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2016-09-30rxrpc: Fix the call timer handlingDavid Howells
The call timer's concept of a call timeout (of which there are three) that is inactive is that it is the timeout has the same expiration time as the call expiration timeout (the expiration timer is never inactive). However, I'm not resetting the timeouts when they expire, leading to repeated processing of expired timeouts when other timeout events occur. Fix this by: (1) Move the timer expiry detection into rxrpc_set_timer() inside the locked section. This means that if a timeout is set that will expire immediately, we deal with it immediately. (2) If a timeout is at or before now then it has expired. When an expiry is detected, an event is raised, the timeout is automatically inactivated and the event processor is queued. (3) If a timeout is at or after the expiry timeout then it is inactive. Inactive timeouts do not contribute to the timer setting. (4) The call timer callback can now just call rxrpc_set_timer() to handle things. (5) The call processor work function now checks the event flags rather than checking the timeouts directly. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30rxrpc: Keep the call timeouts as ktimes rather than jiffiesDavid Howells
Keep that call timeouts as ktimes rather than jiffies so that they can be expressed as functions of RTT. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30rxrpc: Remove error from struct rxrpc_skb_priv as it is unusedDavid Howells
Remove error from struct rxrpc_skb_priv as it is no longer used. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30rxrpc: The offset field in struct rxrpc_skb_priv is unnecessaryDavid Howells
The offset field in struct rxrpc_skb_priv is unnecessary as the value can always be calculated. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30rxrpc: Reduce ssthresh to peer's receive windowDavid Howells
When we receive an ACK from the peer that tells us what the peer's receive window (rwind) is, we should reduce ssthresh to rwind if rwind is smaller than ssthresh. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30rxrpc: Switch to Congestion Avoidance mode at cwnd==ssthreshDavid Howells
Switch to Congestion Avoidance mode at cwnd == ssthresh rather than relying on cwnd getting incremented beyond ssthresh and the window size, the mode being shifted and then cwnd being corrected. We need to make sure we switch into CA mode so that we stop marking every packet for ACK. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30mac80211: Move reorder-sensitive TX handlers to after TXQ dequeueToke Høiland-Jørgensen
The TXQ intermediate queues can cause packet reordering when more than one flow is active to a single station. Since some of the wifi-specific packet handling (notably sequence number and encryption handling) is sensitive to re-ordering, things break if they are applied before the TXQ. This splits up the TX handlers and fast_xmit logic into two parts: An early part and a late part. The former is applied before TXQ enqueue, and the latter after dequeue. The non-TXQ path just applies both parts at once. Because fragments shouldn't be split up or reordered, the fragmentation handler is run after dequeue. Any fragments are then kept in the TXQ and on subsequent dequeues they take precedence over dequeueing from the FQ structure. This approach avoids having to scatter special cases all over the place for when TXQ is enabled, at the cost of making the fast_xmit and TX handler code slightly more complex. Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> [fix a few code-style nits, make ieee80211_xmit_fast_finish void, remove a useless txq->sta check] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30x86/entry/64: Fix context tracking state warning when load_gs_index failsWanpeng Li
This warning: WARNING: CPU: 0 PID: 3331 at arch/x86/entry/common.c:45 enter_from_user_mode+0x32/0x50 CPU: 0 PID: 3331 Comm: ldt_gdt_64 Not tainted 4.8.0-rc7+ #13 Call Trace: dump_stack+0x99/0xd0 __warn+0xd1/0xf0 warn_slowpath_null+0x1d/0x20 enter_from_user_mode+0x32/0x50 error_entry+0x6d/0xc0 ? general_protection+0x12/0x30 ? native_load_gs_index+0xd/0x20 ? do_set_thread_area+0x19c/0x1f0 SyS_set_thread_area+0x24/0x30 do_int80_syscall_32+0x7c/0x220 entry_INT80_compat+0x38/0x50 ... can be reproduced by running the GS testcase of the ldt_gdt test unit in the x86 selftests. do_int80_syscall_32() will call enter_form_user_mode() to convert context tracking state from user state to kernel state. The load_gs_index() call can fail with user gsbase, gsbase will be fixed up and proceed if this happen. However, enter_from_user_mode() will be called again in the fixed up path though it is context tracking kernel state currently. This patch fixes it by just fixing up gsbase and telling lockdep that IRQs are off once load_gs_index() failed with user gsbase. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1475197266-3440-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUIDAndy Lutomirski
