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2015-07-04Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Debug info and other statistics fixes and related enhancements" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/numa: Fix numa balancing stats in /proc/pid/sched sched/numa: Show numa_group ID in /proc/sched_debug task listings sched/debug: Move print_cfs_rq() declaration to kernel/sched/sched.h sched/stat: Expose /proc/pid/schedstat if CONFIG_SCHED_INFO=y sched/stat: Simplify the sched_info accounting dependency
2015-07-04Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull max log buf size increase from Ingo Molnar: "Ran into this limit recently, so increase it by an order of magnitude" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: printk: Increase maximum CONFIG_LOG_BUF_SHIFT from 21 to 25
2015-07-04sched/stat: Simplify the sched_info accounting dependencyNaveen N. Rao
Both CONFIG_SCHEDSTATS=y and CONFIG_TASK_DELAY_ACCT=y track task sched_info, which results in ugly #if clauses. Simplify the code by introducing a synthethic CONFIG_SCHED_INFO switch, selected by both. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: a.p.zijlstra@chello.nl Cc: ricklind@us.ibm.com Link: http://lkml.kernel.org/r/8d19eef800811a94b0f91bcbeb27430a884d7433.1435255405.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-01Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Main excitement here is Peter Zijlstra's lockless rbtree optimization to speed module address lookup. He found some abusers of the module lock doing that too. A little bit of parameter work here too; including Dan Streetman's breaking up the big param mutex so writing a parameter can load another module (yeah, really). Unfortunately that broke the usual suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were appended too" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits) modules: only use mod->param_lock if CONFIG_MODULES param: fix module param locks when !CONFIG_SYSFS. rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() module: add per-module param_lock module: make perm const params: suppress unused variable error, warn once just in case code changes. modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. kernel/module.c: avoid ifdefs for sig_enforce declaration kernel/workqueue.c: remove ifdefs over wq_power_efficient kernel/params.c: export param_ops_bool_enable_only kernel/params.c: generalize bool_enable_only kernel/module.c: use generic module param operaters for sig_enforce kernel/params: constify struct kernel_param_ops uses sysfs: tightened sysfs permission checks module: Rework module_addr_{min,max} module: Use __module_address() for module_address_lookup() module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING module: Optimize __module_address() using a latched RB-tree rbtree: Implement generic latch_tree seqlock: Introduce raw_read_seqcount_latch() ...
2015-07-01printk: Increase maximum CONFIG_LOG_BUF_SHIFT from 21 to 25Ingo Molnar
So I tried to some kernel debugging that produced a ton of kernel messages on a big box, and wanted to save them all: but CONFIG_LOG_BUF_SHIFT maxes out at 21 (2 MB). Increase it to 25 (32 MB). This does not affect any existing config or defaults. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> 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>
2015-06-26Merge branch 'for-4.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - threadgroup_lock got reorganized so that its users can pick the actual locking mechanism to use. Its only user - cgroups - is updated to use a percpu_rwsem instead of per-process rwsem. This makes things a bit lighter on hot paths and allows cgroups to perform and fail multi-task (a process) migrations atomically. Multi-task migrations are used in several places including the unified hierarchy. - Delegation rule and documentation added to unified hierarchy. This will likely be the last interface update from the cgroup core side for unified hierarchy before lifting the devel mask. - Some groundwork for the pids controller which is scheduled to be merged in the coming devel cycle. * 'for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: add delegation section to unified hierarchy documentation cgroup: require write perm on common ancestor when moving processes on the default hierarchy cgroup: separate out cgroup_procs_write_permission() from __cgroup_procs_write() kernfs: make kernfs_get_inode() public MAINTAINERS: add a cgroup core co-maintainer cgroup: fix uninitialised iterator in for_each_subsys_which cgroup: replace explicit ss_mask checking with for_each_subsys_which cgroup: use bitmask to filter for_each_subsys cgroup: add seq_file forward declaration for struct cftype cgroup: simplify threadgroup locking sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem sched, cgroup: reorganize threadgroup locking cgroup: switch to unsigned long for bitmasks cgroup: reorganize include/linux/cgroup.h cgroup: separate out include/linux/cgroup-defs.h cgroup: fix some comment typos
2015-06-26Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge second patchbomb from Andrew Morton: - most of the rest of MM - lots of misc things - procfs updates - printk feature work - updates to get_maintainer, MAINTAINERS, checkpatch - lib/ updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits) exit,stats: /* obey this comment */ coredump: add __printf attribute to cn_*printf functions coredump: use from_kuid/kgid when formatting corename fs/reiserfs: remove unneeded cast NILFS2: support NFSv2 export fs/befs/btree.c: remove unneeded initializations fs/minix: remove unneeded cast init/do_mounts.c: add create_dev() failure log kasan: remove duplicate definition of the macro KASAN_FREE_PAGE fs/efs: femove unneeded cast checkpatch: emit "NOTE: <types>" message only once after multiple files checkpatch: emit an error when there's a diff in a changelog checkpatch: validate MODULE_LICENSE content checkpatch: add multi-line handling for PREFER_ETHER_ADDR_COPY checkpatch: suggest using eth_zero_addr() and eth_broadcast_addr() checkpatch: fix processing of MEMSET issues checkpatch: suggest using ether_addr_equal*() checkpatch: avoid NOT_UNIFIED_DIFF errors on cover-letter.patch files checkpatch: remove local from codespell path checkpatch: add --showfile to allow input via pipe to show filenames ...
