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2017-01-17virtio: don't set VIRTIO_NET_HDR_F_DATA_VALID on xmitRolf Neugebauer
This patch part reverts fd2a0437dc33 and e858fae2b0b8 which introduced a subtle change in how the virtio_net flags are derived from the SKBs ip_summed field. With the above commits, the flags are set to VIRTIO_NET_HDR_F_DATA_VALID when ip_summed == CHECKSUM_UNNECESSARY, thus treating it differently to ip_summed == CHECKSUM_NONE, which should be the same. Further, the virtio spec 1.0 / CS04 explicitly says that VIRTIO_NET_HDR_F_DATA_VALID must not be set by the driver. Fixes: fd2a0437dc33 ("virtio_net: introduce virtio_net_hdr_{from,to}_skb") Fixes: e858fae2b0b8 (" virtio_net: use common code for virtio_net_hdr and skb GSO conversion") Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-17taint/module: Fix problems when out-of-kernel driver defines true or falseLarry Finger
Commit 7fd8329ba502 ("taint/module: Clean up global and module taint flags handling") used the key words true and false as character members of a new struct. These names cause problems when out-of-kernel modules such as VirtualBox include their own definitions of true and false. Fixes: 7fd8329ba502 ("taint/module: Clean up global and module taint flags handling") Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Petr Mladek <pmladek@suse.com> Cc: Jessica Yu <jeyu@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jessica Yu <jeyu@redhat.com>
2017-01-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Handle multicast packets properly in fast-RX path of mac80211, from Johannes Berg. 2) Because of a logic bug, the user can't actually force SW checksumming on r8152 devices. This makes diagnosis of hw checksumming bugs really annoying. Fix from Hayes Wang. 3) VXLAN route lookup does not take the source and destination ports into account, which means IPSEC policies cannot be matched properly. Fix from Martynas Pumputis. 4) Do proper RCU locking in netvsc callbacks, from Stephen Hemminger. 5) Fix SKB leaks in mlxsw driver, from Arkadi Sharshevsky. 6) If lwtunnel_fill_encap() fails, we do not abort the netlink message construction properly in fib_dump_info(), from David Ahern. 7) Do not use kernel stack for DMA buffers in atusb driver, from Stefan Schmidt. 8) Openvswitch conntack actions need to maintain a correct checksum, fix from Lance Richardson. 9) ax25_disconnect() is missing a check for ax25->sk being NULL, in fact it already checks this, but not in all of the necessary spots. Fix from Basil Gunn. 10) Action GET operations in the packet scheduler can erroneously bump the reference count of the entry, making it unreleasable. Fix from Jamal Hadi Salim. Jamal gives a great set of example command lines that trigger this in the commit message. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (46 commits) net sched actions: fix refcnt when GETing of action after bind net/mlx4_core: Eliminate warning messages for SRQ_LIMIT under SRIOV net/mlx4_core: Fix when to save some qp context flags for dynamic VST to VGT transitions net/mlx4_core: Fix racy CQ (Completion Queue) free net: stmmac: don't use netdev_[dbg, info, ..] before net_device is registered net/mlx5e: Fix a -Wmaybe-uninitialized warning ax25: Fix segfault after sock connection timeout bpf: rework prog_digest into prog_tag tipc: allocate user memory with GFP_KERNEL flag net: phy: dp83867: allow RGMII_TXID/RGMII_RXID interface types ip6_tunnel: Account for tunnel header in tunnel MTU mld: do not remove mld souce list info when set link down be2net: fix MAC addr setting on privileged BE3 VFs be2net: don't delete MAC on close on unprivileged BE3 VFs be2net: fix status check in be_cmd_pmac_add() cpmac: remove hopeless #warning ravb: do not use zero-length alignment DMA descriptor mlx4: do not call napi_schedule() without care openvswitch: maintain correct checksum state in conntrack actions tcp: fix tcp_fastopen unaligned access complaints on sparc ...