Otherwise arch_task_struct_size == 0 and we die. While we're at it, set X86_FEATURE_ALWAYS, too. Reported-by: David Saggiorato <david@saggiorato.net> Tested-by: David Saggiorato <david@saggiorato.net> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: aaeb5c01c5b ("x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86") Link: http://lkml.kernel.org/r/8de723afbf0811071185039f9088733188b606c9.1475103911.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30mac80211: mesh: decrease max driftPedersen, Thomas
The old value was 30ms, which means mesh sync will treat any value below as merely TSF drift. This isn't really reasonable (typical drift is < 10us/s) since people probably want to adjust TSF in smaller increments (for ie. beacon collision avoidance) without mesh sync fighting back. Change max drift adjustment to 0.8ms, so manual TSF adjustments can be made in 1ms increments, with some margin. Signed-off-by: Thomas Pedersen <twp@qca.qualcomm.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30mac80211: add offset_tsf driver op and use it for meshPedersen, Thomas
This allows the mesh sync (and debugfs) code to make incremental TSF adjustments, avoiding any uncertainty introduced by delay in programming absolute TSF. Signed-off-by: Thomas Pedersen <twp@qca.qualcomm.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30mac80211: Set lower memory limit for non-VHT devicesToke Høiland-Jørgensen
Small devices can run out of memory from queueing too many packets. If VHT is not supported by the PHY, having more than 4 MBytes of total queue in the TXQ intermediate queues is not needed, and so we can safely limit the memory usage in these cases and avoid OOM. Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30mac80211: Export fq memory limit information in debugfsToke Høiland-Jørgensen
Add memory limit, usage and overlimit counter to per-PHY 'aqm' debugfs file. Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30fq.h: Port memory limit mechanism from fq_codelToke Høiland-Jørgensen
The reusable fairness queueing implementation (fq.h) lacks the memory usage limit that the fq_codel qdisc has. This means that small devices (e.g. WiFi routers) can run out of memory when flooded with a large number of packets. This ports the memory limit feature from fq_codel to fq.h. Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30mac80211: Add API to report NAN function matchAyala Beker
Provide an API to report NAN function match. Mac80211 will lookup the corresponding cookie and report the match to cfg80211. Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30mac80211: Implement add_nan_func and rm_nan_funcAyala Beker
Implement add/rm_nan_func functions and handle NAN function termination notifications. Handle instance_id allocation for NAN functions and implement the reconfig flow. Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30mac80211: implement nan_change_confAyala Beker
Implement nan_change_conf callback which allows to change current NAN configuration (master preference and dual band operation). Store the current NAN configuration in sdata, so it can be used both to provide the driver the updated configuration with changes and also it will be used in hw reconfig flows in next patches. Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30cfg80211: Provide an API to report NAN function terminationAyala Beker
Provide a function that reports NAN DE function termination. The function may be terminated due to one of the following reasons: user request, ttl expiration or failure. If the NAN instance is tied to the owner, the notification will be sent to the socket that started the NAN interface only Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30cfg80211: provide a function to report a match for NANAyala Beker
Provide a function the driver can call to report a match. This will send the event to the user space. If the NAN instance is tied to the owner, the notifications will be sent to the socket that started the NAN interface only. Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30cfg80211: allow the user space to change current NAN configurationAyala Beker
Some NAN configuration paramaters may change during the operation of the NAN device. For example, a user may want to update master preference value when the device gets plugged/unplugged to the power. Add API that allows to do so. Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30cfg80211: add add_nan_func / del_nan_funcAyala Beker
A NAN function can be either publish, subscribe or follow up. Make all the necessary verifications and just pass the request to the driver. Allow the user space application that starts NAN to forbid any other socket to add or remove functions. Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Ayala Beker <ayala.beker@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30mac80211: add boilerplate code for start / stop NANAyala Beker
This code doesn't do much besides allowing to start and stop the vif. Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Ayala Beker <ayala.beker@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30cfg80211: add start / stop NAN commandsAyala Beker
