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2010-12-17rcu: limit rcu_node leaf-level fanoutPaul E. McKenney
Some recent benchmarks have indicated possible lock contention on the leaf-level rcu_node locks. This commit therefore limits the number of CPUs per leaf-level rcu_node structure to 16, in other words, there can be at most 16 rcu_data structures fanning into a given rcu_node structure. Prior to this, the limit was 32 on 32-bit systems and 64 on 64-bit systems. Note that the fanout of non-leaf rcu_node structures is unchanged. The organization of accesses to the rcu_node tree is such that references to non-leaf rcu_node structures are much less frequent than to the leaf structures. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-12-17rcu: fine-tune grace-period begin/end checksPaul E. McKenney
Use the CPU's bit in rnp->qsmask to determine whether or not the CPU should try to report a quiescent state. Handle overflow in the check for rdp->gpnum having fallen behind. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-12-17rcu: Keep gpnum and completed fields synchronizedFrederic Weisbecker
When a CPU that was in an extended quiescent state wakes up and catches up with grace periods that remote CPUs completed on its behalf, we update the completed field but not the gpnum that keeps a stale value of a backward grace period ID. Later, note_new_gpnum() will interpret the shift between the local CPU and the node grace period ID as some new grace period to handle and will then start to hunt quiescent state. But if every grace periods have already been completed, this interpretation becomes broken. And we'll be stuck in clusters of spurious softirqs because rcu_report_qs_rdp() will make this broken state run into infinite loop. The solution, as suggested by Lai Jiangshan, is to ensure that the gpnum and completed fields are well synchronized when we catch up with completed grace periods on their behalf by other cpus. This way we won't start noting spurious new grace periods. Suggested-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <rostedt@goodmis.org Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-12-17rcu: Stop chasing QS if another CPU did it for usFrederic Weisbecker
When a CPU is idle and others CPUs handled its extended quiescent state to complete grace periods on its behalf, it will catch up with completed grace periods numbers when it wakes up. But at this point there might be no more grace period to complete, but still the woken CPU always keeps its stale qs_pending value and will then continue to chase quiescent states even if its not needed anymore. This results in clusters of spurious softirqs until a new real grace period is started. Because if we continue to chase quiescent states but we have completed every grace periods, rcu_report_qs_rdp() is puzzled and makes that state run into infinite loops. As suggested by Lai Jiangshan, just reset qs_pending if someone completed every grace periods on our behalf. Suggested-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-12-17rcu: increase synchronize_sched_expedited() batchingTejun Heo
The fix in commit #6a0cc49 requires more than three concurrent instances of synchronize_sched_expedited() before batching is possible. This patch uses a ticket-counter-like approach that is also not unrelated to Lai Jiangshan's Ring RCU to allow sharing of expedited grace periods even when there are only two concurrent instances of synchronize_sched_expedited(). This commit builds on Tejun's original posting, which may be found at http://lkml.org/lkml/2010/11/9/204, adding memory barriers, avoiding overflow of signed integers (other than via atomic_t), and fixing the detection of batching. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-12-17Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/bnx2x/bnx2x.h drivers/net/wireless/iwlwifi/iwl-1000.c drivers/net/wireless/iwlwifi/iwl-6000.c drivers/net/wireless/iwlwifi/iwl-core.h drivers/vhost/vhost.c
2010-12-17netlink: fix gcc -Wconversion compilation warningDmitry V. Levin
$ cat << EOF | gcc -Wconversion -xc -S -o/dev/null - unsigned f(void) {return NLMSG_HDRLEN;} EOF <stdin>: In function 'f': <stdin>:3:26: warning: negative integer implicitly converted to unsigned type Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-17asix: add USB ID for Logitec LAN-GTJ U2AArnaud Ebalard
