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2010-10-12pci: Cleanup the irq_desc mess in msiThomas Gleixner
Handing down irq_desc to msi just so that msi can access irq_desc.irq_data.msi_desc is a pretty stupid idea. The calling code can hand down a pointer to msi_desc so msi code does not need to know about the irq descriptor at all. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-10-12pci: Convert msi to new irq_chip functionsThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Tony Luck <tony.luck@intel.com> Cc: Russell King <linux@arm.linux.org.uk>
2010-10-12Merge branch 'x86/urgent' of into irq/sparseirqThomas Gleixner
Reason: Pull in the latest io_apic bugfixes Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-10-12genirq: Query arch for number of early descriptorsThomas Gleixner
sparse irq sets up NR_IRQS_LEGACY irq descriptors and archs then go ahead and allocate more. Use the unused return value of arch_probe_nr_irqs() to let the architecture return the number of early allocations. Fix up all users. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Implement irq reservationThomas Gleixner
Mark a range of interrupts as allocated. In the SPARSE_IRQ=n case we need this to update the bitmap for the legacy irqs so the enumerator via irq_get_next_irq() works. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-10-12genirq: Implement sane enumerationThomas Gleixner
Use the allocator bitmap to lookup active interrupts. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Implement a sane sparse_irq allocatorThomas Gleixner
The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Provide default irq init flagsThomas Gleixner
Arch code sets it's own irq_desc.status flags right after boot and for dynamically allocated interrupts. That might involve iterating over a huge array. Allow ARCH_IRQ_INIT_FLAGS to set separate flags aside of IRQ_DISABLED which is the default. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Remove early_init_irq_lock_class()Thomas Gleixner
early_init_irq_lock_class() is called way before anything touches the irq descriptors. In case of SPARSE_IRQ=y this is a NOP operation because the radix tree is empty at this point. For the SPARSE_IRQ=n case it's sufficient to set the lock class in early_init_irq(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Sanitize irq_data accessorsThomas Gleixner
Get the data structure from the core and provide inline wrappers to access the irq_data members. Provide accessor inlines for irq_data as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Provide status modifierThomas Gleixner
Provide a irq_desc.status modifier function to cleanup the direct access to irq_desc in arch and driver code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Remove unsused inlineThomas Gleixner
move_irq() has no users. Remove it and simplify the ifdef forrest while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Distangle irq.hThomas Gleixner
Move irq_desc and internal functions out of irq.h Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide config option to disable deprecated codeThomas Gleixner
This option covers now the old chip functions and the irq_desc data fields which are moving to struct irq_data. More stuff will follow. Pretty handy for testing a conversion, whether something broke or not. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide advanced irq chip functionsThomas Gleixner
The low level irq chip functions want access to irq_desc->irq_data. Provide new functions which hand down irq_data instead of the irq number so these functions avoid to call irq_to_desc() which is a radix tree lookup in case of sparse irq. This provides all the old functions except one: end(). end() is a relict of __do_IRQ() and will just go away with the __do_IRQ() code. The replacement for set_affinity() has an extra argument "bool force". The reason for this is to notify the low level code, that the move has to be done right away and cannot be delayed until the next interrupt happens. That's necessary to handle the irq fixup on cpu unplug in the generic code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121841.742126604@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Convert core code to irq_dataThomas Gleixner
Convert all references in the core code to orq, chip, handler_data, chip_data, msi_desc, affinity to irq_data.* Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Create irq_dataThomas Gleixner
Low level chip functions need access to irq_desc->handler_data, irq_desc->chip_data and irq_desc->msi_desc. We hand down the irq number to the low level functions, so they need to lookup irq_desc. With sparse irq this means a radix tree lookup. We could hand down irq_desc itself, but low level chip functions have no need to fiddle with it directly and we want to restrict access to irq_desc further. Preparatory patch for new chip functions. Note, that the ugly anon union/struct is there to avoid a full tree wide clean up for now. This is not going to last 3 years like __do_IRQ() Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121841.645542300@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (47 commits) tcp: Fix >4GB writes on 64-bit. net/9p: Mount only matching virtio channels de2104x: fix ethtool tproxy: check for transparent flag in ip_route_newports ipv6: add IPv6 to neighbour table overflow warning tcp: fix TSO FACK loss marking in tcp_mark_head_lost 3c59x: fix regression from patch "Add ethtool WOL support" ipv6: add a missing unregister_pernet_subsys call s390: use free_netdev(netdev) instead of kfree() sgiseeq: use free_netdev(netdev) instead of kfree() rionet: use free_netdev(netdev) instead of kfree() ibm_newemac: use free_netdev(netdev) instead of kfree() smsc911x: Add MODULE_ALIAS() net: reset skb queue mapping when rx'ing over tunnel br2684: fix scheduling while atomic de2104x: fix TP link detection de2104x: fix power management de2104x: disable autonegotiation on broken hardware net: fix a lockdep splat e1000e: 82579 do not gate auto config of PHY by hardware during nominal use ...