This allows user space to start/stop NAN interface. A NAN interface is like P2P device in a few aspects: it doesn't have a netdev associated to it. Add the new interface type and prevent operations that can't be executed on NAN interface like scan. Define several attributes that may be configured by user space when starting NAN functionality (master preference and dual band operation) Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30cfg80211: Add support for static WEP in the driverDavid Spinadel
Add support for drivers that implement static WEP internally, i.e. expose connection keys to the driver in connect flow and don't upload the keys after the connection. Signed-off-by: David Spinadel <david.spinadel@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30mac80211: Move ieee802111_tx_dequeue() to later in tx.cToke Høiland-Jørgensen
The TXQ path restructure requires ieee80211_tx_dequeue() to call TX handlers and parts of the xmit_fast path. Move the function to later in tx.c in preparation for this. Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-09-30xen/pciback: support driver_overrideJuergen Gross
Support the driver_override scheme introduced with commit 782a985d7af2 ("PCI: Introduce new device binding path using pci_dev.driver_override") As pcistub_probe() is called for all devices (it has to check for a match based on the slot address rather than device type) it has to check for driver_override set to "pciback" itself. Up to now for assigning a pci device to pciback you need something like: echo 0000:07:10.0 > /sys/bus/pci/devices/0000\:07\:10.0/driver/unbind echo 0000:07:10.0 > /sys/bus/pci/drivers/pciback/new_slot echo 0000:07:10.0 > /sys/bus/pci/drivers_probe while with the patch you can use the same mechanism as for similar drivers like pci-stub and vfio-pci: echo pciback > /sys/bus/pci/devices/0000\:07\:10.0/driver_override echo 0000:07:10.0 > /sys/bus/pci/devices/0000\:07\:10.0/driver/unbind echo 0000:07:10.0 > /sys/bus/pci/drivers_probe So e.g. libvirt doesn't need special handling for pciback. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30xen/pciback: avoid multiple entries in slot listJuergen Gross
The Xen pciback driver has a list of all pci devices it is ready to seize. There is no check whether a to be added entry already exists. While this might be no problem in the common case it might confuse those which consume the list via sysfs. Modify the handling of this list by not adding an entry which already exists. As this will be needed later split out the list handling into a separate function. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30xen/pciback: simplify pcistub device handlingJuergen Gross
The Xen pciback driver maintains a list of all its seized devices. There are two functions searching the list for a specific device with basically the same semantics just returning different structures in case of a match. Split out the search function. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30xen: Remove event channel notification through Xen PCI platform deviceKarimAllah Ahmed
Ever since commit 254d1a3f02eb ("xen/pv-on-hvm kexec: shutdown watches from old kernel") using the INTx interrupt from Xen PCI platform device for event channel notification would just lockup the guest during bootup. postcore_initcall now calls xs_reset_watches which will eventually try to read a value from XenStore and will get stuck on read_reply at XenBus forever since the platform driver is not probed yet and its INTx interrupt handler is not registered yet. That means that the guest can not be notified at this moment of any pending event channels and none of the per-event handlers will ever be invoked (including the XenStore one) and the reply will never be picked up by the kernel. The exact stack where things get stuck during xenbus_init: -xenbus_init -xs_init -xs_reset_watches -xenbus_scanf -xenbus_read -xs_single -xs_single -xs_talkv Vector callbacks have always been the favourite event notification mechanism since their introduction in commit 38e20b07efd5 ("x86/xen: event channels delivery on HVM.") and the vector callback feature has always been advertised for quite some time by Xen that's why INTx was broken for several years now without impacting anyone. Luckily this also means that event channel notification through INTx is basically dead-code which can be safely removed without impacting anybody since it has been effectively disabled for more than 4 years with nobody complaining about it (at least as far as I'm aware of). This commit removes event channel notification through Xen PCI platform device. Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Julien Grall <julien.grall@citrix.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Ross Lagerwall <ross.lagerwall@citrix.com> Cc: xen-devel@lists.xenproject.org Cc: linux-kernel@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: Anthony Liguori <aliguori@amazon.com> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30x86/asm: Get rid of __read_cr4_safe()Andy Lutomirski
