user/sven/linux.git/include/uapi, branch v4.3-rc2

Merge branch 'akpm' (patches from Andrew)

2015-09-12T02:34:09Z

Merge fourth patch-bomb from Andrew Morton: - sys_membarier syscall - seq_file interface changes - a few misc fixups * emailed patches from Andrew Morton : revert "ocfs2/dlm: use list_for_each_entry instead of list_for_each" mm/early_ioremap: add explicit #include of asm/early_ioremap.h fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void selftests: enhance membarrier syscall test selftests: add membarrier syscall test sys_membarrier(): system-wide memory barrier (generic, x86) MODSIGN: fix a compilation warning in extract-cert

Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

2015-09-12T02:00:42Z

Pull SCSI target updates from Nicholas Bellinger: "Here are the outstanding target-pending updates for v4.3-rc1. Mostly bug-fixes and minor changes this round. The fallout from the big v4.2-rc1 RCU conversion have (thus far) been minimal. The highlights this round include: - Move sense handling routines into scsi_common code (Sagi) - Return ABORTED_COMMAND sense key for PI errors (Sagi) - Add tpg_enabled_sendtargets attribute for disabled iscsi-target discovery (David) - Shrink target struct se_cmd by rearranging fields (Roland) - Drop iSCSI use of mutex around max_cmd_sn increment (Roland) - Replace iSCSI __kernel_sockaddr_storage with sockaddr_storage (Andy + Chris) - Honor fabric max_data_sg_nents I/O transfer limit (Arun + Himanshu + nab) - Fix EXTENDED_COPY >= v4.1 regression OOPsen (Alex + nab)" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (37 commits) target: use stringify.h instead of own definition target/user: Fix UFLAG_UNKNOWN_OP handling target: Remove no-op conditional target/user: Remove unused variable target: Fix max_cmd_sn increment w/o cmdsn mutex regressions target: Attach EXTENDED_COPY local I/O descriptors to xcopy_pt_sess target/qla2xxx: Honor max_data_sg_nents I/O transfer limit target/iscsi: Replace __kernel_sockaddr_storage with sockaddr_storage target/iscsi: Replace conn->login_ip with login_sockaddr target/iscsi: Keep local_ip as the actual sockaddr target/iscsi: Fix np_ip bracket issue by removing np_ip target: Drop iSCSI use of mutex around max_cmd_sn increment qla2xxx: Update tcm_qla2xxx module description to 24xx+ iscsi-target: Add tpg_enabled_sendtargets for disabled discovery drivers: target: Drop unlikely before IS_ERR(_OR_NULL) target: check DPO/FUA usage for COMPARE AND WRITE target: Shrink struct se_cmd by rearranging fields target: Remove cmd->se_ordered_id (unused except debug log lines) target: add support for START_STOP_UNIT SCSI opcode target: improve unsupported opcode message ...

sys_membarrier(): system-wide memory barrier (generic, x86)