2010-09-27tcp: Fix >4GB writes on 64-bit.David S. Miller
Fixes kernel bugzilla #16603 tcp_sendmsg() truncates iov_len to an 'int' which a 4GB write to write zero bytes, for example. There is also the problem higher up of how verify_iovec() works. It wants to prevent the total length from looking like an error return value. However it does this using 'int', but syscalls return 'long' (and thus signed 64-bit on 64-bit machines). So it could trigger false-positives on 64-bit as written. So fix it to use 'long'. Reported-by: Olaf Bonorden <bono@onlinehome.de> Reported-by: Daniel Büse <dbuese@gmx.de> Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-27Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86/amd-iommu: Fix rounding-bug in __unmap_single x86/amd-iommu: Work around S3 BIOS bug x86/amd-iommu: Set iommu configuration flags in enable-loop x86, setup: Fix earlyprintk=serial,0x3f8,115200 x86, setup: Fix earlyprintk=serial,ttyS0,115200
2010-09-24Merge branch 'amd-iommu/2.6.36' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent
2010-09-23genirq: Cleanup irq_chip->typename leftoversThomas Gleixner
3 years transition phase is enough. Cleanup the last users and remove the cruft. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Leo Chen <leochen@broadcom.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Chris Zankel <chris@zankel.net>
2010-09-23x86/amd-iommu: Work around S3 BIOS bugJoerg Roedel
This patch adds a workaround for an IOMMU BIOS problem to the AMD IOMMU driver. The result of the bug is that the IOMMU does not execute commands anymore when the system comes out of the S3 state resulting in system failure. The bug in the BIOS is that is does not restore certain hardware specific registers correctly. This workaround reads out the contents of these registers at boot time and restores them on resume from S3. The workaround is limited to the specific IOMMU chipset where this problem occurs. Cc: stable@kernel.org Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2010-09-22arm: fix "arm: fix pci_set_consistent_dma_mask for dmabounce devices"FUJITA Tomonori
This fixes the regression caused by the commit 6fee48cd330c68 ("dma-mapping: arm: use generic pci_set_dma_mask and pci_set_consistent_dma_mask"). ARM needs to clip the dma coherent mask for dmabounce devices. This restores the old trick. Note that strictly speaking, the DMA API doesn't allow architectures to do such but I'm not sure it's worth adding the new API to set the dma mask that allows architectures to clip it. Reported-by: Krzysztof Halasa <khc@pm.waw.pl> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-22net: Move "struct net" declaration inside the __KERNEL__ macro guardOllie Wild
This patch reduces namespace pollution by moving the "struct net" declaration out of the userspace-facing portion of linux/netlink.h. It has no impact on the kernel. (This came up because we have several C++ applications which use "net" as a namespace name.) Signed-off-by: Ollie Wild <aaw@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-21fs: {lock,unlock}_flocks() stubs to prepare for BKL removalSage Weil
The lock structs are currently protected by the BKL, but are accessed by code in fs/locks.c and misc file system and DLM code. These stubs will allow all users to switch to the new interface before the implementation is changed to a spinlock. Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (21 commits) dca: disable dca on IOAT ver.3.0 multiple-IOH platforms netpoll: Disable IRQ around RCU dereference in netpoll_rx sctp: Do not reset the packet during sctp_packet_config(). net/llc: storing negative error codes in unsigned short MAINTAINERS: move atlx discussions to netdev drivers/net/cxgb3/cxgb3_main.c: prevent reading uninitialized stack memory drivers/net/eql.c: prevent reading uninitialized stack memory drivers/net/usb/hso.c: prevent reading uninitialized memory xfrm: dont assume rcu_read_lock in xfrm_output_one() r8169: Handle rxfifo errors on 8168 chips 3c59x: Remove atomic context inside vortex_{set|get}_wol tcp: Prevent overzealous packetization by SWS logic. net: RPS needs to depend upon USE_GENERIC_SMP_HELPERS phylib: fix PAL state machine restart on resume net: use rcu_barrier() in rollback_registered_many bonding: correctly process non-linear skbs ipv4: enable getsockopt() for IP_NODEFRAG ipv4: force_igmp_version ignored when a IGMPv3 query received ppp: potential NULL dereference in ppp_mp_explode() net/llc: make opt unsigned in llc_ui_setsockopt() ...
