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2017-09-07Merge branch 'pci/host-armada' into nextBjorn Helgaas
* pci/host-armada: PCI: armada8k: Fix platform_get_irq() error handling PCI: armada8k: Check the return value from clk_prepare_enable()
2017-09-07Merge branch 'pci/host-altera' into nextBjorn Helgaas
* pci/host-altera: PCI: altera: Fix platform_get_irq() error handling PCI: altera: Use size=4 IRQ domain for legacy INTx PCI: altera: Remove unused num_of_vectors variable
2017-09-07Merge branch 'pci/host-aardvark' into nextBjorn Helgaas
* pci/host-aardvark: PCI: aardvark: Use PCI_NUM_INTX
2017-09-07Merge branch 'pci/irq-intx' into nextBjorn Helgaas
* pci/irq-intx: PCI: Add pci_irqd_intx_xlate() PCI: Move enum pci_interrupt_pin to linux/pci.h
2017-09-07Merge tag 'for-linus-4.14b-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: - the new pvcalls backend for routing socket calls from a guest to dom0 - some cleanups of Xen code - a fix for wrong usage of {get,put}_cpu() * tag 'for-linus-4.14b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (27 commits) xen/mmu: set MMU_NORMAL_PT_UPDATE in remap_area_mfn_pte_fn xen: Don't try to call xen_alloc_p2m_entry() on autotranslating guests xen/events: events_fifo: Don't use {get,put}_cpu() in xen_evtchn_fifo_init() xen/pvcalls: use WARN_ON(1) instead of __WARN() xen: remove not used trace functions xen: remove unused function xen_set_domain_pte() xen: remove tests for pvh mode in pure pv paths xen-platform: constify pci_device_id. xen: cleanup xen.h xen: introduce a Kconfig option to enable the pvcalls backend xen/pvcalls: implement write xen/pvcalls: implement read xen/pvcalls: implement the ioworker functions xen/pvcalls: disconnect and module_exit xen/pvcalls: implement release command xen/pvcalls: implement poll command xen/pvcalls: implement accept command xen/pvcalls: implement listen command xen/pvcalls: implement bind command xen/pvcalls: implement connect command ...
2017-09-07Merge tag 'powerpc-4.14-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Nothing really major this release, despite quite a lot of activity. Just lots of things all over the place. Some things of note include: - Access via perf to a new type of PMU (IMC) on Power9, which can count both core events as well as nest unit events (Memory controller etc). - Optimisations to the radix MMU TLB flushing, mostly to avoid unnecessary Page Walk Cache (PWC) flushes when the structure of the tree is not changing. - Reworks/cleanups of do_page_fault() to modernise it and bring it closer to other architectures where possible. - Rework of our page table walking so that THP updates only need to send IPIs to CPUs where the affected mm has run, rather than all CPUs. - The size of our vmalloc area is increased to 56T on 64-bit hash MMU systems. This avoids problems with the percpu allocator on systems with very sparse NUMA layouts. - STRICT_KERNEL_RWX support on PPC32. - A new sched domain topology for Power9, to capture the fact that pairs of cores may share an L2 cache. - Power9 support for VAS, which is a new mechanism for accessing coprocessors, and initial support for using it with the NX compression accelerator. - Major work on the instruction emulation support, adding support for many new instructions, and reworking it so it can be used to implement the emulation needed to fixup alignment faults. - Support for guests under PowerVM to use the Power9 XIVE interrupt controller. And probably that many things again that are almost as interesting, but I had to keep the list short. Plus the usual fixes and cleanups as always. Thanks to: Alexey Kardashevskiy, Alistair Popple, Andreas Schwab, Aneesh Kumar K.V, Anju T Sudhakar, Arvind Yadav, Balbir Singh, Benjamin Herrenschmidt, Bhumika Goyal, Breno Leitao, Bryant G. Ly, Christophe Leroy, Cédric Le Goater, Dan Carpenter, Dou Liyang, Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff Levand, Hannes Reinecke, Haren Myneni, Ivan Mikhaylov, John Allen, Julia Lawall, LABBE Corentin, Laurentiu Tudor, Madhavan Srinivasan, Markus Elfring, Masahiro Yamada, Matt Brown, Michael Neuling, Murilo Opsfelder Araujo, Nathan Fontenot, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Rashmica Gupta, Rob Herring, Rui Teng, Sam Bobroff, Santosh Sivaraj, Scott Wood, Shilpasri G Bhat, Sukadev Bhattiprolu, Suraj Jitindar Singh, Tobin C. Harding, Victor Aoqui" * tag 'powerpc-4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (321 commits) powerpc/xive: Fix section __init warning powerpc: Fix kernel crash in emulation of vector loads and stores powerpc/xive: improve debugging macros powerpc/xive: add XIVE Exploitation Mode to CAS powerpc/xive: introduce H_INT_ESB hcall powerpc/xive: add the HW IRQ number under xive_irq_data powerpc/xive: introduce xive_esb_write() powerpc/xive: rename xive_poke_esb() in xive_esb_read() powerpc/xive: guest exploitation of the XIVE interrupt controller powerpc/xive: introduce a common routine xive_queue_page_alloc() powerpc/sstep: Avoid used uninitialized error axonram: Return directly after a failed kzalloc() in axon_ram_probe() axonram: Improve a size determination in axon_ram_probe() axonram: Delete an error message for a failed memory allocation in axon_ram_probe() powerpc/powernv/npu: Move tlb flush before launching ATSD powerpc/macintosh: constify wf_sensor_ops structures powerpc/iommu: Use permission-specific DEVICE_ATTR variants powerpc/eeh: Delete an error out of memory message at init time powerpc/mm: Use seq_putc() in two functions macintosh: Convert to using %pOF instead of full_name ...