2017-01-17blk-mq-sched: allow setting of default IO schedulerJens Axboe
Add Kconfig entries to manage what devices get assigned an MQ scheduler, and add a blk-mq flag for drivers to opt out of scheduling. The latter is useful for admin type queues that still allocate a blk-mq queue and tag set, but aren't use for normal IO. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17blk-mq-sched: add framework for MQ capable IO schedulersJens Axboe
This adds a set of hooks that intercepts the blk-mq path of allocating/inserting/issuing/completing requests, allowing us to develop a scheduler within that framework. We reuse the existing elevator scheduler API on the registration side, but augment that with the scheduler flagging support for the blk-mq interfce, and with a separate set of ops hooks for MQ devices. We split driver and scheduler tags, so we can run the scheduling independently of device queue depth. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17blk-mq: add support for carrying internal tag information in blk_qc_tJens Axboe
No functional change in this patch, just in preparation for having two types of tags available to the block layer for a single request. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17blk-mq: un-export blk_mq_free_hctx_request()Jens Axboe
It's only used in blk-mq, kill it from the main exported header and kill the symbol export as well. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17block: move existing elevator ops to unionJens Axboe
Prep patch for adding MQ ops as well, since doing anon unions with named initializers doesn't work on older compilers. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17of: base: add support to find the level of the last cacheSudeep Holla
It is useful to have helper function just to get the number of cache levels for a given logical cpu. We can obtain the same by just checking the level at which the last cache is present. This patch adds support to find the level of the last cache for a given cpu. It will be used on ARM64 platform where the device tree provides the information for the additional non-architected/transparent/external last level caches that are not integrated with the processors. Cc: Mark Rutland <mark.rutland@arm.com> Suggested-by: Rob Herring <robh+dt@kernel.org> Acked-by: Rob Herring <robh+dt@kernel.org> Tested-by: Tan Xiaojun <tanxiaojun@huawei.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> [will: use u32 instead of int for cache_level] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-16firmware: qcom_scm: Add set remote state APIAndy Gross
This patch adds a set remote state SCM API. This will be used by the Venus and GPU subsystems to set state on the remote processors. This work was based on two patch sets by Jordan Crouse and Stanimir Varbanov. Signed-off-by: Andy Gross <andy.gross@linaro.org>
2017-01-16firmware: qcom: scm: Add empty functions to help compile testingStanimir Varbanov
This will help to compile testing drivers which depends on scm functions with COMPILE_TEST Kconfig option. Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Andy Gross <andy.gross@linaro.org>
2017-01-16bpf: rework prog_digest into prog_tagDaniel Borkmann
Commit 7bd509e311f4 ("bpf: add prog_digest and expose it via fdinfo/netlink") was recently discussed, partially due to admittedly suboptimal name of "prog_digest" in combination with sha1 hash usage, thus inevitably and rightfully concerns about its security in terms of collision resistance were raised with regards to use-cases. The intended use cases are for debugging resp. introspection only for providing a stable "tag" over the instruction sequence that both kernel and user space can calculate independently. It's not usable at all for making a security relevant decision. So collisions where two different instruction sequences generate the same tag can happen, but ideally at a rather low rate. The "tag" will be dumped in hex and is short enough to introspect in tracepoints or kallsyms output along with other data such as stack trace, etc. Thus, this patch performs a rename into prog_tag and truncates the tag to a short output (64 bits) to make it obvious it's not collision-free. Should in future a hash or facility be needed with a security relevant focus, then we can think about requirements, constraints, etc that would fit to that situation. For now, rework the exposed parts for the current use cases as long as nothing has been released yet. Tested on x86_64 and s390x. Fixes: 7bd509e311f4 ("bpf: add prog_digest and expose it via fdinfo/netlink") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-16Merge tag 'nfsd-4.10-1' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
Pull nfsd fixes from Bruce Fields: "Miscellaneous nfsd bugfixes, one for a 4.10 regression, three for older bugs" * tag 'nfsd-4.10-1' of git://linux-nfs.org/~bfields/linux: svcrdma: avoid duplicate dma unmapping during error recovery sunrpc: don't call sleeping functions from the notifier block callbacks svcrpc: don't leak contexts on PROC_DESTROY nfsd: fix supported attributes for acl & labels
2017-01-16Merge 4.10-rc4 into char-misc-nextGreg Kroah-Hartman
We want the char/misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-16Merge 4.10-rc4 into tty-nextGreg Kroah-Hartman
We want the serial/tty fixes in here as well to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-16Merge 4.10-rc4 into driver-core-nextGreg Kroah-Hartman
We want the sysfs file revert and other fixes in here as well for testing. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-16cpu/hotplug: Provide dynamic range for prepare stageThomas Gleixner