2010-09-17netpoll: Disable IRQ around RCU dereference in netpoll_rxHerbert Xu
We cannot use rcu_dereference_bh safely in netpoll_rx as we may be called with IRQs disabled. We could however simply disable IRQs as that too causes BH to be disabled and is safe in either case. Thanks to John Linville for discovering this bug and providing a patch. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-16Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: add documentation
2010-09-14Merge ssh://master.kernel.org/home/hpa/tree/secLinus Torvalds
* ssh://master.kernel.org/home/hpa/tree/sec: x86-64, compat: Retruncate rax after ia32 syscall entry tracing x86-64, compat: Test %rax for the syscall number, not %eax compat: Make compat_alloc_user_space() incorporate the access_ok()
2010-09-14Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6Linus Torvalds
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: SUNRPC: Fix the NFSv4 and RPCSEC_GSS Kconfig dependencies statfs() gives ESTALE error NFS: Fix a typo in nfs_sockaddr_match_ipaddr6 sunrpc: increase MAX_HASHTABLE_BITS to 14 gss:spkm3 miss returning error to caller when import security context gss:krb5 miss returning error to caller when import security context Remove incorrect do_vfs_lock message SUNRPC: cleanup state-machine ordering SUNRPC: Fix a race in rpc_info_open SUNRPC: Fix race corrupting rpc upcall Fix null dereference in call_allocate
2010-09-14compat: Make compat_alloc_user_space() incorporate the access_ok()H. Peter Anvin
compat_alloc_user_space() expects the caller to independently call access_ok() to verify the returned area. A missing call could introduce problems on some architectures. This patch incorporates the access_ok() check into compat_alloc_user_space() and also adds a sanity check on the length. The existing compat_alloc_user_space() implementations are renamed arch_compat_alloc_user_space() and are used as part of the implementation of the new global function. This patch assumes NULL will cause __get_user()/__put_user() to either fail or access userspace on all architectures. This should be followed by checking the return value of compat_access_user_space() for NULL in the callers, at which time the access_ok() in the callers can also be removed. Reported-by: Ben Hawkes <hawkes@sota.gen.nz> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: James Bottomley <jejb@parisc-linux.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: <stable@kernel.org>
2010-09-13Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: dquot: do full inode dirty in allocating space
2010-09-13Merge branch 'next-spi' of git://git.secretlab.ca/git/linux-2.6Linus Torvalds
* 'next-spi' of git://git.secretlab.ca/git/linux-2.6: spi/pl022: move probe call to subsys_initcall() powerpc/5200: mpc52xx_uart.c: Add of_node_put to avoid memory leak spi/pl022: fix APB pclk power regression on U300 spi/spi_s3c64xx: Warn if PIO transfers time out spi/s3c64xx: Fix incorrect reuse of 'val' local variable. spi/s3c64xx: Fix compilation warning spi/dw_spi: clean the cs_control code spi/dw_spi: Allow interrupt sharing spi/spi_s3c64xx: Increase dead reckoning time in wait_for_xfer() spi/spi_s3c64xx: Move to subsys_initcall() spi: free children in spi_unregister_master, not siblings gpiolib: Add 'struct gpio_chip' forward declaration for !GPIOLIB case of: Fix missing includes - ll_temac spi/spi_s3c64xx: Staticise non-exported functions spi/spi_s3c64xx: Make probe more robust against missing board config
2010-09-13workqueue: add documentationTejun Heo
Update copyright notice and add Documentation/workqueue.txt. Randy Dunlap, Dave Chinner: misc fixes. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-By: Florian Mickler <florian@mickler.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Dave Chinner <david@fromorbit.com>
2010-09-12SUNRPC: Fix a race in rpc_info_openTrond Myklebust
There is a race between rpc_info_open and rpc_release_client() in that nothing stops a process from opening the file after the clnt->cl_kref goes to zero. Fix this by using atomic_inc_unless_zero()... Reported-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org
2010-09-10Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: Range check cpu in blk_cpu_to_group scatterlist: prevent invalid free when alloc fails writeback: Fix lost wake-up shutting down writeback thread writeback: do not lose wakeup events when forking bdi threads cciss: fix reporting of max queue depth since init block: switch s390 tape_block and mg_disk to elevator_change() block: add function call to switch the IO scheduler from a driver fs/bio-integrity.c: return -ENOMEM on kmalloc failure bio-integrity.c: remove dependency on __GFP_NOFAIL BLOCK: fix bio.bi_rw handling block: put dev->kobj in blk_register_queue fail path cciss: handle allocation failure cfq-iosched: Documentation help for new tunables cfq-iosched: blktrace print per slice sector stats cfq-iosched: Implement tunable group_idle cfq-iosched: Do group share accounting in IOPS when slice_idle=0 cfq-iosched: Do not idle if slice_idle=0 cciss: disable doorbell reset on reset_devices blkio: Fix return code for mkdir calls