2015-06-25fs, proc: introduce CONFIG_PROC_CHILDRENIago López Galeiras
Commit 818411616baf ("fs, proc: introduce /proc/<pid>/task/<tid>/children entry") introduced the children entry for checkpoint restore and the file is only available on kernels configured with CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE. This is available in most distributions (Fedora, Debian, Ubuntu, CoreOS) because they usually enable CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE. But Arch does not enable CONFIG_EXPERT or CONFIG_CHECKPOINT_RESTORE. However, the children proc file is useful outside of checkpoint restore. I would like to use it in rkt. The rkt process exec() another program it does not control, and that other program will fork()+exec() a child process. I would like to find the pid of the child process from an external tool without iterating in /proc over all processes to find which one has a parent pid equal to rkt. This commit introduces CONFIG_PROC_CHILDREN and makes CONFIG_CHECKPOINT_RESTORE select it. This allows enabling /proc/<pid>/task/<tid>/children without needing to enable CONFIG_CHECKPOINT_RESTORE and CONFIG_EXPERT. Alban tested that /proc/<pid>/task/<tid>/children is present when the kernel is configured with CONFIG_PROC_CHILDREN=y but without CONFIG_CHECKPOINT_RESTORE Signed-off-by: Iago López Galeiras <iago@endocode.com> Tested-by: Alban Crequy <alban@endocode.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Djalal Harouni <djalal@endocode.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-25Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull cgroup writeback support from Jens Axboe: "This is the big pull request for adding cgroup writeback support. This code has been in development for a long time, and it has been simmering in for-next for a good chunk of this cycle too. This is one of those problems that has been talked about for at least half a decade, finally there's a solution and code to go with it. Also see last weeks writeup on LWN: http://lwn.net/Articles/648292/" * 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits) writeback, blkio: add documentation for cgroup writeback support vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB writeback: do foreign inode detection iff cgroup writeback is enabled v9fs: fix error handling in v9fs_session_init() bdi: fix wrong error return value in cgwb_create() buffer: remove unusued 'ret' variable writeback: disassociate inodes from dying bdi_writebacks writeback: implement foreign cgroup inode bdi_writeback switching writeback: add lockdep annotation to inode_to_wb() writeback: use unlocked_inode_to_wb transaction in inode_congested() writeback: implement unlocked_inode_to_wb transaction and use it for stat updates writeback: implement [locked_]inode_to_wb_and_lock_list() writeback: implement foreign cgroup inode detection writeback: make writeback_control track the inode being written back writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb() mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use writeback: implement memcg writeback domain based throttling writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes writeback: implement memcg wb_domain writeback: update wb_over_bg_thresh() to use wb_domain aware operations ...