2017-09-07Merge branch 'efi-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Ingo Molnar: "The main changes in this cycle were: - Transparently fall back to other poweroff method(s) if EFI poweroff fails (and returns) - Use separate PE/COFF section headers for the RX and RW parts of the ARM stub loader so that the firmware can use strict mapping permissions - Add support for requesting the firmware to wipe RAM at warm reboot - Increase the size of the random seed obtained from UEFI so CRNG fast init can complete earlier - Update the EFI framebuffer address if it points to a BAR that gets moved by the PCI resource allocation code - Enable "reset attack mitigation" of TPM environments: this is enabled if the kernel is configured with CONFIG_RESET_ATTACK_MITIGATION=y. - Clang related fixes - Misc cleanups, constification, refactoring, etc" * 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi/bgrt: Use efi_mem_type() efi: Move efi_mem_type() to common code efi/reboot: Make function pointer orig_pm_power_off static efi/random: Increase size of firmware supplied randomness efi/libstub: Enable reset attack mitigation firmware/efi/esrt: Constify attribute_group structures firmware/efi: Constify attribute_group structures firmware/dcdbas: Constify attribute_group structures arm/efi: Split zImage code and data into separate PE/COFF sections arm/efi: Replace open coded constants with symbolic ones arm/efi: Remove pointless dummy .reloc section arm/efi: Remove forbidden values from the PE/COFF header drivers/fbdev/efifb: Allow BAR to be moved instead of claiming it efi/reboot: Fall back to original power-off method if EFI_RESET_SHUTDOWN returns efi/arm/arm64: Add missing assignment of efi.config_table efi/libstub/arm64: Set -fpie when building the EFI stub efi/libstub/arm64: Force 'hidden' visibility for section markers efi/libstub/arm64: Use hidden attribute for struct screen_info reference efi/arm: Don't mark ACPI reclaim memory as MEMBLOCK_NOMAP
2017-09-07Merge tag 'mac80211-for-davem-2017-09-07' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211 Johannes Berg says: ==================== Back from a long absence, so we have a number of things: * a remain-on-channel fix from Avi * hwsim TX power fix from Beni * null-PTR dereference with iTXQ in some rare configurations (Chunho) * 40 MHz custom regdomain fixes (Emmanuel) * look at right place in HT/VHT capability parsing (Igor) * complete A-MPDU teardown properly (Ilan) * Mesh ID Element ordering fix (Liad) * avoid tracing warning in ht_dbg() (Sharon) * fix print of assoc/reassoc (Simon) * fix encrypted VLAN with iTXQ (myself) * fix calling context of TX queue wake (myself) * fix a deadlock with ath10k aggregation (myself) ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-07iwlwifi: mvm: only send LEDS_CMD when the FW supports itLuca Coelho
The LEDS_CMD command is only supported in some newer FW versions (e.g. iwlwifi-8000C-31.ucode), so we can't send it to older versions (such as iwlwifi-8000C-27.ucode). To fix this, check for a new bit in the FW capabilities TLV that tells when the command is supported. Note that the current version of -31.ucode in linux-firmware.git (31.532993.0) does not have this capability bit set, so the LED won't work, even though this version should support it. But we will update this firmware soon, so it won't be a problem anymore. Fixes: 7089ae634c50 ("iwlwifi: mvm: use firmware LED command where applicable") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
2017-09-07Merge branch 'kvm-ppc-next' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc KVM/PPC update for 4.14 There are various minor fixes and cleanups. The only new feature is that we now export information about storage key support to userspace, so it can advertise it to the guest. I have pulled in Michael Ellerman's topic/ppc-kvm branch from the powerpc tree to get a couple of fixes that touch both KVM PPC code and other PPC code. That's why there is some arch/powerpc stuff in the diffstat that isn't arch/powerpc/kvm.