2010-09-09Merge branch 'vhost-net' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
2010-09-09Merge branch 'upstream-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev * 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev: libata-sff: Reenable Port Multiplier after libata-sff remodeling. libata: skip EH autopsy and recovery during suspend ahci: AHCI and RAID mode SATA patch for Intel Patsburg DeviceIDs ata_piix: IDE Mode SATA patch for Intel Patsburg DeviceIDs libata,pata_via: revert ata_wait_idle() removal from ata_sff/via_tf_load() ahci: fix hang on failed softreset pata_artop: Fix device ID parity check
2010-09-09libata-sff: Reenable Port Multiplier after libata-sff remodeling.Gwendal Grignou
Keep track of the link on the which the current request is in progress. It allows support of links behind port multiplier. Not all libata-sff is PMP compliant. Code for native BMDMA controller does not take in accound PMP. Tested on Marvell 7042 and Sil7526. Signed-off-by: Gwendal Grignou <gwendal@google.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2010-09-09libata: skip EH autopsy and recovery during suspendTejun Heo
For some mysterious reason, certain hardware reacts badly to usual EH actions while the system is going for suspend. As the devices won't be needed until the system is resumed, ask EH to skip usual autopsy and recovery and proceed directly to suspend. Signed-off-by: Tejun Heo <tj@kernel.org> Tested-by: Stephan Diestelhorst <stephan.diestelhorst@amd.com> Cc: stable@kernel.org Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2010-09-09mm: page allocator: calculate a better estimate of NR_FREE_PAGES when memory ↵Christoph Lameter
is low and kswapd is awake Ordinarily watermark checks are based on the vmstat NR_FREE_PAGES as it is cheaper than scanning a number of lists. To avoid synchronization overhead, counter deltas are maintained on a per-cpu basis and drained both periodically and when the delta is above a threshold. On large CPU systems, the difference between the estimated and real value of NR_FREE_PAGES can be very high. If NR_FREE_PAGES is much higher than number of real free page in buddy, the VM can allocate pages below min watermark, at worst reducing the real number of pages to zero. Even if the OOM killer kills some victim for freeing memory, it may not free memory if the exit path requires a new page resulting in livelock. This patch introduces a zone_page_state_snapshot() function (courtesy of Christoph) that takes a slightly more accurate view of an arbitrary vmstat counter. It is used to read NR_FREE_PAGES while kswapd is awake to avoid the watermark being accidentally broken. The estimate is not perfect and may result in cache line bounces but is expected to be lighter than the IPI calls necessary to continually drain the per-cpu counters while kswapd is awake. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09swap: discard while swapping only if SWAP_FLAG_DISCARDHugh Dickins
Tests with recent firmware on Intel X25-M 80GB and OCZ Vertex 60GB SSDs show a shift since I last tested in December: in part because of firmware updates, in part because of the necessary move from barriers to awaiting completion at the block layer. While discard at swapon still shows as slightly beneficial on both, discarding 1MB swap cluster when allocating is now disadvanteous: adds 25% overhead on Intel, adds 230% on OCZ (YMMV). Surrender: discard as presently implemented is more hindrance than help for swap; but might prove useful on other devices, or with improvements. So continue to do the discard at swapon, but make discard while swapping conditional on a SWAP_FLAG_DISCARD to sys_swapon() (which has been using only the lower 16 bits of int flags). We can add a --discard or -d to swapon(8), and a "discard" to swap in /etc/fstab: matching the mount option for btrfs, ext4, fat, gfs2, nilfs2. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Nigel Cunningham <nigel@tuxonice.net> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <jaxboe@fusionio.com> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09swap: revert special hibernation allocationHugh Dickins