2015-06-23modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'.Rusty Russell
Andreas turned this option on, only to find out Debian (and Ubuntu!) don't enable support in their kmod builds. Shorten the text, and suggest N at the bottom (at least for now). Reported-by: Andreas Mohr <andim2@users.sf.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-22Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Kernel side changes mostly consist of work on x86 PMU drivers: - x86 Intel PT (hardware CPU tracer) improvements (Alexander Shishkin) - x86 Intel CQM (cache quality monitoring) improvements (Thomas Gleixner) - x86 Intel PEBSv3 support (Peter Zijlstra) - x86 Intel PEBS interrupt batching support for lower overhead sampling (Zheng Yan, Kan Liang) - x86 PMU scheduler fixes and improvements (Peter Zijlstra) There's too many tooling improvements to list them all - here are a few select highlights: 'perf bench': - Introduce new 'perf bench futex' benchmark: 'wake-parallel', to measure parallel waker threads generating contention for kernel locks (hb->lock). (Davidlohr Bueso) 'perf top', 'perf report': - Allow disabling/enabling events dynamicaly in 'perf top': a 'perf top' session can instantly become a 'perf report' one, i.e. going from dynamic analysis to a static one, returning to a dynamic one is possible, to toogle the modes, just press 'f' to 'freeze/unfreeze' the sampling. (Arnaldo Carvalho de Melo) - Make Ctrl-C stop processing on TUI, allowing interrupting the load of big perf.data files (Namhyung Kim) 'perf probe': (Masami Hiramatsu) - Support glob wildcards for function name - Support $params special probe argument: Collect all function arguments - Make --line checks validate C-style function name. - Add --no-inlines option to avoid searching inline functions - Greatly speed up 'perf probe --list' by caching debuginfo. - Improve --filter support for 'perf probe', allowing using its arguments on other commands, as --add, --del, etc. 'perf sched': - Add option in 'perf sched' to merge like comms to lat output (Josef Bacik) Plus tons of infrastructure work - in particular preparation for upcoming threaded perf report support, but also lots of other work - and fixes and other improvements. See (much) more details in the shortlog and in the git log" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (305 commits) perf tools: Configurable per thread proc map processing time out perf tools: Add time out to force stop proc map processing perf report: Fix sort__sym_cmp to also compare end of symbol perf hists browser: React to unassigned hotkey pressing perf top: Tell the user how to unfreeze events after pressing 'f' perf hists browser: Honour the help line provided by builtin-{top,report}.c perf hists browser: Do not exit when 'f' is pressed in 'report' mode perf top: Replace CTRL+z with 'f' as hotkey for enable/disable events perf annotate: Rename source_line_percent to source_line_samples perf annotate: Display total number of samples with --show-total-period perf tools: Ensure thread-stack is flushed perf top: Allow disabling/enabling events dynamicly perf evlist: Add toggle_enable() method perf trace: Fix race condition at the end of started workloads perf probe: Speed up perf probe --list by caching debuginfo perf probe: Show usage even if the last event is skipped perf tools: Move libtraceevent dynamic list to separated LDFLAGS variable perf tools: Fix a problem when opening old perf.data with different byte order perf tools: Ignore .config-detected in .gitignore perf probe: Fix to return error if no probe is added ...
2015-06-02writeback: add {CONFIG|BDI_CAP|FS}_CGROUP_WRITEBACKTejun Heo
cgroup writeback requires support from both bdi and filesystem sides. Add BDI_CAP_CGROUP_WRITEBACK and FS_CGROUP_WRITEBACK to indicate support and enable BDI_CAP_CGROUP_WRITEBACK on block based bdi's by default. Also, define CONFIG_CGROUP_WRITEBACK which is enabled if both MEMCG and BLK_CGROUP are enabled. inode_cgwb_enabled() which determines whether a given inode's both bdi and fs support cgroup writeback is added. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-28module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACINGPeter Zijlstra
Andrew worried about the overhead on small systems; only use the fancy code when either perf or tracing is enabled. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Requested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-27rcu: Remove prompt for RCU implementationPranith Kumar
The RCU implementation is chosen based on PREEMPT and SMP config options and is not really a user-selectable choice. This commit removes the menu entry, given that there is not much point in calling something a choice when there is in fact no choice.. The TINY_RCU, TREE_RCU, and PREEMPT_RCU Kconfig options continue to be selected based solely on the values of the PREEMPT and SMP options. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-05-27rcu: Make RCU able to tolerate undefined CONFIG_RCU_KTHREAD_PRIOPaul E. McKenney