We use __read_cr4() vs __read_cr4_safe() inconsistently. On CR4-less CPUs, all CR4 bits are effectively clear, so we can make the code simpler and more robust by making __read_cr4() always fix up faults on 32-bit kernels. This may fix some bugs on old 486-like CPUs, but I don't have any easy way to test that. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: david@saggiorato.net Link: http://lkml.kernel.org/r/ea647033d357d9ce2ad2bbde5a631045f5052fb6.1475178370.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-30Merge branch 'x86/urgent' into x86/asmThomas Gleixner
Get the cr4 fixes so we can apply the final cleanup
2016-09-30x86/vdso: Fix building on big endian hostSegher Boessenkool
We need to call GET_LE to read hdr->e_type. Fixes: 57f90c3dfc75 ("x86/vdso: Error out if the vDSO isn't a valid DSO") Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: linux-next@vger.kernel.org Link: http://lkml.kernel.org/r/20160929193442.GA16617@gate.crashing.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-30x86/boot: Fix another __read_cr4() case on 486Andy Lutomirski
The condition for reading CR4 was wrong: there are some CPUs with CPUID but not CR4. Rather than trying to make the condition exact, use __read_cr4_safe(). Fixes: 18bc7bd523e0 ("x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly") Reported-by: david@saggiorato.net Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Link: http://lkml.kernel.org/r/8c453a61c4f44ab6ff43c29780ba04835234d2e5.1475178369.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-30xen/events: Convert to hotplug state machineSebastian Andrzej Siewior
Install the callbacks via the state machine. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30xen/x86: Convert to hotplug state machineBoris Ostrovsky
Switch to new CPU hotplug infrastructure. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30x86/xen: add missing \n at end of printk warning messageColin Ian King
The message is missing a \n, add it. Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30sched/irqtime: Consolidate irqtime flushing codeFrederic Weisbecker
The code performing irqtime nsecs stats flushing to kcpustat is roughly the same for hardirq and softirq. So lets consolidate that common code. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-6-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/irqtime: Consolidate accounting synchronization with u64_stats APIFrederic Weisbecker
The irqtime accounting currently implement its own ad hoc implementation of u64_stats API. Lets rather consolidate it with the appropriate library. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-5-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30u64_stats: Introduce IRQs disabled helpersFrederic Weisbecker
Introduce light versions of u64_stats helpers for context where either preempt or IRQs are disabled. This way we can make this library usable by scheduler irqtime accounting which currenty implement its ad-hoc version. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-4-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/irqtime: Remove needless IRQs disablement on kcpustat updateFrederic Weisbecker
The callers of the functions performing irqtime kcpustat updates have IRQS disabled, no need to disable them again. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-3-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/irqtime: No need for preempt-safe accessorsFrederic Weisbecker
We can safely use the preempt-unsafe accessors for irqtime when we flush its counters to kcpustat as IRQs are disabled at this time. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1474849761-12678-2-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/fair: Fix min_vruntime trackingPeter Zijlstra
While going through enqueue/dequeue to review the movement of set_curr_task() I noticed that the (2nd) update_min_vruntime() call in dequeue_entity() is suspect. It turns out, its actually wrong because it will consider cfs_rq->curr, which could be the entry we just normalized. This mixes different vruntime forms and leads to fail. The purpose of the second update_min_vruntime() is to move min_vruntime forward if the entity we just removed is the one that was holding it back; _except_ for the DEQUEUE_SAVE case, because then we know its a temporary removal and it will come back. However, since we do put_prev_task() _after_ dequeue(), cfs_rq->curr will still be set (and per the above, can be tranformed into a different unit), so update_min_vruntime() should also consider curr->on_rq. This also fixes another corner case where the enqueue (which also does update_curr()->update_min_vruntime()) happens on the rq->lock break in schedule(), between dequeue and put_prev_task. 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 Fixes: 1e876231785d ("sched: Fix ->min_vruntime calculation in dequeue_entity()") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/debug: Add SCHED_WARN_ON()Peter Zijlstra
Provide SCHED_WARN_ON as wrapper for WARN_ON_ONCE() to avoid CONFIG_SCHED_DEBUG wrappery. 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>