Mathieu reported that the LTTNG modules are broken as of 4.10-rc1 due to the removal of the cpu hotplug notifiers. Usually I don't care much about out of tree modules, but LTTNG is widely used in distros. There are two ways to solve that: 1) Reserve a hotplug state for LTTNG 2) Add a dynamic range for the prepare states. While #1 is the simplest solution, #2 is the proper one as we can convert in tree users, which do not care about ordering, to the dynamic range as well. Add a dynamic range which allows LTTNG to request states in the prepare stage. Reported-and-tested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Sewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701101353010.3401@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-16Merge branch 'rcu/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into rcu/urgent Pull an urgent RCU fix from Paul E. McKenney: "This series contains a pair of commits that permit RCU synchronous grace periods (synchronize_rcu() and friends) to work correctly throughout boot. This eliminates the current "dead time" starting when the scheduler spawns its first taks and ending when the last of RCU's kthreads is spawned (this last happens during early_initcall() time). Although RCU's synchronous grace periods have long been documented as not working during this time, prior to 4.9, the expedited grace periods worked by accident, and some ACPI code came to rely on this unintentional behavior. (Note that this unintentional behavior was -not- reliable. For example, failures from ACPI could occur on !SMP systems and on systems booting with the rcu_normal kernel boot parameter.) Either way, there is a bug that needs fixing, and the 4.9 switch of RCU's expedited grace periods to workqueues could be considered to have caused a regression. This series therefore makes RCU's expedited grace periods operate correctly throughout the boot process. This has been demonstrated to fix the problems ACPI was encountering, and has the added longer-term benefit of simplifying RCU's behavior." Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-15Input: mpr121 - switch to device tree probeAkinobu Mita
This driver currently only supports legacy platform data probe. This change adds device tree support and gets rid of platform data probe code since no one is actually using mpr121 platform data in the mainline. The device tree property parsing code is based on the work of atmel_captouch driver. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-01-15Merge branch 'i2c/for-current' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c fixes from Wolfram Sang: "Bugfixes for I2C. Mostly core this time which is a bit unusual but nothing really scary in there" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: piix4: Avoid race conditions with IMC i2c: fix spelling mistake: "insufficent" -> "insufficient" i2c: print correct device invalid address i2c: do not enable fall back to Host Notify by default i2c: fix kernel memory disclosure in dev interface
2017-01-15Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc race fixes uncovered by fuzzing efforts, a Sparse fix, two PMU driver fixes, plus miscellanous tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Reject non sampling events with precise_ip perf/x86/intel: Account interrupts for PEBS errors perf/core: Fix concurrent sys_perf_event_open() vs. 'move_group' race perf/core: Fix sys_perf_event_open() vs. hotplug perf/x86/intel: Use ULL constant to prevent undefined shift behaviour perf/x86/intel/uncore: Fix hardcoded socket 0 assumption in the Haswell init code perf/x86: Set pmu->module in Intel PMU modules perf probe: Fix to probe on gcc generated symbols for offline kernel perf probe: Fix --funcs to show correct symbols for offline module perf symbols: Robustify reading of build-id from sysfs perf tools: Install tools/lib/traceevent plugins with install-bin tools lib traceevent: Fix prev/next_prio for deadline tasks perf record: Fix --switch-output documentation and comment perf record: Make __record_options static tools lib subcmd: Add OPT_STRING_OPTARG_SET option perf probe: Fix to get correct modname from elf header samples/bpf trace_output_user: Remove duplicate sys/ioctl.h include samples/bpf sock_example: Avoid getting ethhdr from two includes perf sched timehist: Show total scheduling time
2017-01-15Merge branch 'efi-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI fixes from Ingo Molnar: "A number of regression fixes: - Fix a boot hang on machines that have somewhat unusual memory map entries of phys_addr=0x0 num_pages=0, which broke due to a recent commit. This commit got cherry-picked from the v4.11 queue because the bug is affecting real machines. - Fix a boot hang also reported by KASAN, caused by incorrect init ordering introduced by a recent optimization. - Fix a recent robustification fix to allocate_new_fdt_and_exit_boot() that introduced an invalid assumption. Neither bugs were seen in the wild AFAIK" * 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi/x86: Prune invalid memory map entries and fix boot regression x86/efi: Don't allocate memmap through memblock after mm_init() efi/libstub/arm*: Pass latest memory map to the kernel
2017-01-14rcu: Narrow early boot window of illegal synchronous grace periodsPaul E. McKenney
