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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	Preeti U Murthy <preeti@linux.vnet.ibm.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Fengguang Wu <fengguang.wu@intel.com>,
	Frederic Weisbecker <frederic@kernel.org>,
	Pan Jacob jun <jacob.jun.pan@intel.com>, LKP <lkp@01.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Zhang Rui <rui.zhang@intel.com>
Subject: [PATCH 3.14 33/98] tick/powerclamp: Remove tick_nohz_idle abuse
Date: Sun, 25 Jan 2015 10:06:51 -0800	[thread overview]
Message-ID: <20150125180714.308459776@linuxfoundation.org> (raw)
In-Reply-To: <20150125180712.859646324@linuxfoundation.org>

3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thomas Gleixner <tglx@linutronix.de>

commit a5fd9733a30d18d7ac23f17080e7e07bb3205b69 upstream.

commit 4dbd27711cd9 "tick: export nohz tick idle symbols for module
use" was merged via the thermal tree without an explicit ack from the
relevant maintainers.

The exports are abused by the intel powerclamp driver which implements
a fake idle state from a sched FIFO task. This causes all kinds of
wreckage in the NOHZ core code which rightfully assumes that
tick_nohz_idle_enter/exit() are only called from the idle task itself.

Recent changes in the NOHZ core lead to a failure of the powerclamp
driver and now people try to hack completely broken and backwards
workarounds into the NOHZ core code. This is completely unacceptable
and just papers over the real problem. There are way more subtle
issues lurking around the corner.

The real solution is to fix the powerclamp driver by rewriting it with
a sane concept, but that's beyond the scope of this.

So the only solution for now is to remove the calls into the core NOHZ
code from the powerclamp trainwreck along with the exports.

Fixes: d6d71ee4a14a "PM: Introduce Intel PowerClamp Driver"
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Pan Jacob jun <jacob.jun.pan@intel.com>
Cc: LKP <lkp@01.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412181110110.17382@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/thermal/intel_powerclamp.c |    2 --
 kernel/time/tick-sched.c           |    2 --
 2 files changed, 4 deletions(-)

--- a/drivers/thermal/intel_powerclamp.c
+++ b/drivers/thermal/intel_powerclamp.c
@@ -435,7 +435,6 @@ static int clamp_thread(void *arg)
 		 * allowed. thus jiffies are updated properly.
 		 */
 		preempt_disable();
-		tick_nohz_idle_enter();
 		/* mwait until target jiffies is reached */
 		while (time_before(jiffies, target_jiffies)) {
 			unsigned long ecx = 1;
@@ -451,7 +450,6 @@ static int clamp_thread(void *arg)
 			start_critical_timings();
 			atomic_inc(&idle_wakeup_counter);
 		}
-		tick_nohz_idle_exit();
 		preempt_enable();
 	}
 	del_timer_sync(&wakeup_timer);
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -807,7 +807,6 @@ void tick_nohz_idle_enter(void)
 
 	local_irq_enable();
 }
-EXPORT_SYMBOL_GPL(tick_nohz_idle_enter);
 
 /**
  * tick_nohz_irq_exit - update next tick event from interrupt exit
@@ -934,7 +933,6 @@ void tick_nohz_idle_exit(void)
 
 	local_irq_enable();
 }
-EXPORT_SYMBOL_GPL(tick_nohz_idle_exit);
 
 static int tick_nohz_reprogram(struct tick_sched *ts, ktime_t now)
 {



  parent reply	other threads:[~2015-01-25 19:24 UTC|newest]