Please revert 2.6.36-rc commit d2997b1042ec150616c1963b5e5e919ffd0b0ebf "hibernation: freeze swap at hibernation". It complicated matters by adding a second swap allocation path, just for hibernation; without in any way fixing the issue that it was intended to address - page reclaim after fixing the hibernation image might free swap from a page already imaged as swapcache, letting its swap be reallocated to store a different page of the image: resulting in data corruption if the imaged page were freed as clean then swapped back in. Pages freed to si->swap_map were still in danger of being reallocated by the alternative allocation path. I guess it inadvertently fixed slow SSD swap allocation for hibernation, as reported by Nigel Cunningham: by missing out the discards that occur on the usual swap allocation path; but that was unintentional, and needs a separate fix. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Ondrej Zary <linux@rainbow-software.org> Cc: Andrea Gelmini <andrea.gelmini@gmail.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Nigel Cunningham <nigel@tuxonice.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09gpio: sx150x: correct and refine reset-on-probe behaviorGregory Bean
Replace the arbitrary software-reset call from the device-probe method, because: - It is defective. To work correctly, it should be two byte writes, not a single word write. As it stands, it does nothing. - Some devices with sx150x expanders installed have their NRESET pins ganged on the same line, so resetting one causes the others to reset - not a nice thing to do arbitrarily! - The probe, usually taking place at boot, implies a recent hard-reset, so a software reset at this point is just a waste of energy anyway. Therefore, make it optional, defaulting to off, as this will match the common case of probing at powerup and also matches the current broken no-op behavior. Signed-off-by: Gregory Bean <gbean@codeaurora.org> Reviewed-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09mm: fix swapin race conditionAndrea Arcangeli
The pte_same check is reliable only if the swap entry remains pinned (by the page lock on swapcache). We've also to ensure the swapcache isn't removed before we take the lock as try_to_free_swap won't care about the page pin. One of the possible impacts of this patch is that a KSM-shared page can point to the anon_vma of another process, which could exit before the page is freed. This can leave a page with a pointer to a recycled anon_vma object, or worse, a pointer to something that is no longer an anon_vma. [riel@redhat.com: changelog help] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09cgroups: fix API thinkoMichael S. Tsirkin
Add cgroup_attach_task_all() The existing cgroup_attach_task_current_cg() API is called by a thread to attach another thread to all of its cgroups; this is unsuitable for cases where a privileged task wants to attach itself to the cgroups of a less privileged one, since the call must be made from the context of the target task. This patch adds a more generic cgroup_attach_task_all() API that allows both the source task and to-be-moved task to be specified. cgroup_attach_task_current_cg() becomes a specialization of the more generic new function. [menage@google.com: rewrote changelog] [akpm@linux-foundation.org: address reviewer comments] Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Ben Blum <bblum@google.com> Cc: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09kfifo: add parenthesis for macro parameter referenceHuang Ying
Some macro parameter references inside typeof() operator are not enclosed with parenthesis. It should be safer to add them. Signed-off-by: Huang Ying <ying.huang@intel.com> Acked-by: Stefani Seibold <stefani@seibold.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09mmc: avoid getting CID on SDIO-only cardsDavid Vrabel
The introduction of support for SD combo cards breaks the initialization of all CSR SDIO chips. The GO_IDLE (CMD0) in mmc_sd_get_cid() causes CSR chips to be reset (this is non-standard behavior). When initializing an SDIO card check for a combo card by using the memory present bit in the R4 response to IO_SEND_OP_COND (CMD5). This avoids the call to mmc_sd_get_cid() on an SDIO-only card. Signed-off-by: David Vrabel <david.vrabel@csr.com> Acked-by: Michal Mirolaw <mirq-linux@rere.qmqm.pl> Cc: <linux-mmc@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09lglock: make lg_lock_global() actually lock globallyJonathan Corbet
lg_lock_global() currently only acquires spinlocks for online CPUs, but it's meant to lock all possible CPUs. Lglock-protected resources may be associated with removed CPUs - and, indeed, that could happen with the per-superblock open files lists. At Nick's suggestion, change for_each_online_cpu() to for_each_possible_cpu() to protect accesses to those resources. Cc: Al Viro <viro@ZenIV.linux.org.uk> Acked-by: Nick Piggin <npiggin@kernel.dk> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>