The current preemptible RCU implementation goes through three phases during bootup. In the first phase, there is only one CPU that is running with preemption disabled, so that a no-op is a synchronous grace period. In the second mid-boot phase, the scheduler is running, but RCU has not yet gotten its kthreads spawned (and, for expedited grace periods, workqueues are not yet running. During this time, any attempt to do a synchronous grace period will hang the system (or complain bitterly, depending). In the third and final phase, RCU is fully operational and everything works normally. This has been OK for some time, but there has recently been some synchronous grace periods showing up during the second mid-boot phase. This code worked "by accident" for awhile, but started failing as soon as expedited RCU grace periods switched over to workqueues in commit 8b355e3bc140 ("rcu: Drive expedited grace periods from workqueue"). Note that the code was buggy even before this commit, as it was subject to failure on real-time systems that forced all expedited grace periods to run as normal grace periods (for example, using the rcu_normal ksysfs parameter). The callchain from the failure case is as follows: early_amd_iommu_init() |-> acpi_put_table(ivrs_base); |-> acpi_tb_put_table(table_desc); |-> acpi_tb_invalidate_table(table_desc); |-> acpi_tb_release_table(...) |-> acpi_os_unmap_memory |-> acpi_os_unmap_iomem |-> acpi_os_map_cleanup |-> synchronize_rcu_expedited The kernel showing this callchain was built with CONFIG_PREEMPT_RCU=y, which caused the code to try using workqueues before they were initialized, which did not go well. This commit therefore reworks RCU to permit synchronous grace periods to proceed during this mid-boot phase. This commit is therefore a fix to a regression introduced in v4.9, and is therefore being put forward post-merge-window in v4.10. This commit sets a flag from the existing rcu_scheduler_starting() function which causes all synchronous grace periods to take the expedited path. The expedited path now checks this flag, using the requesting task to drive the expedited grace period forward during the mid-boot phase. Finally, this flag is updated by a core_initcall() function named rcu_exp_runtime_mode(), which causes the runtime codepaths to be used. Note that this arrangement assumes that tasks are not sent POSIX signals (or anything similar) from the time that the first task is spawned through core_initcall() time. Fixes: 8b355e3bc140 ("rcu: Drive expedited grace periods from workqueue") Reported-by: "Zheng, Lv" <lv.zheng@intel.com> Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Stan Kain <stan.kain@gmail.com> Tested-by: Ivan <waffolz@hotmail.com> Tested-by: Emanuel Castelo <emanuel.castelo@gmail.com> Tested-by: Bruno Pesavento <bpesavento@infinito.it> Tested-by: Borislav Petkov <bp@suse.de> Tested-by: Frederic Bezies <fredbezies@gmail.com> Cc: <stable@vger.kernel.org> # 4.9.0-
2017-01-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fixes from Al Viro. The most notable fix here is probably the fix for a splice regression ("fix a fencepost error in pipe_advance()") noticed by Alan Wylie. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix a fencepost error in pipe_advance() coredump: Ensure proper size of sparse core files aio: fix lock dep warning tmpfs: clear S_ISGID when setting posix ACLs
2017-01-14Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: - the virtio_blk stack DMA corruption fix from Christoph, fixing and issue with VMAP stacks. - O_DIRECT blkbits calculation fix from Chandan. - discard regression fix from Christoph. - queue init error handling fixes for nbd and virtio_blk, from Omar and Jeff. - two small nvme fixes, from Christoph and Guilherme. - rename of blk_queue_zone_size and bdev_zone_size to _sectors instead, to more closely follow what we do in other places in the block layer. This interface is new for this series, so let's get the naming right before releasing a kernel with this feature. From Damien. * 'for-linus' of git://git.kernel.dk/linux-block: block: don't try to discard from __blkdev_issue_zeroout sd: remove __data_len hack for WRITE SAME nvme: use blk_rq_payload_bytes scsi: use blk_rq_payload_bytes block: add blk_rq_payload_bytes block: Rename blk_queue_zone_size and bdev_zone_size nvme: apply DELAY_BEFORE_CHK_RDY quirk at probe time too nvme-rdma: fix nvme_rdma_queue_is_ready virtio_blk: fix panic in initialization error path nbd: blk_mq_init_queue returns an error code on failure, not NULL virtio_blk: avoid DMA to stack for the sense buffer do_direct_IO: Use inode->i_blkbits to compute block count to be cleaned
2017-01-14coredump: Ensure proper size of sparse core filesDave Kleikamp
If the last section of a core file ends with an unmapped or zero page, the size of the file does not correspond with the last dump_skip() call. gdb complains that the file is truncated and can be confusing to users. After all of the vma sections are written, make sure that the file size is no smaller than the current file position. This problem can be demonstrated with gdb's bigcore testcase on the sparc architecture. Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-01-14Merge tag 'mac80211-next-for-davem-2017-01-13' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next Johannes Berg says: ==================== For 4.11, we seem to have more than in the past few releases: * socket owner support for connections, so when the wifi manager (e.g. wpa_supplicant) is killed, connections are torn down - wpa_supplicant is critical to managing certain operations, and can opt in to this where applicable * minstrel & minstrel_ht updates to be more efficient (time and space) * set wifi_acked/wifi_acked_valid for skb->destructor use in the kernel, which was already available to userspace * don't indicate new mesh peers that might be used if there's no room to add them * multicast-to-unicast support in mac80211, for better medium usage (since unicast frames can use *much* higher rates, by ~3 orders of magnitude) * add API to read channel (frequency) limitations from DT * add infrastructure to allow randomizing public action frames for MAC address privacy (still requires driver support) * many cleanups and small improvements/fixes across the board ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-14locking/mutex, sched/wait: Fix the mutex_lock_io_nested() defineIngo Molnar