2017-09-07fs: aio: fix the increment of aio-nr and counting against aio-max-nrMauricio Faria de Oliveira
Currently, aio-nr is incremented in steps of 'num_possible_cpus() * 8' for io_setup(nr_events, ..) with 'nr_events < num_possible_cpus() * 4': ioctx_alloc() ... nr_events = max(nr_events, num_possible_cpus() * 4); nr_events *= 2; ... ctx->max_reqs = nr_events; ... aio_nr += ctx->max_reqs; .... This limits the number of aio contexts actually available to much less than aio-max-nr, and is increasingly worse with greater number of CPUs. For example, with 64 CPUs, only 256 aio contexts are actually available (with aio-max-nr = 65536) because the increment is 512 in that scenario. Note: 65536 [max aio contexts] / (64*4*2) [increment per aio context] is 128, but make it 256 (double) as counting against 'aio-max-nr * 2': ioctx_alloc() ... if (aio_nr + nr_events > (aio_max_nr * 2UL) || ... goto err_ctx; ... This patch uses the original value of nr_events (from userspace) to increment aio-nr and count against aio-max-nr, which resolves those. Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Reported-by: Lekshmi C. Pillai <lekshmi.cpillai@in.ibm.com> Tested-by: Lekshmi C. Pillai <lekshmi.cpillai@in.ibm.com> Tested-by: Paul Nguyen <nguyenp@us.ibm.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
2017-09-07Merge branch 'x86-platform-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 platform updates from Ingo Molnar: "The main changes include various Hyper-V optimizations such as faster hypercalls and faster/better TLB flushes - and there's also some Intel-MID cleanups" * 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tracing/hyper-v: Trace hyperv_mmu_flush_tlb_others() x86/hyper-v: Support extended CPU ranges for TLB flush hypercalls x86/platform/intel-mid: Make several arrays static, to make code smaller MAINTAINERS: Add missed file for Hyper-V x86/hyper-v: Use hypercall for remote TLB flush hyper-v: Globalize vp_index x86/hyper-v: Implement rep hypercalls hyper-v: Use fast hypercall for HVCALL_SIGNAL_EVENT x86/hyper-v: Introduce fast hypercall implementation x86/hyper-v: Make hv_do_hypercall() inline x86/hyper-v: Include hyperv/ only when CONFIG_HYPERV is set x86/platform/intel-mid: Make 'bt_sfi_data' const x86/platform/intel-mid: Make IRQ allocation a bit more flexible x86/platform/intel-mid: Group timers callbacks together
2017-09-07Merge tag 'kvm-arm-for-v4.14' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm KVM/ARM Changes for v4.14 Two minor cleanups and improvements, a fix for decoding external abort types from guests, and added support for migrating the active priority of interrupts when running a GICv2 guest on a GICv3 host.
2017-09-07NFS: Sync the correct byte range during synchronous writestarangg@amazon.com
Since commit 18290650b1c8 ("NFS: Move buffered I/O locking into nfs_file_write()") nfs_file_write() has not flushed the correct byte range during synchronous writes. generic_write_sync() expects that iocb->ki_pos points to the right edge of the range rather than the left edge. To replicate the problem, open a file with O_DSYNC, have the client write at increasing offsets, and then print the successful offsets. Block port 2049 partway through that sequence, and observe that the client application indicates successful writes in advance of what the server received. Fixes: 18290650b1c8 ("NFS: Move buffered I/O locking into nfs_file_write()") Signed-off-by: Jacob Strauss <jsstraus@amazon.com> Signed-off-by: Tarang Gupta <tarangg@amazon.com> Tested-by: Tarang Gupta <tarangg@amazon.com> Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-07Merge tag 'kvm-s390-next-4.14-2' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux KVM: s390: Fixes and features for 4.14 - merge of topic branch tlb-flushing from the s390 tree to get the no-dat base features - merge of kvm/master to avoid conflicts with additional sthyi fixes - wire up the no-dat enhancements in KVM - multiple epoch facility (z14 feature) - Configuration z/Architecture Mode - more sthyi fixes - gdb server range checking fix - small code cleanups
2017-09-07PCI: xgene: Clean up whitespaceBjorn Helgaas
Use tabs (not spaces) for indentation. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-09-07PCI: xgene: Define XGENE_PCI_EXP_CAP and use generic PCI_EXP_RTCTL offsetBjorn Helgaas
Apparently the PCIe capability is at address 0x40 in config space of X-Gene v1 Root Ports. Add a definition of that and use the generic PCI_EXP_RTCTL offset into the capability. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-09-07PCI: xgene: Fix platform_get_irq() error handlingFabio Estevam
When platform_get_irq() fails we should propagate the real error value instead of always returning -EINVAL. Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Duc Dang <dhdang@apm.com>
2017-09-07rtlwifi: btcoexist: Fix antenna selection codeLarry Finger
In commit 87d8a9f35202 ("rtlwifi: btcoex: call bind to setup btcoex"), the code turns on a call to exhalbtc_bind_bt_coex_withadapter(). This routine contains a bug that causes incorrect antenna selection for those HP laptops with only one antenna and an incorrectly programmed EFUSE. These boxes are the ones that need the ant_sel module parameter. Fixes: 87d8a9f35202 ("rtlwifi: btcoex: call bind to setup btcoex") Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Ping-Ke Shih <pkshih@realtek.com> Cc: Yan-Hsuan Chuang <yhchuang@realtek.com> Cc: Birming Chiu <birming@realtek.com> Cc: Shaofu <shaofu@realtek.com> Cc: Steven Ting <steventing@realtek.com> Cc: Stable <stable@vger.kernel.org> # 4.13+ Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
2017-09-07rtlwifi: btcoexist: Fix breakage of ant_sel for rtl8723beLarry Finger
In commit bcd37f4a0831 ("rtlwifi: btcoex: 23b 2ant: let bt transmit when hw initialisation done"), there is an additional error when the module parameter ant_sel is used to select the auxilary antenna. The error is that the antenna selection is not checked when writing the antenna selection register. Fixes: bcd37f4a0831 ("rtlwifi: btcoex: 23b 2ant: let bt transmit when hw initialisation done") Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Ping-Ke Shih <pkshih@realtek.com> Cc: Yan-Hsuan Chuang <yhchuang@realtek.com> Cc: Birming Chiu <birming@realtek.com> Cc: Shaofu <shaofu@realtek.com> Cc: Steven Ting <steventing@realtek.com> Cc: Stable <stable@vger.kernel.org> # 4.12+ Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