Logitec LAN-GTJ U2A (http://www.pro.logitec.co.jp/pro/g/gLAN-GTJU2A/) USB 2.0 10/10/1000 Ethernet adapter is based on ASIX AX88178 chipset. This patch adds missing USB ID for the device. Signed-off-by: Arnaud Ebalard <arno@natisbad.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-17MIPS: Fix build errors in sc-mips.cKevin Cernekee
Seen with malta_defconfig on Linus' tree: CC arch/mips/mm/sc-mips.o arch/mips/mm/sc-mips.c: In function 'mips_sc_is_activated': arch/mips/mm/sc-mips.c:77: error: 'config2' undeclared (first use in this function) arch/mips/mm/sc-mips.c:77: error: (Each undeclared identifier is reported only once arch/mips/mm/sc-mips.c:77: error: for each function it appears in.) arch/mips/mm/sc-mips.c:81: error: 'tmp' undeclared (first use in this function) make[2]: *** [arch/mips/mm/sc-mips.o] Error 1 make[1]: *** [arch/mips/mm] Error 2 make: *** [arch/mips] Error 2 [Ralf: Cosmetic changes to minimize the number of arguments passed to mips_sc_is_activated] Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/1752/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-12-17qlcnic: reset pci function unconditionally during probeRajesh Borundia
Some boot code drivers dont have cleanup routine, so pci function remains in unknown state prior to driver load. So during driver load issue FLR unconditionally. Update driver version to 5.0.14. Signed-off-by: Rajesh Borundia <rajesh.borundia@qlogic.com> Signed-off-by: Amit Kumar Salecha <amit.salecha@qlogic.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-17qlcnic: fix ocm window register offset calculationRajesh Borundia
OCM window register offset was calculated incorrectly for pci function greater than zero. Signed-off-by: Rajesh Borundia <rajesh.borundia@qlogic.com> Signed-off-by: Amit Kumar Salecha <amit.salecha@qlogic.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-17qlcnic: fix LED test when interface is down.Sucheta Chakraborty
When interface is down, create temporary context to config LED. Signed-off-by: Sucheta Chakraborty <sucheta.chakraborty@qlogic.com> Signed-off-by: Amit Kumar Salecha <amit.salecha@qlogic.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-17tehuti: Firmware filename is tehuti/bdx.binBen Hutchings
My conversion of tehuti to use request_firmware() was confused about the filename of the firmware blob. Change the driver to match the blob. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-17x86: avoid high BIOS area when allocating address spaceBjorn Helgaas
This prevents allocation of the last 2MB before 4GB. The experiment described here shows Windows 7 ignoring the last 1MB: https://bugzilla.kernel.org/show_bug.cgi?id=23542#c27 This patch ignores the top 2MB instead of just 1MB because H. Peter Anvin says "There will be ROM at the top of the 32-bit address space; it's a fact of the architecture, and on at least older systems it was common to have a shadow 1 MiB below." Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-17x86: avoid E820 regions when allocating address spaceBjorn Helgaas
When we allocate address space, e.g., to assign it to a PCI device, don't allocate anything mentioned in the BIOS E820 memory map. On recent machines (2008 and newer), we assign PCI resources from the windows described by the ACPI PCI host bridge _CRS. On many Dell machines, these windows overlap some E820 reserved areas, e.g., BIOS-e820: 00000000bfe4dc00 - 00000000c0000000 (reserved) pci_root PNP0A03:00: host bridge window [mem 0xbff00000-0xdfffffff] If we put devices at 0xbff00000, they don't work, probably because that's really RAM, not I/O memory. This patch prevents that by removing the 0xbfe4dc00-0xbfffffff area from the "available" resource. I'm not very happy with this solution because Windows solves the problem differently (it seems to ignore E820 reserved areas and it allocates top-down instead of bottom-up; details at comment 45 of the bugzilla below). That means we're vulnerable to BIOS defects that Windows would not trip over. For example, if BIOS described a device in ACPI but didn't mention it in E820, Windows would work fine but Linux would fail. Reference: https://bugzilla.kernel.org/show_bug.cgi?id=16228 Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-17x86: avoid low BIOS area when allocating address spaceBjorn Helgaas
