by: garwedgess <garethwilliams21@gmail.com>
mm: clear pages_scanned only if draining pcp adds pages to the buddy allocator

Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
net: JIT compiler for BPF filters
mm: vmscan: factor out page reference checks

Signed-off-by: garwedgess <garethwilliams21@gmail.com>
mm: define PAGE_MAPPING_FLAGS

Signed-off-by: garwedgess <garethwilliams21@gmail.com>
mm: vmscan: do not writeback filesystem pages in direct reclaim

Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
writeback: remove unused nonblocking and congestion checks

Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
writeback: laptop-mode: Make flushes per-device

Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
writeback: fix mixed up arguments to bdi_start_writeback()
Optimized RCU Tiny

Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
msm_battery: update the status upon resume

When the battery driver comes out of suspend, the charging status
might have changed on the remote side. Resync the local status with
remote upon resume.

CRs-Fixed: 277999

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
(cherry picked from commit 5f05de5d5ef73c9715a8942696a00c0e5290810d)

Change-Id: I4ca964a70be53209c70e40d41fb3078d81e04db0
Signed-off-by: Ramakrishna Prasad N <crpn@codeaurora.org>
Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
kernel.h: Add BUILD_BUG() macro.

We can place this in definitions that we expect the compiler to remove
by dead code elimination.  If this assertion fails, we get a nice
error message at build time.

The GCC function attribute error("message") was added in version 4.3,
so we define a new macro __linktime_error(message) to expand to this
for GCC-4.3 and later.  This will give us an error diagnostic from the
compiler on the line that fails.  For other compilers
__linktime_error(message) expands to nothing, and we have to be
content with a link time error, but at least we will still get a build
error.

BUILD_BUG() expands to the undefined function __build_bug_failed() and
will fail at link time if the compiler ever emits code for it.  On
GCC-4.3 and later, attribute((error())) is used so that the failure
will be noted at compile time instead.

Signed-off-by: David Daney <david.daney@cavium.com>
Backported to 2.6.35 from 3.2-rc3+

Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
hugetlb: Replace BUG() with BUILD_BUG() for dummy definitions.

The file linux/hugetlb.h has many places where dummy symbols were
defined so that the main source code would contain fewer:

    #ifdef CONFIG_HUGETLBFS

or

    #ifdef CONFIG_TRANSPARENT_HUGEPAGE

If there were any misuse of these symbols, the only symptom would be
an OOPS at runtime.  Change the BUG() to BUILD_BUG() to catch
any such abuse at compile time instead.

Signed-off-by: David Daney <david.daney@cavium.com>
backported to 2.6.35 from linux 3.2-rc3+

Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>
ARM: Add optimised swahb32() byteswap helper for v6 and above

ARMv6 and later processors have the REV16 instruction, which swaps
the bytes within each halfword of a register value.

This is already used to implement swab16(), but since the native
operation performaed by REV16 is actually swahb32(), this patch
renames the existing swab16() helper accordingly and defines
__arch_swab16() in terms of it.  This allows calls to both swab16()
and swahb32() to be optimised.

The compiler's generated code might improve someday, but as of
4.5.2 the code generated for pure C implementing these 16-bit
bytesswaps remains pessimal.

swahb32() is useful for converting 32-bit Thumb instructions
between integer and memory representation on BE8 platforms (among
other uses).

Signed-off-by: Dave Martin <dave.martin@xxxxxxxxxx>
Signed-off-by: nobodyAtall <tsogkas@ceid.upatras.gr>
Signed-off-by: garwedgess <garethwilliams21@gmail.com>