2017-09-07x86/mm: Make the SME mask a u64Borislav Petkov
The SME encryption mask is for masking 64-bit pagetable entries. It being an unsigned long works fine on X86_64 but on 32-bit builds in truncates bits leading to Xen guests crashing very early. And regardless, the whole SME mask handling shouldnt've leaked into 32-bit because SME is X86_64-only feature. So, first make the mask u64. And then, add trivial 32-bit versions of the __sme_* macros so that nothing happens there. Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Tested-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Tom Lendacky <Thomas.Lendacky@amd.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas <Thomas.Lendacky@amd.com> Fixes: 21729f81ce8a ("x86/mm: Provide general kernel support for memory encryption") Link: http://lkml.kernel.org/r/20170907093837.76zojtkgebwtqc74@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-07sched/cpuset/pm: Fix cpuset vs. suspend-resume bugsPeter Zijlstra
Cpusets vs. suspend-resume is _completely_ broken. And it got noticed because it now resulted in non-cpuset usage breaking too. On suspend cpuset_cpu_inactive() doesn't call into cpuset_update_active_cpus() because it doesn't want to move tasks about, there is no need, all tasks are frozen and won't run again until after we've resumed everything. But this means that when we finally do call into cpuset_update_active_cpus() after resuming the last frozen cpu in cpuset_cpu_active(), the top_cpuset will not have any difference with the cpu_active_mask and this it will not in fact do _anything_. So the cpuset configuration will not be restored. This was largely hidden because we would unconditionally create identity domains and mobile users would not in fact use cpusets much. And servers what do use cpusets tend to not suspend-resume much. An addition problem is that we'd not in fact wait for the cpuset work to finish before resuming the tasks, allowing spurious migrations outside of the specified domains. Fix the rebuild by introducing cpuset_force_rebuild() and fix the ordering with cpuset_wait_for_hotplug(). Reported-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: deb7aa308ea2 ("cpuset: reorganize CPU / memory hotplug handling") Link: http://lkml.kernel.org/r/20170907091338.orwxrqkbfkki3c24@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-07ALSA: asihpi: Kill BUG_ON() usagesTakashi Iwai
BUG_ON() is the worst choice for a trivial sanity check. Either it should be removed or replaced with a softer one like WARN_ON() if still really needed. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-07ALSA: core: Use %pS printk format for direct addressesHelge Deller
The debug functions uses wrongly the %pF instead of the %pS printk format specifier for printing symbols for the address returned by _builtin_return_address(0). Fix it for the ia64, ppc64 and parisc64 architectures. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-07ALSA: ymfpci: Use common error handling code in snd_ymfpci_create()Markus Elfring
* Add a jump target so that a bit of exception handling can be better reused at the end of this function. This issue was detected by using the Coccinelle software. * The script "checkpatch.pl" pointed information out like the following. ERROR: do not use assignment in if condition Thus fix a few source code places. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-07ALSA: ymfpci: Use common error handling code in snd_card_ymfpci_probe()Markus Elfring
* Add a jump target so that a bit of exception handling can be better reused at the end of this function. This issue was detected by using the Coccinelle software. * The script "checkpatch.pl" pointed information out like the following. ERROR: do not use assignment in if condition Thus fix a few source code places. [ This also fixed a potential use-after-free at error path of snd_opl3_hwdep_new(), too -- tiwai ] Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-07ALSA: 6fire: Use common error handling code in usb6fire_chip_probe()Markus Elfring
Add a jump target so that a bit of exception handling can be better reused at the end of this function. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-07ALSA: usx2y: Use common error handling code in submit_urbs()Markus Elfring
Add a jump target so that a bit of exception handling can be better reused at the end of this function. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-07ALSA: us122l: Use common error handling code in us122l_create_card()Markus Elfring
Add a jump target so that a bit of exception handling can be better reused at the end of this function. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-07ALSA: hdspm: Use common error handling code in snd_hdspm_probe()Markus Elfring
Add a jump target so that a bit of exception handling can be better reused at the end of this function. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-07ALSA: rme9652: Use common code in hdsp_get_iobox_version()Markus Elfring
Add a jump target so that a bit of common code can be better reused at the end of this function. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-07ALSA: maestro3: Use common error handling code in two functionsMarkus Elfring
Add jump targets so that a bit of exception handling can be better reused at the end of these functions. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-07genirq: Make sparse_irq_lock protect what it should protectThomas Gleixner
for_each_active_irq() iterates the sparse irq allocation bitmap. The caller must hold sparse_irq_lock. Several code pathes expect that an active bit in the sparse bitmap also has a valid interrupt descriptor. Unfortunately that's not true. The (de)allocation is a two step process, which holds the sparse_irq_lock only across the queue/remove from the radix tree and the set/clear in the allocation bitmap. If a iteration locks sparse_irq_lock between the two steps, then it might see an active bit but the corresponding irq descriptor is NULL. If that is dereferenced unconditionally, then the kernel oopses. Of course, all iterator sites could be audited and fixed, but.... There is no reason why the sparse_irq_lock needs to be dropped between the two steps, in fact the code becomes simpler when the mutex is held across both and the semantics become more straight forward, so future problems of missing NULL pointer checks in the iteration are avoided and all existing sites are fixed in one go. Expand the lock held sections so both operations are covered and the bitmap and the radixtree are in sync. Fixes: a05a900a51c7 ("genirq: Make sparse_lock a mutex") Reported-and-tested-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2017-09-07sched/fair: Fix wake_affine_llc() balancing rulesPeter Zijlstra