Mike noticed this bogosity: > > +# define mutex_lock_nest_io(lock, nest_lock) mutex_io(lock) > ^^^^^^^^^^^^^^ typo This new locking API is not used yet, so this didn't trigger in testing. Fix it. Reported-by: Mike Galbraith <efault@gmx.de> Cc: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: adilger.kernel@dilger.ca Cc: jack@suse.com Cc: kernel-team@fb.com Cc: mingbo@fb.com Cc: tytso@mit.edu Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14efi/x86: Prune invalid memory map entries and fix boot regressionPeter Jones
Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW (2.28), include memory map entries with phys_addr=0x0 and num_pages=0. These machines fail to boot after the following commit, commit 8e80632fb23f ("efi/esrt: Use efi_mem_reserve() and avoid a kmalloc()") Fix this by removing such bogus entries from the memory map. Furthermore, currently the log output for this case (with efi=debug) looks like: [ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[0x0000000000000000-0xffffffffffffffff] (0MB) This is clearly wrong, and also not as informative as it could be. This patch changes it so that if we find obviously invalid memory map entries, we print an error and skip those entries. It also detects the display of the address range calculation overflow, so the new output is: [ 0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries: [ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[0x0000000000000000-0x0000000000000000] (invalid) It also detects memory map sizes that would overflow the physical address, for example phys_addr=0xfffffffffffff000 and num_pages=0x0200000000000001, and prints: [ 0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries: [ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[phys_addr=0xfffffffffffff000-0x20ffffffffffffffff] (invalid) It then removes these entries from the memory map. Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [ardb: refactor for clarity with no functional changes, avoid PAGE_SHIFT] Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> [Matt: Include bugzilla info in commit log] Cc: <stable@vger.kernel.org> # v4.9+ Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://bugzilla.kernel.org/show_bug.cgi?id=191121 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/ww_mutex: Turn off __must_check for nowIngo Molnar
With the ww_mutex inline wrappers gone there's a lot of dormant anti-patterns emerging in an x86 allyesconfig build: kernel/locking/test-ww_mutex.c:80:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] kernel/locking/test-ww_mutex.c:55:3: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] kernel/locking/test-ww_mutex.c:134:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] kernel/locking/test-ww_mutex.c:213:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] kernel/locking/test-ww_mutex.c:177:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] kernel/locking/test-ww_mutex.c:266:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:213:19: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] lib/locking-selftest.c:211:20: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] drivers/gpu/drm/drm_modeset_lock.c:430:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c:70:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] drivers/gpu/drm/vgem/vgem_fence.c:193:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] drivers/gpu/drm/i915/i915_gem_batch_pool.c:125:4: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] drivers/gpu/drm/i915/i915_gem_execbuffer.c:1302:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] drivers/gpu/drm/radeon/radeon_prime.c:69:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] drivers/gpu/drm/nouveau/nouveau_prime.c:70:2: warning: ignoring return value of ‘ww_mutex_lock’, declared with attribute warn_unused_result [-Wunused-result] ... but we cannot just litter the kernel build log with such warnings. These need to be fixed separately - turn off the warning for now. Cc: Nicolai Hähnle <nicolai.haehnle@amd.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <dev@mblankhorst.nl> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/atomic, kref: Kill kref_sub()Peter Zijlstra
By general sentiment kref_sub() is a bad interface, make it go away. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/atomic, kref: Add kref_read()Peter Zijlstra
Since we need to change the implementation, stop exposing internals. Provide kref_read() to read the current reference count; typically used for debug messages. Kills two anti-patterns: atomic_read(&kref->refcount) kref->refcount.counter Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/atomic, kref: Add KREF_INIT()Peter Zijlstra
Since we need to change the implementation, stop exposing internals. Provide KREF_INIT() to allow static initialization of struct kref. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/ww_mutex: Fix compilation of __WW_MUTEX_INITIALIZERChris Wilson
From conflicting macro parameters, passing the wrong name to __MUTEX_INITIALIZER and a stray '\', #define __WW_MUTEX_INITIALIZER was very unhappy. One unnecessary change was to choose to pass &ww_class instead of implicitly taking the address of the class within the macro. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 1b375dc30710 ("mutex: Move ww_mutex definitions to ww_mutex.h") Link: http://lkml.kernel.org/r/20161201114711.28697-2-chris@chris-wilson.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14math64, timers: Fix 32bit mul_u64_u32_shr() and friendsPeter Zijlstra