2015-09-11T22:21:34Z

Here is an implementation of a new system call, sys_membarrier(), which executes a memory barrier on all threads running on the system. It is implemented by calling synchronize_sched(). It can be used to distribute the cost of user-space memory barriers asymmetrically by transforming pairs of memory barriers into pairs consisting of sys_membarrier() and a compiler barrier. For synchronization primitives that distinguish between read-side and write-side (e.g. userspace RCU [1], rwlocks), the read-side can be accelerated significantly by moving the bulk of the memory barrier overhead to the write-side. The existing applications of which I am aware that would be improved by this system call are as follows: * Through Userspace RCU library (http://urcu.so) - DNS server (Knot DNS) https://www.knot-dns.cz/ - Network sniffer (http://netsniff-ng.org/) - Distributed object storage (https://sheepdog.github.io/sheepdog/) - User-space tracing (http://lttng.org) - Network storage system (https://www.gluster.org/) - Virtual routers (https://events.linuxfoundation.org/sites/events/files/slides/DPDK_RCU_0MQ.pdf) - Financial software (https://lkml.org/lkml/2015/3/23/189) Those projects use RCU in userspace to increase read-side speed and scalability compared to locking. Especially in the case of RCU used by libraries, sys_membarrier can speed up the read-side by moving the bulk of the memory barrier cost to synchronize_rcu(). * Direct users of sys_membarrier - core dotnet garbage collector (https://github.com/dotnet/coreclr/issues/198) Microsoft core dotnet GC developers are planning to use the mprotect() side-effect of issuing memory barriers through IPIs as a way to implement Windows FlushProcessWriteBuffers() on Linux. They are referring to sys_membarrier in their github thread, specifically stating that sys_membarrier() is what they are looking for. To explain the benefit of this scheme, let's introduce two example threads: Thread A (non-frequent, e.g. executing liburcu synchronize_rcu()) Thread B (frequent, e.g. executing liburcu rcu_read_lock()/rcu_read_unlock()) In a scheme where all smp_mb() in thread A are ordering memory accesses with respect to smp_mb() present in Thread B, we can change each smp_mb() within Thread A into calls to sys_membarrier() and each smp_mb() within Thread B into compiler barriers "barrier()". Before the change, we had, for each smp_mb() pairs: Thread A Thread B previous mem accesses previous mem accesses smp_mb() smp_mb() following mem accesses following mem accesses After the change, these pairs become: Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses As we can see, there are two possible scenarios: either Thread B memory accesses do not happen concurrently with Thread A accesses (1), or they do (2). 1) Non-concurrent Thread A vs Thread B accesses: Thread A Thread B prev mem accesses sys_membarrier() follow mem accesses prev mem accesses barrier() follow mem accesses In this case, thread B accesses will be weakly ordered. This is OK, because at that point, thread A is not particularly interested in ordering them with respect to its own accesses. 2) Concurrent Thread A vs Thread B accesses Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses In this case, thread B accesses, which are ensured to be in program order thanks to the compiler barrier, will be "upgraded" to full smp_mb() by synchronize_sched(). * Benchmarks On Intel Xeon E5405 (8 cores) (one thread is calling sys_membarrier, the other 7 threads are busy looping) 1000 non-expedited sys_membarrier calls in 33s =3D 33 milliseconds/call. * User-space user of this system call: Userspace RCU library Both the signal-based and the sys_membarrier userspace RCU schemes permit us to remove the memory barrier from the userspace RCU rcu_read_lock() and rcu_read_unlock() primitives, thus significantly accelerating them. These memory barriers are replaced by compiler barriers on the read-side, and all matching memory barriers on the write-side are turned into an invocation of a memory barrier on all active threads in the process. By letting the kernel perform this synchronization rather than dumbly sending a signal to every process threads (as we currently do), we diminish the number of unnecessary wake ups and only issue the memory barriers on active threads. Non-running threads do not need to execute such barrier anyway, because these are implied by the scheduler context switches. Results in liburcu: Operations in 10s, 6 readers, 2 writers: memory barriers in reader: 1701557485 reads, 2202847 writes signal-based scheme: 9830061167 reads, 6700 writes sys_membarrier: 9952759104 reads, 425 writes sys_membarrier (dyn. check): 7970328887 reads, 425 writes The dynamic sys_membarrier availability check adds some overhead to the read-side compared to the signal-based scheme, but besides that, sys_membarrier slightly outperforms the signal-based scheme. However, this non-expedited sys_membarrier implementation has a much slower grace period than signal and memory barrier schemes. Besides diminishing the number of wake-ups, one major advantage of the membarrier system call over the signal-based scheme is that it does not need to reserve a signal. This plays much more nicely with libraries, and with processes injected into for tracing purposes, for which we cannot expect that signals will be unused by the application. An expedited version of this system call can be added later on to speed up the grace period. Its implementation will likely depend on reading the cpu_curr()->mm without holding each CPU's rq lock. This patch adds the system call to x86 and to asm-generic. [1] http://urcu.so membarrier(2) man page: MEMBARRIER(2) Linux Programmer's Manual MEMBARRIER(2) NAME membarrier - issue memory barriers on a set of threads SYNOPSIS #include int membarrier(int cmd, int flags); DESCRIPTION The cmd argument is one of the following: MEMBARRIER_CMD_QUERY Query the set of supported commands. It returns a bitmask of supported commands. MEMBARRIER_CMD_SHARED Execute a memory barrier on all threads running on the system. Upon return from system call, the caller thread is ensured that all running threads have passed through a state where all memory accesses to user-space addresses match program order between entry to and return from the system call (non-running threads are de facto in such a state). This covers threads from all pro=E2=80=90 cesses running on the system. This command returns 0. The flags argument needs to be 0. For future extensions. All memory accesses performed in program order from each targeted thread is guaranteed to be ordered with respect to sys_membarrier(). If we use the semantic "barrier()" to represent a compiler barrier forcing memory accesses to be performed in program order across the barrier, and smp_mb() to represent explicit memory barriers forcing full memory ordering across the barrier, we have the following ordering table for each pair of barrier(), sys_membarrier() and smp_mb(): The pair ordering is detailed as (O: ordered, X: not ordered): barrier() smp_mb() sys_membarrier() barrier() X X O smp_mb() X O O sys_membarrier() O O O RETURN VALUE On success, these system calls return zero. On error, -1 is returned, and errno is set appropriately. For a given command, with flags argument set to 0, this system call is guaranteed to always return the same value until reboot. ERRORS ENOSYS System call is not implemented. EINVAL Invalid arguments. Linux 2015-04-15 MEMBARRIER(2) Signed-off-by: Mathieu Desnoyers Reviewed-by: Paul E. McKenney Reviewed-by: Josh Triplett Cc: KOSAKI Motohiro Cc: Steven Rostedt Cc: Nicholas Miell Cc: Ingo Molnar Cc: Alan Cox Cc: Lai Jiangshan Cc: Stephen Hemminger Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: David Howells Cc: Pranith Kumar Cc: Michael Kerrisk Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux

2015-09-11T16:35:56Z

Pull drm fixes from Dave Airlie: "Just a bunch of fixes to squeeze in before -rc1: - three nouveau regression fixes - one qxl regression fix - a bunch of i915 fixes ... and some core displayport/atomic fixes" * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: drm/nouveau/device: enable c800 quirk for tecra w50 drm/nouveau/clk/gt215: Unbreak engine pausing for GT21x/MCP7x drm/nouveau/gr/nv04: fix big endian setting on gr context drm/qxl: validate monitors config modes drm/i915: Allow DSI dual link to be configured on any pipe drm/i915: Don't try to use DDR DVFS on CHV when disabled in the BIOS drm/i915: Fix CSR MMIO address check drm/i915: Limit the number of loops for reading a split 64bit register drm/i915: Fix broken mst get_hw_state. drm/i915: Pass hpd_status_i915[] to intel_get_hpd_pins() in pre-g4x uapi/drm/i915_drm.h: fix userspace compilation. drm/i915: Always mark the object as dirty when used by the GPU drm/dp: Add dp_aux_i2c_speed_khz module param to set the assume i2c bus speed drm/dp: Adjust i2c-over-aux retry count based on message size and i2c bus speed drm/dp: Define AUX_RETRY_INTERVAL as 500 us drm/atomic: Fix bookkeeping with TEST_ONLY, v3.

target: use stringify.h instead of own definition

2015-09-11T07:32:36Z

Signed-off-by: David Disseldorp Acked-by: Andy Grover Signed-off-by: Nicholas Bellinger

Merge branch 'akpm' (patches from Andrew)

2015-09-11T01:19:42Z

Merge third patch-bomb from Andrew Morton: - even more of the rest of MM - lib/ updates - checkpatch updates - small changes to a few scruffy filesystems - kmod fixes/cleanups - kexec updates - a dma-mapping cleanup series from hch * emailed patches from Andrew Morton : (81 commits) dma-mapping: consolidate dma_set_mask dma-mapping: consolidate dma_supported dma-mapping: cosolidate dma_mapping_error dma-mapping: consolidate dma_{alloc,free}_noncoherent dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent} mm: use vma_is_anonymous() in create_huge_pmd() and wp_huge_pmd() mm: make sure all file VMAs have ->vm_ops set mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff() mm: mark most vm_operations_struct const namei: fix warning while make xmldocs caused by namei.c ipc: convert invalid scenarios to use WARN_ON zlib_deflate/deftree: remove bi_reverse() lib/decompress_unlzma: Do a NULL check for pointer lib/decompressors: use real out buf size for gunzip with kernel fs/affs: make root lookup from blkdev logical size sysctl: fix int -> unsigned long assignments in INT_MIN case kexec: export KERNEL_IMAGE_SIZE to vmcoreinfo kexec: align crash_notes allocation to make it be inside one physical page kexec: remove unnecessary test in kimage_alloc_crash_control_pages() kexec: split kexec_load syscall from kexec core code ...