Chris Wilson reported that the SMT balance rules got the +1 on the wrong side, resulting in a bias towards the current LLC; which the load-balancer would then try and undo. Reported-by: Chris Wilson <chris@chris-wilson.co.uk> Tested-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.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: 90001d67be2f ("sched/fair: Fix wake_affine() for !NUMA_BALANCING") Link: http://lkml.kernel.org/r/20170906105131.gqjmaextmn3u6tj2@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-06Merge branch 'for-4.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata Pull libata updates from Tejun Heo: "Except for the ahci fix that fixes a boot issue, nothing major in this pull request. Some new platform controller support and device specific changes" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata: libata: zpodd: make arrays cdb static, reduces object code size ahci: don't use MSI for devices with the silly Intel NVMe remapping scheme dt-bindings: ata: add DT bindings for MediaTek SATA controller ata: mediatek: add support for MediaTek SATA controller pata_octeon_cf: use of_property_read_{bool|u32}() cs5536: add support for IDE controller variant ata: sata_gemini: Introduce explicit IDE pin control ata: sata_gemini: Retire custom pin control ata: ahci_platform: Add shutdown handler ata: sata_gemini: explicitly request exclusive reset control ata: Drop unnecessary static ata: Convert to using %pOF instead of full_name
2017-09-06Merge branch 'for-4.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Several notable changes this cycle: - Thread mode was merged. This will be used for cgroup2 support for CPU and possibly other controllers. Unfortunately, CPU controller cgroup2 support didn't make this pull request but most contentions have been resolved and the support is likely to be merged before the next merge window. - cgroup.stat now shows the number of descendant cgroups. - cpuset now can enable the easier-to-configure v2 behavior on v1 hierarchy" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits) cpuset: Allow v2 behavior in v1 cgroup cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup cgroup: remove unneeded checks cgroup: misc changes cgroup: short-circuit cset_cgroup_from_root() on the default hierarchy cgroup: re-use the parent pointer in cgroup_destroy_locked() cgroup: add cgroup.stat interface with basic hierarchy stats cgroup: implement hierarchy limits cgroup: keep track of number of descent cgroups cgroup: add comment to cgroup_enable_threaded() cgroup: remove unnecessary empty check when enabling threaded mode cgroup: update debug controller to print out thread mode information cgroup: implement cgroup v2 thread support cgroup: implement CSS_TASK_ITER_THREADED cgroup: introduce cgroup->dom_cgrp and threaded css_set handling cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS cgroup: reorganize cgroup.procs / task write path cgroup: replace css_set walking populated test with testing cgrp->nr_populated_csets cgroup: distinguish local and children populated states cgroup: remove now unused list_head @pending in cgroup_apply_cftypes() ...
2017-09-06Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue updates from Tejun Heo: "Nothing major. I introduced a flag collsion bug during v4.13 cycle which is fixed in this pull request. Fortunately, the flag is for debugging / verification and the bug isn't critical" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Fix flag collision workqueue: Use TASK_IDLE workqueue: fix path to documentation workqueue: doc change for ST behavior on NUMA systems
2017-09-06Merge branch 'for-4.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu Pull percpu updates from Tejun Heo: "A lot of changes for percpu this time around. percpu inherited the same area allocator from the original pre-virtual-address-mapped implementation. This was from the time when percpu allocator wasn't used all that much and the implementation was focused on simplicity, with the unfortunate computational complexity of O(number of areas allocated from the chunk) per alloc / free. With the increase in percpu usage, we're hitting cases where the lack of scalability is hurting. The most prominent one right now is bpf perpcu map creation / destruction which may allocate and free a lot of entries consecutively and it's likely that the problem will become more prominent in the future. To address the issue, Dennis replaced the area allocator with hinted bitmap allocator which is more consistent. While the new allocator does perform a bit worse in some cases, it outperforms the old allocator way more than an order of magnitude in other more common scenarios while staying mostly flat in CPU overhead and completely flat in memory consumption" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (27 commits) percpu: update header to contain bitmap allocator explanation. percpu: update pcpu_find_block_fit to use an iterator percpu: use metadata blocks to update the chunk contig hint percpu: update free path to take advantage of contig hints percpu: update alloc path to only scan if contig hints are broken percpu: keep track of the best offset for contig hints percpu: skip chunks if the alloc does not fit in the contig hint percpu: add first_bit to keep track of the first free in the bitmap percpu: introduce bitmap metadata blocks percpu: replace area map allocator with bitmap percpu: generalize bitmap (un)populated iterators percpu: increase minimum percpu allocation size and align first regions percpu: introduce nr_empty_pop_pages to help empty page accounting percpu: change the number of pages marked in the first_chunk pop bitmap percpu: combine percpu address checks percpu: modify base_addr to be region specific percpu: setup_first_chunk rename schunk/dchunk to chunk percpu: end chunk area maps page aligned for the populated bitmap percpu: unify allocation of schunk and dchunk percpu: setup_first_chunk remove dyn_size and consolidate logic ...