This commit updates the initialization of the kthread_prio boot parameter so that RCU will build even when CONFIG_RCU_KTHREAD_PRIO is undefined. The kthread_prio boot parameter is set to CONFIG_RCU_KTHREAD_PRIO if that is defined, otherwise to 1 if CONFIG_RCU_BOOST is defined and to zero otherwise. This commit then makes CONFIG_RCU_KTHREAD_PRIO depend on CONFIG_RCU_EXPERT, so that Kconfig users won't be asked about CONFIG_RCU_KTHREAD_PRIO unless they want to be. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2015-05-27rcu: Make RCU able to tolerate undefined CONFIG_RCU_FANOUT_LEAFPaul E. McKenney
This commit introduces an RCU_FANOUT_LEAF C-preprocessor macro so that RCU will build even when CONFIG_RCU_FANOUT_LEAF is undefined. The RCU_FANOUT_LEAF macro is set to the value of CONFIG_RCU_FANOUT_LEAF when defined, otherwise it is set to 32 for 32-bit systems and 64 for 64-bit systems. This commit then makes CONFIG_RCU_FANOUT_LEAF depend on CONFIG_RCU_EXPERT, so that Kconfig users won't be asked about CONFIG_RCU_FANOUT_LEAF unless they want to be. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2015-05-27rcu: Make RCU able to tolerate undefined CONFIG_RCU_FANOUTPaul E. McKenney
This commit introduces an RCU_FANOUT C-preprocessor macro so that RCU will build even when CONFIG_RCU_FANOUT is undefined. The RCU_FANOUT macro is set to the value of CONFIG_RCU_FANOUT when defined, otherwise it is set to 32 for 32-bit systems and 64 for 64-bit systems. This commit then makes CONFIG_RCU_FANOUT depend on CONFIG_RCU_EXPERT, so that Kconfig users won't be asked about CONFIG_RCU_FANOUT unless they want to be. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2015-05-27rcu: Break dependency of RCU_FANOUT_LEAF on RCU_FANOUTPaul E. McKenney
RCU_FANOUT_LEAF's range and default values depend on the value of RCU_FANOUT, which at the time seemed like a cute way to save two lines of Kconfig code. However, adding a dependency from both of these Kconfig parameters on RCU_EXPERT requires that RCU_FANOUT_LEAF operate correctly even if RCU_FANOUT is undefined. This commit therefore allows RCU_FANOUT_LEAF to take on the full range of permitted values, even in cases where RCU_FANOUT is undefined. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: Eliminate redundant "default" as suggested by Pranith Kumar. ] Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2015-05-27rcu: Create RCU_EXPERT Kconfig and hide booleans behind itPaul E. McKenney
This commit creates an RCU_EXPERT Kconfig and hides the independent boolean RCU-related user-visible Kconfig parameters behind it, namely RCU_FAST_NO_HZ and RCU_BOOST. This prevents Kconfig from asking about these parameters unless the user really wants to be asked. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2015-05-27rcu: Convert CONFIG_RCU_FANOUT_EXACT to boot parameterPaul E. McKenney
The CONFIG_RCU_FANOUT_EXACT Kconfig parameter is used primarily (and perhaps only) by rcutorture to verify that RCU works correctly in specific rcu_node combining-tree configurations. It therefore does not make much sense have this as a question to people attempting to configure their kernels. So this commit creates an rcutree.rcu_fanout_exact= boot parameter that rcutorture can use, and eliminates the original CONFIG_RCU_FANOUT_EXACT Kconfig parameter. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2015-05-27rcu: Directly drive RCU_USER_QS from KconfigPaul E. McKenney
Currently, Kconfig will ask the user whether RCU_USER_QS should be set. This is silly because Kconfig already has all the information that it needs to set this parameter. This commit therefore directly drives the value of RCU_USER_QS via NO_HZ_FULL's "select" statement. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
2015-05-27rcu: Directly drive TASKS_RCU from KconfigPaul E. McKenney
Currently, Kconfig will ask the user whether TASKS_RCU should be set. This is silly because Kconfig already has all the information that it needs to set this parameter. This commit therefore directly drives the value of TASKS_RCU via "select" statements. Which means that as subsystems require TASKS_RCU, those subsystems will need to add "select" statements of their own. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2015-05-26sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsemTejun Heo
The cgroup side of threadgroup locking uses signal_struct->group_rwsem to synchronize against threadgroup changes. This per-process rwsem adds small overhead to thread creation, exit and exec paths, forces cgroup code paths to do lock-verify-unlock-retry dance in a couple places and makes it impossible to atomically perform operations across multiple processes. This patch replaces signal_struct->group_rwsem with a global percpu_rwsem cgroup_threadgroup_rwsem which is cheaper on the reader side and contained in cgroups proper. This patch converts one-to-one. This does make writer side heavier and lower the granularity; however, cgroup process migration is a fairly cold path, we do want to optimize thread operations over it and cgroup migration operations don't take enough time for the lower granularity to matter. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org>
2015-05-08perf_event: Don't allow vmalloc() backed perf on powerpcMichael Ellerman