It turns out that while GCC-4.4 manages to generate 32x32->64 mult instructions for the 32bit mul_u64_u32_shr() code, any GCC after that fails horribly. Fix this by providing an explicit mul_u32_u32() function which can be architcture provided. Reported-by: Chris Metcalf <cmetcalf@mellanox.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Chris Metcalf <cmetcalf@mellanox.com> [for tile] Cc: Christopher S. Hall <christopher.s.hall@intel.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: John Stultz <john.stultz@linaro.org> Cc: Laurent Vivier <lvivier@redhat.com> Cc: Liav Rehana <liavr@mellanox.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Parit Bhargava <prarit@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161209083011.GD15765@worktop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/mutex, sched/wait: Add mutex_lock_io()Tejun Heo
We sometimes end up propagating IO blocking through mutexes; however, because there currently is no way of annotating mutex sleeps as iowait, there are cases where iowait and /proc/stat:procs_blocked report misleading numbers obscuring the actual state of the system. This patch adds mutex_lock_io() so that mutex sleeps can be marked as iowait in those cases. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: adilger.kernel@dilger.ca Cc: jack@suse.com Cc: kernel-team@fb.com Cc: mingbo@fb.com Cc: tytso@mit.edu Link: http://lkml.kernel.org/r/1477673892-28940-4-git-send-email-tj@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14sched/core: Separate out io_schedule_prepare() and io_schedule_finish()Tejun Heo
Now that IO schedule accounting is done inside __schedule(), io_schedule() can be split into three steps - prep, schedule, and finish - where the schedule part doesn't need any special annotation. This allows marking a sleep as iowait by simply wrapping an existing blocking function with io_schedule_prepare() and io_schedule_finish(). Because task_struct->in_iowait is single bit, the caller of io_schedule_prepare() needs to record and the pass its state to io_schedule_finish() to be safe regarding nesting. While this isn't the prettiest, these functions are mostly gonna be used by core functions and we don't want to use more space for ->in_iowait. While at it, as it's simple to do now, reimplement io_schedule() without unnecessarily going through io_schedule_timeout(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: adilger.kernel@dilger.ca Cc: jack@suse.com Cc: kernel-team@fb.com Cc: mingbo@fb.com Cc: tytso@mit.edu Link: http://lkml.kernel.org/r/1477673892-28940-3-git-send-email-tj@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14sched/clock: Delay switching sched_clock to stablePeter Zijlstra
Currently we switch to the stable sched_clock if we guess the TSC is usable, and then switch back to the unstable path if it turns out TSC isn't stable during SMP bringup after all. Delay switching to the stable path until after SMP bringup is complete. This way we'll avoid switching during the time we detect the worst of the TSC offences. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14sched/clock, clocksource: Add optional cs::mark_unstable() methodThomas Gleixner
PeterZ reported that we'd fail to mark the TSC unstable when the clocksource watchdog finds it unsuitable. Allow a clocksource to run a custom action when its being marked unstable and hook up the TSC unstable code. Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/mutex: Initialize mutex_waiter::ww_ctx with poison when debuggingNicolai Hähnle
Help catch cases where mutex_lock is used directly on w/w mutexes, which otherwise result in the w/w tasks reading uninitialized data. Signed-off-by: Nicolai Hähnle <Nicolai.Haehnle@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <dev@mblankhorst.nl> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dri-devel@lists.freedesktop.org Link: http://lkml.kernel.org/r/1482346000-9927-12-git-send-email-nhaehnle@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/ww_mutex: Add waiters in stamp orderNicolai Hähnle
Add regular waiters in stamp order. Keep adding waiters that have no context in FIFO order and take care not to starve them. While adding our task as a waiter, back off if we detect that there is a waiter with a lower stamp in front of us. Make sure to call lock_contended even when we back off early. For w/w mutexes, being first in the wait list is only stable when taking the lock without a context. Therefore, the purpose of the first flag is split into two: 'first' remains to indicate whether we want to spin optimistically, while 'handoff' indicates that we should be prepared to accept a handoff. For w/w locking with a context, we always accept handoffs after the first schedule(), to handle the following sequence of events: 1. Task #0 unlocks and hands off to Task #2 which is first in line 2. Task #1 adds itself in front of Task #2 3. Task #2 wakes up and must accept the handoff even though it is no longer first in line Signed-off-by: Nicolai Hähnle <nicolai.haehnle@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: =?UTF-8?q?Nicolai=20H=C3=A4hnle?= <Nicolai.Haehnle@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <dev@mblankhorst.nl> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dri-devel@lists.freedesktop.org Link: http://lkml.kernel.org/r/1482346000-9927-7-git-send-email-nhaehnle@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/ww_mutex: Remove the __ww_mutex_lock*() inline wrappersNicolai Hähnle