This implements arch_remove_reservations() so allocate_resource() can avoid any arch-specific reserved areas. This currently just avoids the BIOS area (the first 1MB), but could be used for E820 reserved areas if that turns out to be necessary. We previously avoided this area in pcibios_align_resource(). This patch moves the test from that PCI-specific path to a generic path, so *all* resource allocations will avoid this area. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-17resources: add arch hook for preventing allocation in reserved areasBjorn Helgaas
This adds arch_remove_reservations(), which an arch can implement if it needs to protect part of the address space from allocation. Sometimes that can be done by just putting a region in the resource tree, but there are cases where that doesn't work well. For example, x86 BIOS E820 reservations are not related to devices, so they may overlap part of, all of, or more than a device resource, so they may not end up at the correct spot in the resource tree. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-17Revert "resources: support allocating space within a region from the top down"Bjorn Helgaas
This reverts commit e7f8567db9a7f6b3151b0b275e245c1cef0d9c70. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-17Revert "PCI: allocate bus resources from the top down"Bjorn Helgaas
This reverts commit b126b4703afa4010b161784a43650337676dd03b. We're going back to the old behavior of allocating from bus resources in _CRS order. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-17Revert "x86/PCI: allocate space from the end of a region, not the beginning"Bjorn Helgaas
This reverts commit dc9887dc02e37bcf83f4e792aa14b07782ef54cf. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-17Revert "x86: allocate space within a region top-down"Bjorn Helgaas
This reverts commit 1af3c2e45e7a641e774bbb84fa428f2f0bf2d9c9. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-17Revert "PCI: fix pci_bus_alloc_resource() hang, prefer positive decode"Bjorn Helgaas
This reverts commit 82e3e767c21fef2b1b38868e20eb4e470a1e38e3. We're going back to considering bus resources in the order we found them (in _CRS order, when we're using _CRS), so we don't need to define any ordering. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-12-17ceph: handle partial result from get_user_pagesHenry C Chang
The get_user_pages() helper can return fewer than the requested pages. Error out in that case, and clean up the partial result. Signed-off-by: Henry C Chang <henry_c_chang@tcloudcomputing.com> Signed-off-by: Sage Weil <sage@newdream.net>
2010-12-17ceph: mark user pages dirty on direct-io readsHenry C Chang
For read operation, we have to set the argument _write_ of get_user_pages to 1 since we will write data to pages. Also, we need to SetPageDirty before releasing these pages. Signed-off-by: Henry C Chang <henry_c_chang@tcloudcomputing.com> Signed-off-by: Sage Weil <sage@newdream.net>
2010-12-17ceph: fix null pointer dereference in ceph_init_dentry for nfs reexportSage Weil
The fh_to_dentry etc. methods use ceph_init_dentry(), which assumes that d_parent is defined. It isn't for those callers, so check! Signed-off-by: Sage Weil <sage@newdream.net>
2010-12-17Merge branch 'for_linus' of git://github.com/at91linux/linux-2.6-at91Linus Torvalds
* 'for_linus' of git://github.com/at91linux/linux-2.6-at91: at91: Refactor Stamp9G20 and PControl G20 board file at91: Fix uhpck clock rate in upll case
2010-12-17Merge branch 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: Fix preemption counter leak in kvm_timer_init() KVM: enlarge number of possible CPUID leaves KVM: SVM: Do not report xsave in supported cpuid KVM: Fix OSXSAVE after migration
2010-12-17Merge branch 'pm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 * 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: PM / Runtime: Fix pm_runtime_suspended() PM / Hibernate: Restore old swap signature to avoid user space breakage PM / Hibernate: Fix PM_POST_* notification with user-space suspend