On powerpc the perf event interrupt is not masked when interrupts are disabled, allowing it to function as an NMI. This causes problems if perf is using vmalloc. If we take a page fault on the vmalloc region the fault handler will fail the page fault because it detects we are coming in from an NMI (see do_hash_page()). We don't actually need or want vmalloc backed perf so just disable it on powerpc. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <linuxppc-dev@ozlabs.org> Cc: Andrew Morton <akpm@osdl.org> Cc: Anton Blanchard <anton@samba.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@ghostprotocols.net Cc: sukadev@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1430720799-18426-1-git-send-email-mpe@ellerman.id.au Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-18Merge tag 'docs-for-linus' of git://git.lwn.net/linux-2.6Linus Torvalds
Pull documentation updates from Jonathan Corbet: "Numerous fixes, the overdue removal of the i2o docs, some new Chinese translations, and, hopefully, the README fix that will end the flow of identical patches to that file" * tag 'docs-for-linus' of git://git.lwn.net/linux-2.6: (34 commits) Documentation/memcg: update memcg/kmem status Documentation: blackfin: Makefile: Typo building issue Documentation/vm/pagemap.txt: correct location of page-types tool Documentation/memory-barriers.txt: typo fix doc: Add guest_nice column to example output of `cat /proc/stat' Documentation/kernel-parameters: Move "eagerfpu" to its right place Documentation: gpio: Update ACPI part of the document to mention _DSD docs/completion.txt: Various tweaks and corrections doc: completion: context, scope and language fixes Documentation:Update Documentation/zh_CN/arm64/memory.txt Documentation:Update Documentation/zh_CN/arm64/booting.txt Documentation: Chinese translation of arm64/legacy_instructions.txt DocBook media: fix broken EIA hyperlink Documentation: tweak the maintainers entry README: Change gzip/bzip2 to xz compression format README: Update version number reference doc:pci: Fix typo in Documentation/PCI Documentation: drm: Use '->' when describing access through pointers. Documentation: Remove mentioning of block barriers Documentation/email-clients.txt: Fix one grammar mistake, add extra info about TB ...
2015-04-15kernel: conditionally support non-root users, groups and capabilitiesIulia Manda
There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf changes from Ingo Molnar: "Core kernel changes: - One of the more interesting features in this cycle is the ability to attach eBPF programs (user-defined, sandboxed bytecode executed by the kernel) to kprobes. This allows user-defined instrumentation on a live kernel image that can never crash, hang or interfere with the kernel negatively. (Right now it's limited to root-only, but in the future we might allow unprivileged use as well.) (Alexei Starovoitov) - Another non-trivial feature is per event clockid support: this allows, amongst other things, the selection of different clock sources for event timestamps traced via perf. This feature is sought by people who'd like to merge perf generated events with external events that were measured with different clocks: - cluster wide profiling - for system wide tracing with user-space events, - JIT profiling events etc. Matching perf tooling support is added as well, available via the -k, --clockid <clockid> parameter to perf record et al. (Peter Zijlstra) Hardware enablement kernel changes: - x86 Intel Processor Trace (PT) support: which is a hardware tracer on steroids, available on Broadwell CPUs. The hardware trace stream is directly output into the user-space ring-buffer, using the 'AUX' data format extension that was added to the perf core to support hardware constraints such as the necessity to have the tracing buffer physically contiguous. This patch-set was developed for two years and this is the result. A simple way to make use of this is to use BTS tracing, the PT driver emulates BTS output - available via the 'intel_bts' PMU. More explicit PT specific tooling support is in the works as well - will probably be ready by 4.2. (Alexander Shishkin, Peter Zijlstra) - x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware feature of Intel Xeon CPUs that allows the measurement and allocation/partitioning of caches to individual workloads. These kernel changes expose the measurement side as a new PMU driver, which exposes various QoS related PMU events. (The partitioning change is work in progress and is planned to be merged as a cgroup extension.) (Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P Waskiewicz Jr) - x86 Intel Haswell LBR call stack support: this is a new Haswell feature that allows the hardware recording of call chains, plus tooling support. To activate this feature you have to enable it via the new 'lbr' call-graph recording option: perf record --call-graph lbr perf report or: perf top --call-graph lbr This hardware feature is a lot faster than stack walk or dwarf based unwinding, but has some limitations: - It reuses the current LBR facility, so LBR call stack and branch record can not be enabled at the same time. - It is only available for user-space callchains. (Yan, Zheng) - x86 Intel Broadwell CPU support and various event constraints and event table fixes for earlier models. (Andi Kleen) - x86 Intel HT CPUs event scheduling workarounds. This is a complex CPU bug affecting the SNB,IVB,HSW families that results in counter value corruption. The mitigation code is automatically enabled and is transparent. (Maria Dimakopoulou, Stephane Eranian) The perf tooling side had a