Keep the documentation in the header file since there is no good place for it in mutex.c: there are two rather different implementations with different EXPORT_SYMBOLs for each function. Signed-off-by: Nicolai Hähnle <nicolai.haehnle@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: =?UTF-8?q?Nicolai=20H=C3=A4hnle?= <Nicolai.Haehnle@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <dev@mblankhorst.nl> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dri-devel@lists.freedesktop.org Link: http://lkml.kernel.org/r/1482346000-9927-6-git-send-email-nhaehnle@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/ww_mutex: Set use_ww_ctx even when locking without a contextNicolai Hähnle
We will add a new field to struct mutex_waiter. This field must be initialized for all waiters if any waiter uses the ww_use_ctx path. So there is a trade-off: Keep ww_mutex locking without a context on the faster non-use_ww_ctx path, at the cost of adding the initialization to all mutex locks (including non-ww_mutexes), or avoid the additional cost for non-ww_mutex locks, at the cost of adding additional checks to the use_ww_ctx path. We take the latter choice. It may be worth eliminating the users of ww_mutex_lock(lock, NULL), but there are a lot of them. Signed-off-by: Nicolai Hähnle <Nicolai.Haehnle@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <dev@mblankhorst.nl> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dri-devel@lists.freedesktop.org Link: http://lkml.kernel.org/r/1482346000-9927-5-git-send-email-nhaehnle@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/mutex: Fix mutex handoffPeter Zijlstra
While reviewing the ww_mutex patches, I noticed that it was still possible to (incorrectly) succeed for (incorrect) code like: mutex_lock(&a); mutex_lock(&a); This was possible if the second mutex_lock() would block (as expected) but then receive a spurious wakeup. At that point it would find itself at the front of the queue, request a handoff and instantly claim ownership and continue, since owner would point to itself. Avoid this scenario and simplify the code by introducing a third low bit to signal handoff pickup. So once we request handoff, unlock clears the handoff bit and sets the pickup bit along with the new owner. This also removes the need for the .handoff argument to __mutex_trylock(), since that becomes superfluous with PICKUP. In order to guarantee enough low bits, ensure task_struct alignment is at least L1_CACHE_BYTES (which seems a good ideal regardless). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 9d659ae14b54 ("locking/mutex: Add lock handoff to avoid starvation") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14locking/percpu-rwsem: Replace waitqueue with rcuwaitDavidlohr Bueso
The use of any kind of wait queue is an overkill for pcpu-rwsems. While one option would be to use the less heavy simple (swait) flavor, this is still too much for what pcpu-rwsems needs. For one, we do not care about any sort of queuing in that the only (rare) time writers (and readers, for that matter) are queued is when trying to acquire the regular contended rw_sem. There cannot be any further queuing as writers are serialized by the rw_sem in the first place. Given that percpu_down_write() must not be called after exit_notify(), we can replace the bulky waitqueue with rcuwait such that a writer can wait for its turn to take the lock. As such, we can avoid the queue handling and locking overhead. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Link: http://lkml.kernel.org/r/1484148146-14210-3-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14sched/wait, RCU: Introduce rcuwait machineryDavidlohr Bueso
rcuwait provides support for (single) RCU-safe task wait/wake functionality, with the caveat that it must not be called after exit_notify(), such that we avoid racing with rcu delayed_put_task_struct callbacks, task_struct being rcu unaware in this context -- for which we similarly have task_rcu_dereference() magic, but with different return semantics, which can conflict with the wakeup side. The interfaces are quite straightforward: rcuwait_wait_event() rcuwait_wake_up() More details are in the comments, but it's perhaps worth mentioning at least, that users must provide proper serialization when waiting on a condition, and avoid corrupting a concurrent waiter. Also care must be taken between the task and the condition for when calling the wakeup -- we cannot miss wakeups. When porting users, this is for example, a given when using waitqueues in that everything is done under the q->lock. As such, it can remove sources of non preemptable unbounded work for realtime. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Link: http://lkml.kernel.org/r/1484148146-14210-2-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14sched/core: Remove set_task_state()Davidlohr Bueso