2017-09-06tipc: remove unnecessary call to dev_net()Kleber Sacilotto de Souza
The net device is already stored in the 'net' variable, so no need to call dev_net() again. Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-06netlink: access nlk groups safely in netlink bind and getnameXin Long
Now there is no lock protecting nlk ngroups/groups' accessing in netlink bind and getname. It's safe from nlk groups' setting in netlink_release, but not from netlink_realloc_groups called by netlink_setsockopt. netlink_lock_table is needed in both netlink bind and getname when accessing nlk groups. Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-06netlink: fix an use-after-free issue for nlk groupsXin Long
ChunYu found a netlink use-after-free issue by syzkaller: [28448.842981] BUG: KASAN: use-after-free in __nla_put+0x37/0x40 at addr ffff8807185e2378 [28448.969918] Call Trace: [...] [28449.117207] __nla_put+0x37/0x40 [28449.132027] nla_put+0xf5/0x130 [28449.146261] sk_diag_fill.isra.4.constprop.5+0x5a0/0x750 [netlink_diag] [28449.176608] __netlink_diag_dump+0x25a/0x700 [netlink_diag] [28449.202215] netlink_diag_dump+0x176/0x240 [netlink_diag] [28449.226834] netlink_dump+0x488/0xbb0 [28449.298014] __netlink_dump_start+0x4e8/0x760 [28449.317924] netlink_diag_handler_dump+0x261/0x340 [netlink_diag] [28449.413414] sock_diag_rcv_msg+0x207/0x390 [28449.432409] netlink_rcv_skb+0x149/0x380 [28449.467647] sock_diag_rcv+0x2d/0x40 [28449.484362] netlink_unicast+0x562/0x7b0 [28449.564790] netlink_sendmsg+0xaa8/0xe60 [28449.661510] sock_sendmsg+0xcf/0x110 [28449.865631] __sys_sendmsg+0xf3/0x240 [28450.000964] SyS_sendmsg+0x32/0x50 [28450.016969] do_syscall_64+0x25c/0x6c0 [28450.154439] entry_SYSCALL64_slow_path+0x25/0x25 It was caused by no protection between nlk groups' free in netlink_release and nlk groups' accessing in sk_diag_dump_groups. The similar issue also exists in netlink_seq_show(). This patch is to defer nlk groups' free in deferred_put_nlk_sk. Reported-by: ChunYu Wang <chunwang@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-06sched: Use __qdisc_drop instead of kfree_skb in sch_prio and sch_qfqGao Feng
The commit 520ac30f4551 ("net_sched: drop packets after root qdisc lock is released) made a big change of tc for performance. There are two points left in sch_prio and sch_qfq which are not changed with that commit. Now enhance them now with __qdisc_drop. Signed-off-by: Gao Feng <gfree.wind@vip.163.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-06dt-binding: phy: don't confuse with Ethernet phy propertiesBaruch Siach
The generic PHY 'phys' property sometime appears in the same node with the Ethernet PHY 'phy' or 'phy-handle' properties. Add a warning in phy-bindings.txt to reduce confusion. Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-06Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge updates from Andrew Morton: - various misc bits - DAX updates - OCFS2 - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (119 commits) mm,fork: introduce MADV_WIPEONFORK x86,mpx: make mpx depend on x86-64 to free up VMA flag mm: add /proc/pid/smaps_rollup mm: hugetlb: clear target sub-page last when clearing huge page mm: oom: let oom_reap_task and exit_mmap run concurrently swap: choose swap device according to numa node mm: replace TIF_MEMDIE checks by tsk_is_oom_victim mm, oom: do not rely on TIF_MEMDIE for memory reserves access z3fold: use per-cpu unbuddied lists mm, swap: don't use VMA based swap readahead if HDD is used as swap mm, swap: add sysfs interface for VMA based swap readahead mm, swap: VMA based swap readahead mm, swap: fix swap readahead marking mm, swap: add swap readahead hit statistics mm/vmalloc.c: don't reinvent the wheel but use existing llist API mm/vmstat.c: fix wrong comment selftests/memfd: add memfd_create hugetlbfs selftest mm/shmem: add hugetlbfs support to memfd_create() mm, devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups mm/vmalloc.c: halve the number of comparisons performed in pcpu_get_vm_areas() ...