ton of changes in this cycle as well, so I'm only able to list the user visible changes here, in addition to the tooling changes outlined above: User visible changes affecting all tools: - Improve support of compressed kernel modules (Jiri Olsa) - Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo) - Bash completion for subcommands (Yunlong Song) - Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa) - Support missing -f to override perf.data file ownership. (Yunlong Song) - Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo) User visible changes in individual tools: 'perf data': New tool for converting perf.data to other formats, initially for the CTF (Common Trace Format) from LTTng (Jiri Olsa, Sebastian Siewior) 'perf diff': Add --kallsyms option (David Ahern) 'perf list': Allow listing events with 'tracepoint' prefix (Yunlong Song) Sort the output of the command (Yunlong Song) 'perf kmem': Respect -i option (Jiri Olsa) Print big numbers using thousands' group (Namhyung Kim) Allow -v option (Namhyung Kim) Fix alignment of slab result table (Namhyung Kim) 'perf probe': Support multiple probes on different binaries on the same command line (Masami Hiramatsu) Support unnamed union/structure members data collection. (Masami Hiramatsu) Check kprobes blacklist when adding new events. (Masami Hiramatsu) 'perf record': Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra) Support recording running/enabled time (Andi Kleen) 'perf sched': Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song) 'perf report' and 'perf top': Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo) Indicate which callchain entries are annotated in the TUI hists browser (Arnaldo Carvalho de Melo) Add pid/tid filtering to 'report' and 'script' commands (David Ahern) Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT events (Arnaldo Carvalho de Melo) 'perf stat': Report unsupported events properly (Suzuki K. Poulose) Output running time and run/enabled ratio in CSV mode (Andi Kleen) 'perf trace': Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo) Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo) Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo) Dump stack on segfaults (Arnaldo Carvalho de Melo) No need to explicitely enable evsels for workload started from perf, let it be enabled via perf_event_attr.enable_on_exec, removing some events that take place in the 'perf trace' before a workload is really started by it. (Arnaldo Carvalho de Melo) Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo) There's also been a ton of infrastructure work done, such as the split-out of perf's build system into tools/build/ and other changes - see the shortlog and changelog for details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits) perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init() perf evlist: Fix type for references to data_head/tail perf probe: Check the orphaned -x option perf probe: Support multiple probes on different binaries perf buildid-list: Fix segfault when show DSOs with hits perf tools: Fix cross-endian analysis perf tools: Fix error path to do closedir() when synthesizing threads perf tools: Fix synthesizing fork_event.ppid for non-main thread perf tools: Add 'I' event modifier for exclude_idle bit perf report: Don't call map__kmap if map is NULL. perf tests: Fix attr tests perf probe: Fix ARM 32 building error perf tools: Merge all perf_event_attr print functions perf record: Add clockid parameter perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10 perf sched replay: Support using -f to override perf.data file ownership perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task perf sched replay: Fix the segmentation fault problem caused by pr_err in threads perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations ...
2015-04-11Documentation/memcg: update memcg/kmem statusVladimir Davydov
Memcg/kmem reclaim support has been finally merged. Reflect this in the documentation. Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-04-02bpf: Fix the build on BPF_SYSCALL=y && !CONFIG_TRACING kernels, make it more ↵Ingo Molnar
configurable So bpf_tracing.o depends on CONFIG_BPF_SYSCALL - but that's not its only dependency, it also depends on the tracing infrastructure and on kprobes, without which it will fail to build with: In file included from kernel/trace/bpf_trace.c:14:0: kernel/trace/trace.h: In function ‘trace_test_and_set_recursion’: kernel/trace/trace.h:491:28: error: ‘struct task_struct’ has no member named ‘trace_recursion’ unsigned int val = current->trace_recursion; [...] It took quite some time to trigger this build failure, because right now BPF_SYSCALL is very obscure, depends on CONFIG_EXPERT. So also make BPF_SYSCALL more configurable, not just under CONFIG_EXPERT. If BPF_SYSCALL, tracing and kprobes are enabled then enable the bpf_tracing gateway as well. We might want to make this an interactive option later on, although I'd not complicate it unnecessarily: enabling BPF_SYSCALL is enough of an indicator that the user wants BPF support. Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-26rcu: Add Kconfig option to expedite grace periods during bootPaul E. McKenney