This is a nasty interface and setting the state of a foreign task must not be done. As of the following commit: be628be0956 ("bcache: Make gc wakeup sane, remove set_task_state()") ... everyone in the kernel calls set_task_state() with current, allowing the helper to be removed. However, as the comment indicates, it is still around for those archs where computing current is more expensive than using a pointer, at least in theory. An important arch that is affected is arm64, however this has been addressed now [1] and performance is up to par making no difference with either calls. Of all the callers, if any, it's the locking bits that would care most about this -- ie: we end up passing a tsk pointer to a lot of the lock slowpath, and setting ->state on that. The following numbers are based on two tests: a custom ad-hoc microbenchmark that just measures latencies (for ~65 million calls) between get_task_state() vs get_current_state(). Secondly for a higher overview, an unlink microbenchmark was used, which pounds on a single file with open, close,unlink combos with increasing thread counts (up to 4x ncpus). While the workload is quite unrealistic, it does contend a lot on the inode mutex or now rwsem. [1] https://lkml.kernel.org/r/1483468021-8237-1-git-send-email-mark.rutland@arm.com == 1. x86-64 == Avg runtime set_task_state(): 601 msecs Avg runtime set_current_state(): 552 msecs vanilla dirty Hmean unlink1-processes-2 36089.26 ( 0.00%) 38977.33 ( 8.00%) Hmean unlink1-processes-5 28555.01 ( 0.00%) 29832.55 ( 4.28%) Hmean unlink1-processes-8 37323.75 ( 0.00%) 44974.57 ( 20.50%) Hmean unlink1-processes-12 43571.88 ( 0.00%) 44283.01 ( 1.63%) Hmean unlink1-processes-21 34431.52 ( 0.00%) 38284.45 ( 11.19%) Hmean unlink1-processes-30 34813.26 ( 0.00%) 37975.17 ( 9.08%) Hmean unlink1-processes-48 37048.90 ( 0.00%) 39862.78 ( 7.59%) Hmean unlink1-processes-79 35630.01 ( 0.00%) 36855.30 ( 3.44%) Hmean unlink1-processes-110 36115.85 ( 0.00%) 39843.91 ( 10.32%) Hmean unlink1-processes-141 32546.96 ( 0.00%) 35418.52 ( 8.82%) Hmean unlink1-processes-172 34674.79 ( 0.00%) 36899.21 ( 6.42%) Hmean unlink1-processes-203 37303.11 ( 0.00%) 36393.04 ( -2.44%) Hmean unlink1-processes-224 35712.13 ( 0.00%) 36685.96 ( 2.73%) == 2. ppc64le == Avg runtime set_task_state(): 938 msecs Avg runtime set_current_state: 940 msecs vanilla dirty Hmean unlink1-processes-2 19269.19 ( 0.00%) 30704.50 ( 59.35%) Hmean unlink1-processes-5 20106.15 ( 0.00%) 21804.15 ( 8.45%) Hmean unlink1-processes-8 17496.97 ( 0.00%) 17243.28 ( -1.45%) Hmean unlink1-processes-12 14224.15 ( 0.00%) 17240.21 ( 21.20%) Hmean unlink1-processes-21 14155.66 ( 0.00%) 15681.23 ( 10.78%) Hmean unlink1-processes-30 14450.70 ( 0.00%) 15995.83 ( 10.69%) Hmean unlink1-processes-48 16945.57 ( 0.00%) 16370.42 ( -3.39%) Hmean unlink1-processes-79 15788.39 ( 0.00%) 14639.27 ( -7.28%) Hmean unlink1-processes-110 14268.48 ( 0.00%) 14377.40 ( 0.76%) Hmean unlink1-processes-141 14023.65 ( 0.00%) 16271.69 ( 16.03%) Hmean unlink1-processes-172 13417.62 ( 0.00%) 16067.55 ( 19.75%) Hmean unlink1-processes-203 15293.08 ( 0.00%) 15440.40 ( 0.96%) Hmean unlink1-processes-234 13719.32 ( 0.00%) 16190.74 ( 18.01%) Hmean unlink1-processes-265 16400.97 ( 0.00%) 16115.22 ( -1.74%) Hmean unlink1-processes-296 14388.60 ( 0.00%) 16216.13 ( 12.70%) Hmean unlink1-processes-320 15771.85 ( 0.00%) 15905.96 ( 0.85%) x86-64 (known to be fast for get_current()/this_cpu_read_stable() caching) and ppc64 (with paca) show similar improvements in the unlink microbenches. The small delta for ppc64 (2ms), does not represent the gains on the unlink runs. In the case of x86, there was a decent amount of variation in the latency runs, but always within a 20 to 50ms increase), ppc was more constant. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Cc: mark.rutland@arm.com Link: http://lkml.kernel.org/r/1483479794-14013-5-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14perf/x86/intel: Account interrupts for PEBS errorsJiri Olsa
It's possible to set up PEBS events to get only errors and not any data, like on SNB-X (model 45) and IVB-EP (model 62) via 2 perf commands running simultaneously: taskset -c 1 ./perf record -c 4 -e branches:pp -j any -C 10 This leads to a soft lock up, because the error path of the intel_pmu_drain_pebs_nhm() does not account event->hw.interrupt for error PEBS interrupts, so in case you're getting ONLY errors you don't have a way to stop the event when it's over the max_samples_per_tick limit: NMI watchdog: BUG: soft lockup - CPU#22 stuck for 22s! [perf_fuzzer:5816] ... RIP: 0010:[<ffffffff81159232>] [<ffffffff81159232>] smp_call_function_single+0xe2/0x140 ... Call Trace: ? trace_hardirqs_on_caller+0xf5/0x1b0 ? perf_cgroup_attach+0x70/0x70 perf_install_in_context+0x199/0x1b0 ? ctx_resched+0x90/0x90 SYSC_perf_event_open+0x641/0xf90 SyS_perf_event_open+0x9/0x10 do_syscall_64+0x6c/0x1f0 entry_SYSCALL64_slow_path+0x25/0x25 Add perf_event_account_interrupt() which does the interrupt and frequency checks and call it from intel_pmu_drain_pebs_nhm()'s error path. We keep the pending_kill and pending_wakeup logic only in the __perf_event_overflow() path, because they make sense only if there's any data to deliver. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vince@deater.net> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1482931866-6018-2-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14sched/cputime: Rename vtime_account_user() to vtime_flush()Frederic Weisbecker
CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y used to accumulate user time and account it on ticks and context switches only through the vtime_account_user() function. Now this model has been generalized on the 3 archs for all kind of cputime (system, irq, ...) and all the cputime flushing happens under vtime_account_user(). So let's rename this function to better reflect its new role. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-11-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14sched/cputime: Export account_guest_time()Frederic Weisbecker
In order to prepare for CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y to delay cputime accounting to the tick, let's allow archs to account cputime directly to gtime. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-5-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>