2010-12-17Merge branch 'bkl_removal' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 * 'bkl_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: [media] uvcvideo: Convert to unlocked_ioctl [media] uvcvideo: Lock stream mutex when accessing format-related information [media] uvcvideo: Move mmap() handler to uvc_queue.c [media] uvcvideo: Move mutex lock/unlock inside uvc_free_buffers [media] uvcvideo: Lock controls mutex when querying menus [media] v4l2-dev: fix race condition [media] V4L: improve the BKL replacement heuristic [media] v4l2-dev: use mutex_lock_interruptible instead of plain mutex_lock [media] cx18: convert to unlocked_ioctl [media] radio-timb: convert to unlocked_ioctl [media] sh_vou: convert to unlocked_ioctl [media] cafe_ccic: replace ioctl by unlocked_ioctl [media] et61x251_core: trivial conversion to unlocked_ioctl [media] sn9c102: convert to unlocked_ioctl [media] BKL: trivial ioctl -> unlocked_ioctl video driver conversions [media] typhoon: convert to unlocked_ioctl [media] si4713: convert to unlocked_ioctl [media] tea5764: convert to unlocked_ioctl [media] cadet: use unlocked_ioctl [media] BKL: trivial BKL removal from V4L2 radio drivers
2010-12-17Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: ALSA: hda - Fix conflict of Mic Boot controls ALSA: HDA: Enable subwoofer on Asus G73Jw ALSA: HDA: Fix auto-mute on Lenovo Edge 14 ASoC: Fix bias power down of non-DAPM codec ASoC: WM8580: Fix R8 initial value ASoC: fix deemphasis control in wm8904/55/60 codecs
2010-12-17percpu,x86: relocate this_cpu_add_return() and friendsTejun Heo
- include/linux/percpu.h: this_cpu_add_return() and friends were located next to __this_cpu_add_return(). However, the overall organization is to first group by preemption safeness. Relocate this_cpu_add_return() and friends to preemption-safe area. - arch/x86/include/asm/percpu.h: Relocate percpu_add_return_op() after other more basic operations. Relocate [__]this_cpu_add_return_8() so that they're first grouped by preemption safeness. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux.com>
2010-12-17Merge branch 'fix/asoc' into for-linusTakashi Iwai
2010-12-17Merge branch 'fix/hda' into for-linusTakashi Iwai
2010-12-17ALSA: hda - Fix conflict of Mic Boot controlsTakashi Iwai
Due to the recent change for multiple mics assignment, we need to handle the index of each Mic Boost control respectively. Otherwise the driver gets the control element conflicts, and gives the unsable state. Reference: kernel bug 25002 https://bugzilla.kernel.org/show_bug.cgi?id=25002 Reported-and-tested-by: Adam Williamson <awilliam@redhat.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-12-17connector: Use this_cpu operationsChristoph Lameter
The patch was originally in the use cpuops patchset but it needs an inc_return and is therefore dependent on an extension of the cpu ops. Fixed up and verified that it compiles. get_seq can benefit from this_cpu_operations. Address calculation is avoided and the increment is done using an xadd. Cc: Scott James Remnant <scott@ubuntu.com> Cc: Mike Frysinger <vapier@gentoo.org> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17xen: Use this_cpu_inc_returnChristoph Lameter
__this_cpu_inc_return reduces code and simplifies code. Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com>
2010-12-17taskstats: Use this_cpu_opsChristoph Lameter
Use this_cpu_inc_return in one place and avoid ugly __raw_get_cpu in another. V3->V4: - Fix off by one. V4-V4f: - Use &listener_array Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17random: Use this_cpu_inc_returnChristoph Lameter
__this_cpu_inc can create a single instruction to do the same as __get_cpu_var()++. Cc: Richard Kennedy <richard@rsk.demon.co.uk> Cc: Matt Mackall <mpm@selenic.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17fs: Use this_cpu_inc_return in buffer.cChristoph Lameter
__this_cpu_inc can create a single instruction with the same effect as the _get_cpu_var(..)++ construct in buffer.c. Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Christoph Hellwig <hch@lst.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17highmem: Use this_cpu_xx_return() operationsChristoph Lameter
Use this_cpu operations to optimize access primitives for highmem. The main effect is the avoidance of address calculations through the use of a segment prefix. V3->V4 - kmap_atomic_idx: Do not return a value. - Use __this_cpu_dec without HIGHMEM_DEBUG Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17vmstat: Use this_cpu_inc_return for vm statisticsChristoph Lameter