This commit adds a CONFIG_RCU_EXPEDITE_BOOT Kconfig parameter that emulates a very early boot rcu_expedite_gp(). A late-boot call to rcu_end_inkernel_boot() will provide the corresponding rcu_unexpedite_gp(). The late-boot call to rcu_end_inkernel_boot() should be made just before init is spawned. According to Arjan: > To show the boot time, I'm using the timestamp of the "Write protecting" > line, that's pretty much the last thing we print prior to ring 3 execution. > > A kernel with default RCU behavior (inside KVM, only virtual devices) > looks like this: > > [ 0.038724] Write protecting the kernel read-only data: 10240k > > a kernel with expedited RCU (using the command line option, so that I > don't have to recompile between measurements and thus am completely > oranges-to-oranges) > > [ 0.031768] Write protecting the kernel read-only data: 10240k > > which, in percentage, is an 18% improvement. Reported-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Arjan van de Ven <arjan@linux.intel.com>
2015-02-19Merge branch 'kconfig' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kconfig updates from Michal Marek: "Yann E Morin was supposed to take over kconfig maintainership, but this hasn't happened. So I'm sending a few kconfig patches that I collected: - Fix for missing va_end in kconfig - merge_config.sh displays used if given too few arguments - s/boolean/bool/ in Kconfig files for consistency, with the plan to only support bool in the future" * 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: kconfig: use va_end to match corresponding va_start merge_config.sh: Display usage if given too few arguments kconfig: use bool instead of boolean for type definition attributes
2015-02-19Merge branch 'misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull misc kbuild changes from Michal Marek: "Just a few non-critical kbuild changes: - builddeb adds the actual distribution name in the changelog - documentation fixes" * 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: kbuild: trivial - fix the help doc of CONFIG_CC_OPTIMIZE_FOR_SIZE kbuild: Update documentation of clean-files and clean-dirs builddeb: Try to determine distribution builddeb: Update year and git repository URL in debian/copyright
2015-02-13init: remove CONFIG_INIT_FALLBACKAndy Lutomirski
CONFIG_INIT_FALLBACK adds config bloat without an obvious use case that makes it worth keeping around. Delete it. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chuck Ebbert <cebbert.lkml@gmail.com> Cc: Frank Rowand <frowand.list@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Rob Landley <rob@landley.net> Cc: Shuah Khan <shuah.kh@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-15Merge branches 'doc.2015.01.07a', 'fixes.2015.01.15a', ↵Paul E. McKenney
'preempt.2015.01.06a', 'srcu.2015.01.06a', 'stall.2015.01.16a' and 'torture.2015.01.11a' into HEAD doc.2015.01.07a: Documentation updates. fixes.2015.01.15a: Miscellaneous fixes. preempt.2015.01.06a: Changes to handling of lists of preempted tasks. srcu.2015.01.06a: SRCU updates. stall.2015.01.16a: RCU CPU stall-warning updates and fixes. torture.2015.01.11a: RCU torture-test updates and fixes.
2015-01-15rcu: Optionally run grace-period kthreads at real-time priorityPaul E. McKenney
Recent testing has shown that under heavy load, running RCU's grace-period kthreads at real-time priority can improve performance (according to 0day test robot) and reduce the incidence of RCU CPU stall warnings. However, most systems do just fine with the default non-realtime priorities for these kthreads, and it does not make sense to expose the entire user base to any risk stemming from this change, given that this change is of use only to a few users running extremely heavy workloads. Therefore, this commit allows users to specify realtime priorities for the grace-period kthreads, but leaves them running SCHED_OTHER by default. The realtime priority may be specified at build time via the RCU_KTHREAD_PRIO Kconfig parameter, or at boot time via the rcutree.kthread_prio parameter. Either way, 0 says to continue the default SCHED_OTHER behavior and values from 1-99 specify that priority of SCHED_FIFO behavior. Note that a value of 0 is not permitted when the RCU_BOOST Kconfig parameter is specified. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-01-08kbuild: trivial - fix the help doc of CONFIG_CC_OPTIMIZE_FOR_SIZEMasahiro Yamada
Other than GCC, we have another choice, Clang for building the kernel these days. It seems better to say "compiler" rather than "gcc". Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-01-07kconfig: use bool instead of boolean for type definition attributesChristoph Jaeger
Support for keyword 'boolean' will be dropped later on. No functional change. Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com Signed-off-by: Christoph Jaeger <cj@linux.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-01-06rcu: Make SRCU optional by using CONFIG_SRCUPranith Kumar
SRCU is not necessary to be compiled by default in all cases. For tinification efforts not compiling SRCU unless necessary is desirable. The current patch tries to make compiling SRCU optional by introducing a new Kconfig option CONFIG_SRCU which is selected when any of the components making use of SRCU are selected. If we do not select CONFIG_SRCU, srcu.o will not be compiled at all. text data bss dec hex filename 2007 0 0 2007 7d7 kernel/rcu/srcu.o Size of arch/powerpc/boot/zImage changes from text data bss dec hex filename 831552 64180 23944 919676 e087c arch/powerpc/boot/zImage : before 829504 64180 23952 917636 e0084 arch/powerpc/boot/zImage : after so the savings are about ~2000 bytes. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com> CC: Josh Triplett <josh@joshtriplett.org> CC: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]