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-25 18:06 [PATCH 3.14 00/98] 3.14.30-stable review Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 02/98] netlink: Always copy on mmap TX Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 03/98] netlink: Dont reorder loads/stores before marking mmap netlink frame as available Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 04/98] in6: fix conflict with glibc Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 05/98] tg3: tg3_disable_ints using uninitialized mailbox value to disable interrupts Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 07/98] batman-adv: Unify fragment size calculation Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 08/98] batman-adv: avoid NULL dereferences and fix if check Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 09/98] net: Fix stacked vlan offload features computation Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 10/98] net: Reset secmark when scrubbing packet Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 11/98] tcp: Do not apply TSO segment limit to non-TSO packets Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 12/98] alx: fix alx_poll() Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 13/98] team: avoid possible underflow of count_pending value for notify_peers and mcast_rejoin Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 14/98] enic: fix rx skb checksum Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 15/98] net/core: Handle csum for CHECKSUM_COMPLETE VXLAN forwarding Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 16/98] drm/vmwgfx: Fix fence event code Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 17/98] drm/ttm: Avoid memory allocation from shrinker functions Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 18/98] drm/radeon: fix typo in CI dpm disable Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 19/98] drm/radeon: work around a hw bug in MGCG on CIK Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 21/98] drm/radeon: properly filter DP1.2 4k modes on non-DP1.2 hw Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 22/98] drm/i915: Dont complain about stolen conflicts on gen3 Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 23/98] drm/i915: Only warn the first time we attempt to mmio whilst suspended Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 24/98] drm/nv4c/mc: disable msi Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 27/98] ARC: [nsimosci] move peripherals to match model to FPGA Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 28/98] ARC: switch to generic ENTRY/END assembler annotations Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 29/98] cfg80211: dont WARN about two consecutive Country IE hint Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 30/98] cfg80211: avoid mem leak on driver hint set Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 31/98] cfg80211: Fix 160 MHz channels with 80+80 and 160 MHz drivers Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 32/98] hp_accel: Add support for HP ZBook 15 Greg Kroah-Hartman
2015-01-25 18:06 ` Greg Kroah-Hartman [this message]
2015-01-25 18:06 ` [PATCH 3.14 34/98] genirq: Prevent proc race against freeing of irq descriptors Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 35/98] iscsi-target: Fail connection on short sendmsg writes Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 36/98] Revert "[SCSI] mpt2sas: Remove phys on topology change." Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 37/98] Revert "[SCSI] mpt3sas: Remove phys on topology change" Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 38/98] scsi: blacklist RSOC for Microsoft iSCSI target devices Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 39/98] clk: samsung: Fix double add of syscore ops after driver rebind Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 40/98] clk: Really fix deadlock with mmap_sem Greg Kroah-Hartman
2015-01-26 12:46   ` Luis Henriques
2015-01-26 22:20     ` Greg Kroah-Hartman
2015-01-25 18:06 ` [PATCH 3.14 41/98] clk: Dont try to use a struct clk* after it could have been freed Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 42/98] parisc: fix out-of-register compiler error in ldcw inline assembler function Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 43/98] storvsc: ring buffer failures may result in I/O freeze Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 44/98] net: ethernet: cpsw: fix hangs with interrupts Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 45/98] video/logo: prevent use of logos after they have been freed Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 46/98] [media] smiapp-pll: Correct clock debug prints Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 48/98] [media] smiapp: Take mutex during PLL update in sensor initialisation Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 49/98] [media] sound: simplify au0828 quirk table Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 50/98] [media] sound: Update au0828 quirks table Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 51/98] [media] uvcvideo: Fix destruction order in uvc_delete() Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 52/98] vfio-pci: Fix the check on pci device type in vfio_pci_probe() Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 53/98] drivers: net: cpsw: fix multicast flush in dual emac mode Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 54/98] ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 55/98] NFSv4.1: Fix client id trunking on Linux Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 56/98] gpiolib: of: Correct error handling in of_get_named_gpiod_flags Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 57/98] gpio: fix memory and reference leaks in gpiochip_add error path Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 58/98] OHCI: add a quirk for ULi M5237 blocking on reset Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 59/98] usb: dwc3: gadget: Fix TRB preparation during SG Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 60/98] usb: dwc3: gadget: Stop TRB preparation after limit is reached Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 61/98] USB: cp210x: fix ID for production CEL MeshConnect USB Stick Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 62/98] USB: cp210x: add IDs for CEL USB sticks and MeshWorks devices Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 63/98] USB: keyspan: fix null-deref at probe Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 64/98] USB: console: fix uninitialised ldisc semaphore Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 65/98] USB: console: fix potential use after free Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 66/98] USB: EHCI: fix initialization bug in iso_stream_schedule() Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 67/98] usb: musb: stuff leak of struct usb_hcd Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 68/98] can: kvaser_usb: Dont free packets when tight on URBs Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 69/98] can: kvaser_usb: Reset all URB tx contexts upon channel close Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 70/98] can: kvaser_usb: Dont send a RESET_CHIP for non-existing channels Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 72/98] Input: I8042 - add Acer Aspire 7738 to the nomux list Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 73/98] ARM: dts: imx25: Fix the SPI1 clocks Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 74/98] ARM: imx6q: drop unnecessary semicolon Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 75/98] ARM: clk-imx6q: fix video divider for rev T0 1.0 Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 76/98] ARM: omap5/dra7xx: Fix frequency typos Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 77/98] ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 78/98] decompress_bunzip2: off by one in get_next_block() Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 79/98] um: Skip futex_atomic_cmpxchg_inatomic() test Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 80/98] x86, um: actually mark system call tables readonly Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 81/98] LOCKD: Fix a race when initialising nlmsvc_timeout Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 82/98] tcm_loop: Fixup tag handling Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 83/98] tcm_loop: Fix wrong I_T nexus association Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 84/98] vhost-scsi: Add missing virtio-scsi -> TCM attribute conversion Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 85/98] iscsi,iser-target: Initiate termination only once Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 86/98] iser-target: Fix flush + disconnect completion handling Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 87/98] iser-target: Parallelize CM connection establishment Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 88/98] iser-target: Fix connected_handler + teardown flow race Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 89/98] iser-target: Handle ADDR_CHANGE event for listener cm_id Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 90/98] iser-target: Fix implicit termination of connections Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 91/98] bcache: Make sure to pass GFP_WAIT to mempool_alloc() Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 92/98] KVM: nVMX: Disable unrestricted mode if ept=0 Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 93/98] netfilter: ipset: small potential read beyond the end of buffer Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 94/98] net: prevent of emerging cross-namespace symlinks Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 95/98] net: fix creation adjacent device symlinks Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 96/98] fsnotify: next_i is freed during fsnotify_unmount_inodes Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 97/98] s390/3215: fix hanging console issue Greg Kroah-Hartman
2015-01-25 18:07 ` [PATCH 3.14 98/98] s390/3215: fix tty output containing tabs Greg Kroah-Hartman
2015-01-25 21:37 ` [PATCH 3.14 00/98] 3.14.30-stable review Guenter Roeck
2015-01-26 17:43 ` Shuah Khan

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