2017-09-06x86/mm: Document how CR4.PCIDE restore worksAndy Lutomirski
While debugging a problem, I thought that using cr4_set_bits_and_update_boot() to restore CR4.PCIDE would be helpful. It turns out to be counterproductive. Add a comment documenting how this works. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06x86/mm: Reinitialize TLB state on hotplug and resumeAndy Lutomirski
When Linux brings a CPU down and back up, it switches to init_mm and then loads swapper_pg_dir into CR3. With PCID enabled, this has the side effect of masking off the ASID bits in CR3. This can result in some confusion in the TLB handling code. If we bring a CPU down and back up with any ASID other than 0, we end up with the wrong ASID active on the CPU after resume. This could cause our internal state to become corrupt, although major corruption is unlikely because init_mm doesn't have any user pages. More obviously, if CONFIG_DEBUG_VM=y, we'll trip over an assertion in the next context switch. The result of *that* is a failure to resume from suspend with probability 1 - 1/6^(cpus-1). Fix it by reinitializing cpu_tlbstate on resume and CPU bringup. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jiri Kosina <jikos@kernel.org> Fixes: 10af6235e0d3 ("x86/mm: Implement PCID based optimization: try to preserve old TLB entries using PCID") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06tracing: Apply trace_clock changes to instance max bufferBaohong Liu
Currently trace_clock timestamps are applied to both regular and max buffers only for global trace. For instance trace, trace_clock timestamps are applied only to regular buffer. But, regular and max buffers can be swapped, for example, following a snapshot. So, for instance trace, bad timestamps can be seen following a snapshot. Let's apply trace_clock timestamps to instance max buffer as well. Link: http://lkml.kernel.org/r/ebdb168d0be042dcdf51f81e696b17fabe3609c1.1504642143.git.tom.zanussi@linux.intel.com Cc: stable@vger.kernel.org Fixes: 277ba0446 ("tracing: Add interface to allow multiple trace buffers") Signed-off-by: Baohong Liu <baohong.liu@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-09-06mm,fork: introduce MADV_WIPEONFORKRik van Riel
Introduce MADV_WIPEONFORK semantics, which result in a VMA being empty in the child process after fork. This differs from MADV_DONTFORK in one important way. If a child process accesses memory that was MADV_WIPEONFORK, it will get zeroes. The address ranges are still valid, they are just empty. If a child process accesses memory that was MADV_DONTFORK, it will get a segmentation fault, since those address ranges are no longer valid in the child after fork. Since MADV_DONTFORK also seems to be used to allow very large programs to fork in systems with strict memory overcommit restrictions, changing the semantics of MADV_DONTFORK might break existing programs. MADV_WIPEONFORK only works on private, anonymous VMAs. The use case is libraries that store or cache information, and want to know that they need to regenerate it in the child process after fork. Examples of this would be: - systemd/pulseaudio API checks (fail after fork) (replacing a getpid check, which is too slow without a PID cache) - PKCS#11 API reinitialization check (mandated by specification) - glibc's upcoming PRNG (reseed after fork) - OpenSSL PRNG (reseed after fork) The security benefits of a forking server having a re-inialized PRNG in every child process are pretty obvious. However, due to libraries having all kinds of internal state, and programs getting compiled with many different versions of each library, it is unreasonable to expect calling programs to re-initialize everything manually after fork. A further complication is the proliferation of clone flags, programs bypassing glibc's functions to call clone directly, and programs calling unshare, causing the glibc pthread_atfork hook to not get called. It would be better to have the kernel take care of this automatically. The patch also adds MADV_KEEPONFORK, to undo the effects of a prior MADV_WIPEONFORK. This is similar to the OpenBSD minherit syscall with MAP_INHERIT_ZERO: https://man.openbsd.org/minherit.2 [akpm@linux-foundation.org: numerically order arch/parisc/include/uapi/asm/mman.h #defines] Link: http://lkml.kernel.org/r/20170811212829.29186-3-riel@redhat.com Signed-off-by: Rik van Riel <riel@redhat.com> Reported-by: Florian Weimer <fweimer@redhat.com> Reported-by: Colm MacCártaigh <colm@allcosts.net> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06x86,mpx: make mpx depend on x86-64 to free up VMA flagRik van Riel
Patch series "mm,fork,security: introduce MADV_WIPEONFORK", v4. If a child process accesses memory that was MADV_WIPEONFORK, it will get zeroes. The address ranges are still valid, they are just empty. If a child process accesses memory that was MADV_DONTFORK, it will get a segmentation fault, since those address ranges are no longer valid in the child after fork. Since MADV_DONTFORK also seems to be used to allow very large programs to fork in systems with strict memory overcommit restrictions, changing the semantics of MADV_DONTFORK might break existing programs. The use case is libraries that store or cache information, and want to know that they need to regenerate it in the child process after fork. Examples of this would be: - systemd/pulseaudio API checks (fail after fork) (replacing a getpid check, which is too slow without a PID cache) - PKCS#11 API reinitialization check (mandated by specification) - glibc's upcoming PRNG (reseed after fork) - OpenSSL PRNG (reseed after fork) The security benefits of a forking server having a re-inialized PRNG in every child process are pretty obvious. However, due to libraries having all kinds of internal state, and programs getting compiled with many different versions of each library, it is unreasonable to expect calling programs to re-initialize everything manually after fork. A further complication is the proliferation of clone flags, programs bypassing glibc's functions to call clone directly, and programs calling unshare, causing the glibc pthread_atfork hook to not get called. It would be better to have the kernel take care of this automatically. The patchset also adds MADV_KEEPONFORK, to undo the effects of a prior MADV_WIPEONFORK. This is similar to the OpenBSD minherit syscall with MAP_INHERIT_ZERO: https://man.openbsd.org/minherit.2 This patch (of 2): MPX only seems to be available on 64 bit CPUs, starting with Skylake and Goldmont. Move VM_MPX into the 64 bit only portion of vma->vm_flags, in order to free up a VMA flag. Link: http://lkml.kernel.org/r/20170811212829.29186-2-riel@redhat.com Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Florian Weimer <fweimer@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Colm MacCártaigh <colm@allcosts.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06mm: add /proc/pid/smaps_rollupDaniel Colascione