2016-09-30sched/core: Fix set_user_nice()Peter Zijlstra
Almost all scheduler functions update state with the following pattern: if (queued) dequeue_task(rq, p, DEQUEUE_SAVE); if (running) put_prev_task(rq, p); /* update state */ if (queued) enqueue_task(rq, p, ENQUEUE_RESTORE); if (running) set_curr_task(rq, p); set_user_nice() however misses the running part, cure this. This was found by asserting we never enqueue 'current'. 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>
2016-09-30sched/fair: Introduce set_curr_task() helperPeter Zijlstra
Now that the ia64 only set_curr_task() symbol is gone, provide a helper just like put_prev_task(). 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>
2016-09-30sched/core, ia64: Rename set_curr_task()Peter Zijlstra
Rename the ia64 only set_curr_task() function to free up the name. 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: Tony Luck <tony.luck@intel.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core: Fix incorrect utilization accounting when switching to fair classVincent Guittot
When a task switches to fair scheduling class, the period between now and the last update of its utilization is accounted as running time whatever happened during this period. This incorrect accounting applies to the task and also to the task group branch. When changing the property of a running task like its list of allowed CPUs or its scheduling class, we follow the sequence: - dequeue task - put task - change the property - set task as current task - enqueue task The end of the sequence doesn't follow the normal sequence (as per __schedule()) which is: - enqueue a task - then set the task as current task. This incorrectordering is the root cause of incorrect utilization accounting. Update the sequence to follow the right one: - dequeue task - put task - change the property - enqueue task - set task as current task Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: dietmar.eggemann@arm.com Cc: linaro-kernel@lists.linaro.org Cc: pjt@google.com Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1473666472-13749-8-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-30sched/core: Optimize SCHED_SMTPeter Zijlstra
Avoid pointless SCHED_SMT code when running on !SMT hardware. 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>
2016-09-30sched/core: Rewrite and improve select_idle_siblings()Peter Zijlstra
select_idle_siblings() is a known pain point for a number of workloads; it either does too much or not enough and sometimes just does plain wrong. This rewrite attempts to address a number of issues (but sadly not all). The current code does an unconditional sched_domain iteration; with the intent of finding an idle core (on SMT hardware). The problems which this patch tries to address are: - its pointless to look for idle cores if the machine is real busy; at which point you're just wasting cycles. - it's behaviour is inconsistent between SMT and !SMT hardware in that !SMT hardware ends up doing a scan for any idle CPU in the LLC domain, while SMT hardware does a scan for idle cores and if that fails, falls back to a scan for idle threads on the 'target' core. The new code replaces the sched_domain scan with 3 explicit scans: 1) search for an idle core in the LLC 2) search for an idle CPU in the LLC 3) search for an idle thread in the 'target' core where 1 and 3 are conditional on SMT support and 1 and 2 have runtime heuristics to skip the step. Step 1) is conditional on sd_llc_shared->has_idle_cores; when a cpu goes idle and sd_llc_shared->has_idle_cores is false, we scan all SMT siblings of the CPU going idle. Similarly, we clear sd_llc_shared->has_idle_cores when we fail to find an idle core. Step 2) tracks the average cost of the scan and compares this to the average idle time guestimate for the CPU doing the wakeup. There is a significant fudge factor involved to deal with the variability of the averages. Esp. hackbench was sensitive to this. Step 3) is unconditional; we assume (also per step 1) that scanning all SMT siblings in a core is 'cheap'. With this; SMT systems gain step 2, which cures a few benchmarks -- notably one from Facebook. One 'feature' of the sched_domain iteration, which we preserve in the new code, is that it would start scanning from the 'target' CPU, instead of scanning the cpumask in cpu id order. This avoids multiple CPUs in the LLC scanning for idle to gang up and find the same CPU quite as much. The down side is that tasks can end up hopping across the LLC for no apparent reason. 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>
2016-09-30x86/cmpxchg, locking/atomics: Remove superfluous definitionsNikolay Borisov
cmpxchg contained definitions for unused (x)add_* operations, dating back to the original ticket spinlock implementation. Nowadays these are unused so remove them. Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com> 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: hpa@zytor.com Link: http://lkml.kernel.org/r/1474913478-17757-1-git-send-email-n.borisov.lkml@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>