nohz: Reduce overhead under high-freq idling patterns

One testbox of mine (Intel Nehalem, 16-way) uses MWAIT for its idle routine,
which apparently can break out of its idle loop rather frequently, with
high frequency.

In that case NO_HZ_FULL=y kernels show high ksoftirqd overhead and constant
context switching, because tick_nohz_stop_sched_tick() will, if
delta_jiffies == 0, mis-identify this as a timer event - activating the
TIMER_SOFTIRQ, which wakes up ksoftirqd.

Fix this by treating delta_jiffies == 0 the same way we treat other short
wakeups, delta_jiffies == 1.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: flar2 <asegaert@gmail.com>
mmc: core: Refactor bus speed selection code

The bus speed selection code in mmc_card_init() is convoluted, refactor
the code to simplify this and make it simpler for adding new bus speed
capabilities.

Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
mmc: card: update long_sequential_write_test queue depth

Since some systems have higher memory pressure, we limit the amount of
simultaneous test requests. The former limitation was 118, due to the
request queue size, but now we further restrict this number to half.

Change-Id: I893b9ad1b133c922f90497b0ec1f416514529fb8
CRs-fixed: 510814
Signed-off-by: Lee Susman <lsusman@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
sdhci: sdhci_stop_request() returns error when no request

There is race between sdhci_tasklet_finish()
and sdhci_stop_request(): when the request is finished before
stop flow called, error returned.

Change-Id: Ic036feae925b2e9e5435e44f97b24a179547bf49
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
mmc: core: skip stop flow when current request already done

When mmc_stop_request() has no request to stop, because underlying
host driver reported this, the flow should wait for the mmc done()
callback marking that urgent still pending.

Change-Id: Iacc95591ee76a965916af05a31a67dd8997c233e
CRs-Fixed: 538117
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
mmc: block: Fix error path of mmc_blk_alloc_req()

In case of any error within mmc_blk_alloc_req(), the bitmaps
that keep track of devices are not getting cleared. This may
result in failure to detect a card in case it reaches maximum
devices limitation. Fix it by clearing those bitmaps appropriately.

CRs-fixed: 563264
Change-Id: I0e23c45856355565534146f5fabb957fd4b1d007
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
mmc: sdhci: Use max timeout and skip timeout calculation

Several data-timeout issues were seen, most of which were
due to the card taking a longer time to respond. This patch
increases the timeout of the controller to 0xF i.e. max
possible.

Change-Id: I6739de3eb5d9cccf8e39d9dc4730056782334162
CRs-Fixed: 536832
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>