this_cpu_inc_return() saves us a memory access there. Code size does not change. V1->V2: - Fixed the location of the __per_cpu pointer attributes - Sparse checked V2->V3: - Move fixes to __percpu attribute usage to earlier patch Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17Merge branch 'this_cpu_ops' into for-2.6.38Tejun Heo
2010-12-17x86: Support for this_cpu_add, sub, dec, inc_returnChristoph Lameter
Supply an implementation for x86 in order to generate more efficient code. V2->V3: - Cleanup - Remove strange type checking from percpu_add_return_op. tj: - Dropped unused typedef from percpu_add_return_op(). - Renamed ret__ to paro_ret__ in percpu_add_return_op(). - Minor indentation adjustments. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17percpu: Generic support for this_cpu_add, sub, dec, inc_returnChristoph Lameter
Introduce generic support for this_cpu_add_return etc. The fallback is to realize these operations with simpler __this_cpu_ops. tj: - Reformatted __cpu_size_call_return2() to make it more consistent with its neighbors. - Dropped unnecessary temp variable ret__ from __this_cpu_generic_add_return(). Reviewed-by: Tejun Heo <tj@kernel.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17core: Replace __get_cpu_var with __this_cpu_read if not used for an address.Christoph Lameter
__get_cpu_var() can be replaced with this_cpu_read and will then use a single read instruction with implied address calculation to access the correct per cpu instance. However, the address of a per cpu variable passed to __this_cpu_read() cannot be determined (since it's an implied address conversion through segment prefixes). Therefore apply this only to uses of __get_cpu_var where the address of the variable is not used. Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Hugh Dickins <hughd@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17xen: Use this_cpu_opsChristoph Lameter
Use this_cpu_ops to reduce code size and simplify things in various places. V3->V4: Move instance of this_cpu_inc_return to a later patchset so that this patch can be applied without infrastructure changes. Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17fs: Use this_cpu_xx operations in buffer.cChristoph Lameter
Optimize various per cpu area operations through these new percpu operations. These operations avoid address calculations through the use of segment prefixes and multiple memory references through RMW instructions etc. Reduces code size: Before: christoph@linux-2.6$ size fs/buffer.o text data bss dec hex filename 19169 80 28 19277 4b4d fs/buffer.o After: christoph@linux-2.6$ size fs/buffer.o text data bss dec hex filename 19138 80 28 19246 4b2e fs/buffer.o V3->V4: - Move the use of this_cpu_inc_return into a later patch so that this one can go in without percpu infrastructure changes. Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Christoph Hellwig <hch@lst.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17fakekey: Simplify speakup_fake_key_pressed through this_cpu_opsChristoph Lameter
The whole function can be expressed as a simple this_cpu_read() operation. The function overhead is now likely multiple times that of the single instruction that is executed in it. Sedat: fixed compile failure caused by an extra ')'. Cc: William Hubbs <w.d.hubbs@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17kprobes: Use this_cpu_opsChristoph Lameter
Use this_cpu ops in various places to optimize per cpu data access. Cc: Jason Baron <jbaron@redhat.com> Cc: Namhyung Kim <namhyung@gmail.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-12-17drivers: Replace __get_cpu_var with __this_cpu_read if not used for an address.Christoph Lameter
__get_cpu_var() can be replaced with this_cpu_read and will then use a single read instruction with implied address calculation to access the correct per cpu instance. However, the address of a per cpu variable passed to __this_cpu_read() cannot be determed (since its an implied address conversion through segment prefixes). Therefore apply this only to uses of __get_cpu_var where the addres of the variable is not used. V3->V4: - Move one instance of this_cpu_inc_return to a later patch so that this one can go in without percpu infrastructrure changes. Sedat: fixed compile failure caused by an extra ')'. Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>