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2015-09-10T23:42:49Z

Pull more kvm updates from Paolo Bonzini: "ARM: - Full debug support for arm64 - Active state switching for timer interrupts - Lazy FP/SIMD save/restore for arm64 - Generic ARMv8 target PPC: - Book3S: A few bug fixes - Book3S: Allow micro-threading on POWER8 x86: - Compiler warnings Generic: - Adaptive polling for guest halt" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (49 commits) kvm: irqchip: fix memory leak kvm: move new trace event outside #ifdef CONFIG_KVM_ASYNC_PF KVM: trace kvm_halt_poll_ns grow/shrink KVM: dynamic halt-polling KVM: make halt_poll_ns per-vCPU Silence compiler warning in arch/x86/kvm/emulate.c kvm: compile process_smi_save_seg_64() only for x86_64 KVM: x86: avoid uninitialized variable warning KVM: PPC: Book3S: Fix typo in top comment about locking KVM: PPC: Book3S: Fix size of the PSPB register KVM: PPC: Book3S HV: Exit on H_DOORBELL if HOST_IPI is set KVM: PPC: Book3S HV: Fix race in starting secondary threads KVM: PPC: Book3S: correct width in XER handling KVM: PPC: Book3S HV: Fix preempted vcore stolen time calculation KVM: PPC: Book3S HV: Fix preempted vcore list locking KVM: PPC: Book3S HV: Implement H_CLEAR_REF and H_CLEAR_MOD KVM: PPC: Book3S HV: Fix bug in dirty page tracking KVM: PPC: Book3S HV: Fix race in reading change bit when removing HPTE KVM: PPC: Book3S HV: Implement dynamic micro-threading on POWER8 KVM: PPC: Book3S HV: Make use of unused threads when running guests ...

Merge tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2015-09-10T23:21:11Z

Pull xen terminology fixes from David Vrabel: "Use the correct GFN/BFN terms more consistently" * tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/xenbus: Rename the variable xen_store_mfn to xen_store_gfn xen/privcmd: Further s/MFN/GFN/ clean-up hvc/xen: Further s/MFN/GFN clean-up video/xen-fbfront: Further s/MFN/GFN clean-up xen/tmem: Use xen_page_to_gfn rather than pfn_to_gfn xen: Use correctly the Xen memory terminologies arm/xen: implement correctly pfn_to_mfn xen: Make clear that swiotlb and biomerge are dealing with DMA address

Merge branch 'next' of git://git.monstr.eu/linux-2.6-microblaze

2015-09-10T23:20:00Z

Pull microblaze update from Michal Simek. * 'next' of git://git.monstr.eu/linux-2.6-microblaze: elf-em.h: move EM_MICROBLAZE to the common header

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2015-09-10T20:53:15Z

Pull networking fixes from David Miller: 1) Fix out-of-bounds array access in netfilter ipset, from Jozsef Kadlecsik. 2) Use correct free operation on netfilter conntrack templates, from Daniel Borkmann. 3) Fix route leak in SCTP, from Marcelo Ricardo Leitner. 4) Fix sizeof(pointer) in mac80211, from Thierry Reding. 5) Fix cache pointer comparison in ip6mr leading to missed unlock of mrt_lock. From Richard Laing. 6) rds_conn_lookup() needs to consider network namespace in key comparison, from Sowmini Varadhan. 7) Fix deadlock in TIPC code wrt broadcast link wakeups, from Kolmakov Dmitriy. 8) Fix fd leaks in bpf syscall, from Daniel Borkmann. 9) Fix error recovery when installing ipv6 multipath routes, we would delete the old route before we would know if we could fully commit to the new set of nexthops. Fix from Roopa Prabhu. 10) Fix run-time suspend problems in r8152, from Hayes Wang. 11) In fec, don't program the MAC address into the chip when the clocks are gated off. From Fugang Duan. 12) Fix poll behavior for netlink sockets when using rx ring mmap, from Daniel Borkmann. 13) Don't allocate memory with GFP_KERNEL from get_stats64 in r8169 driver, from Corinna Vinschen. 14) In TCP Cubic congestion control, handle idle periods better where we are application limited, in order to keep cwnd from growing out of control. From Eric Dumzet. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits) tcp_cubic: better follow cubic curve after idle period tcp: generate CA_EVENT_TX_START on data frames xen-netfront: respect user provided max_queues xen-netback: respect user provided max_queues r8169: Fix sleeping function called during get_stats64, v2 ether: add IEEE 1722 ethertype - TSN netlink, mmap: fix edge-case leakages in nf queue zero-copy netlink, mmap: don't walk rx ring on poll if receive queue non-empty cxgb4: changes for new firmware 1.14.4.0 net: fec: add netif status check before set mac address r8152: fix the runtime suspend issues r8152: split DRIVER_VERSION ipv6: fix ifnullfree.cocci warnings add microchip LAN88xx phy driver stmmac: fix check for phydev being open net: qlcnic: delete redundant memsets net: mv643xx_eth: use kzalloc net: jme: use kzalloc() instead of kmalloc+memset net: cavium: liquidio: use kzalloc in setup_glist() net: ipv6: use common fib_default_rule_pref ...