/proc/pid/smaps_rollup is a new proc file that improves the performance of user programs that determine aggregate memory statistics (e.g., total PSS) of a process. Android regularly "samples" the memory usage of various processes in order to balance its memory pool sizes. This sampling process involves opening /proc/pid/smaps and summing certain fields. For very large processes, sampling memory use this way can take several hundred milliseconds, due mostly to the overhead of the seq_printf calls in task_mmu.c. smaps_rollup improves the situation. It contains most of the fields of /proc/pid/smaps, but instead of a set of fields for each VMA, smaps_rollup instead contains one synthetic smaps-format entry representing the whole process. In the single smaps_rollup synthetic entry, each field is the summation of the corresponding field in all of the real-smaps VMAs. Using a common format for smaps_rollup and smaps allows userspace parsers to repurpose parsers meant for use with non-rollup smaps for smaps_rollup, and it allows userspace to switch between smaps_rollup and smaps at runtime (say, based on the availability of smaps_rollup in a given kernel) with minimal fuss. By using smaps_rollup instead of smaps, a caller can avoid the significant overhead of formatting, reading, and parsing each of a large process's potentially very numerous memory mappings. For sampling system_server's PSS in Android, we measured a 12x speedup, representing a savings of several hundred milliseconds. One alternative to a new per-process proc file would have been including PSS information in /proc/pid/status. We considered this option but thought that PSS would be too expensive (by a few orders of magnitude) to collect relative to what's already emitted as part of /proc/pid/status, and slowing every user of /proc/pid/status for the sake of readers that happen to want PSS feels wrong. The code itself works by reusing the existing VMA-walking framework we use for regular smaps generation and keeping the mem_size_stats structure around between VMA walks instead of using a fresh one for each VMA. In this way, summation happens automatically. We let seq_file walk over the VMAs just as it does for regular smaps and just emit nothing to the seq_file until we hit the last VMA. Benchmarks: using smaps: iterations:1000 pid:1163 pss:220023808 0m29.46s real 0m08.28s user 0m20.98s system using smaps_rollup: iterations:1000 pid:1163 pss:220702720 0m04.39s real 0m00.03s user 0m04.31s system We're using the PSS samples we collect asynchronously for system-management tasks like fine-tuning oom_adj_score, memory use tracking for debugging, application-level memory-use attribution, and deciding whether we want to kill large processes during system idle maintenance windows. Android has been using PSS for these purposes for a long time; as the average process VMA count has increased and and devices become more efficiency-conscious, PSS-collection inefficiency has started to matter more. IMHO, it'd be a lot safer to optimize the existing PSS-collection model, which has been fine-tuned over the years, instead of changing the memory tracking approach entirely to work around smaps-generation inefficiency. Tim said: : There are two main reasons why Android gathers PSS information: : : 1. Android devices can show the user the amount of memory used per : application via the settings app. This is a less important use case. : : 2. We log PSS to help identify leaks in applications. We have found : an enormous number of bugs (in the Android platform, in Google's own : apps, and in third-party applications) using this data. : : To do this, system_server (the main process in Android userspace) will : sample the PSS of a process three seconds after it changes state (for : example, app is launched and becomes the foreground application) and about : every ten minutes after that. The net result is that PSS collection is : regularly running on at least one process in the system (usually a few : times a minute while the screen is on, less when screen is off due to : suspend). PSS of a process is an incredibly useful stat to track, and we : aren't going to get rid of it. We've looked at some very hacky approaches : using RSS ("take the RSS of the target process, subtract the RSS of the : zygote process that is the parent of all Android apps") to reduce the : accounting time, but it regularly overestimated the memory used by 20+ : percent. Accordingly, I don't think that there's a good alternative to : using PSS. : : We started looking into PSS collection performance after we noticed random : frequency spikes while a phone's screen was off; occasionally, one of the : CPU clusters would ramp to a high frequency because there was 200-300ms of : constant CPU work from a single thread in the main Android userspace : process. The work causing the spike (which is reasonable governor : behavior given the amount of CPU time needed) was always PSS collection. : As a result, Android is burning more power than we should be on PSS : collection. : : The other issue (and why I'm less sure about improving smaps as a : long-term solution) is that the number of VMAs per process has increased : significantly from release to release. After trying to figure out why we : were seeing these 200-300ms PSS collection times on Android O but had not : noticed it in previous versions, we found that the number of VMAs in the : main system process increased by 50% from Android N to Android O (from : ~1800 to ~2700) and varying increases in every userspace process. Android : M to N also had an increase in the number of VMAs, although not as much. : I'm not sure why this is increasing so much over time, but thinking about : ASLR and ways to make ASLR better, I expect that this will continue to : increase going forward. I would not be surprised if we hit 5000 VMAs on : the main Android process (system_server) by 2020. : : If we assume that the number of VMAs is going to increase over time, then : doing anything we can do to reduce the overhead of each VMA during PSS : collection seems like the right way to go, and that means outputting an : aggregate statistic (to avoid whatever overhead there is per line in : writing smaps and in reading each line from userspace). Link: http://lkml.kernel.org/r/20170812022148.178293-1-dancol@google.com Signed-off-by: Daniel Colascione <dancol@google.com> Cc: Tim Murray <timmurray@google.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sonny Rao <sonnyrao@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>