2015-01-06rcu: Remove "select IRQ_WORK" from config TREE_RCULai Jiangshan
The 48a7639ce80c ("rcu: Make callers awaken grace-period kthread") removed the irq_work_queue(), so the TREE_RCU doesn't need irq work any more. This commit therefore updates RCU's Kconfig and Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-12-10init: allow CONFIG_INIT_FALLBACK=n to disable defaults if init= failsAndy Lutomirski
If a user puts init=/whatever on the command line and /whatever can't be run, then the kernel will try a few default options before giving up. If init=/whatever came from a bootloader prompt, then this is unexpected but probably harmless. On the other hand, if it comes from a script (e.g. a tool like virtme or perhaps a future kselftest script), then the fallbacks are likely to exist, but they'll do the wrong thing. For example, they might unexpectedly invoke systemd. This adds a config option CONFIG_INIT_FALLBACK. If unset, then a failure to run the specified init= process be fatal. The tentative plan is to remove CONFIG_INIT_FALLBACK for 3.20. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Rob Landley <rob@landley.net> Cc: Chuck Ebbert <cebbert.lkml@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shuah Khan <shuah.kh@samsung.com> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10mm: move page->mem_cgroup bad page handling into generic codeJohannes Weiner
Now that the external page_cgroup data structure and its lookup is gone, let the generic bad_page() check for page->mem_cgroup sanity. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Tejun Heo <tj@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10mm/numa balancing: rearrange Kconfig entryAneesh Kumar K.V
Add the default enable config option after the NUMA_BALANCING option so that it appears related in the nconfig interface. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10kernel: res_counter: remove the unused APIJohannes Weiner
All memory accounting and limiting has been switched over to the lockless page counters. Bye, res_counter! [akpm@linux-foundation.org: update Documentation/cgroups/memory.txt] [mhocko@suse.cz: ditch the last remainings of res_counter] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10mm: hugetlb_cgroup: convert to lockless page countersJohannes Weiner
Abandon the spinlock-protected byte counters in favor of the unlocked page counters in the hugetlb controller as well. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10mm: memcontrol: lockless page countersJohannes Weiner
Memory is internally accounted in bytes, using spinlock-protected 64-bit counters, even though the smallest accounting delta is a page. The counter interface is also convoluted and does too many things. Introduce a new lockless word-sized page counter API, then change all memory accounting over to it. The translation from and to bytes then only happens when interfacing with userspace. The removed locking overhead is noticable when scaling beyond the per-cpu charge caches - on a 4-socket machine with 144-threads, the following test shows the performance differences of 288 memcgs concurrently running a page fault benchmark: vanilla: 18631648.500498 task-clock (msec) # 140.643 CPUs utilized ( +- 0.33% ) 1,380,638 context-switches # 0.074 K/sec ( +- 0.75% ) 24,390 cpu-migrations # 0.001 K/sec ( +- 8.44% ) 1,843,305,768 page-faults # 0.099 M/sec ( +- 0.00% ) 50,134,994,088,218 cycles # 2.691 GHz ( +- 0.33% ) <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 8,049,712,224,651 instructions # 0.16 insns per cycle ( +- 0.04% ) 1,586,970,584,979 branches # 85.176 M/sec ( +- 0.05% ) 1,724,989,949 branch-misses # 0.11% of all branches ( +- 0.48% ) 132.474343877 seconds time elapsed ( +- 0.21% ) lockless: 12195979.037525 task-clock (msec) # 133.480 CPUs utilized ( +- 0.18% ) 832,850 context-switches # 0.068 K/sec ( +- 0.54% ) 15,624 cpu-migrations # 0.001 K/sec ( +- 10.17% ) 1,843,304,774 page-faults # 0.151 M/sec ( +- 0.00% ) 32,811,216,801,141 cycles # 2.690 GHz ( +- 0.18% ) <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 9,999,265,091,727 instructions # 0.30 insns per cycle ( +- 0.10% ) 2,076,759,325,203 branches # 170.282 M/sec ( +- 0.12% ) 1,656,917,214 branch-misses # 0.08% of all branches ( +- 0.55% ) 91.369330729 seconds time elapsed ( +- 0.45% ) On top of improved scalability, this also gets rid of the icky long long types in the very heart of memcg, which is great for 32 bit and also makes the code a lot more readable. Notable differences between the old and new API: - res_counter_charge() and res_counter_charge_nofail() become page_counter_try_charge() and page_counter_charge() resp. to match the more common kernel naming scheme of try_do()/do() - res_counter_uncharge_until() is only ever used to cancel a local counter and never to uncharge bigger segments of a hierarchy, so it's replaced by the simpler page_counter_cancel() - res_counter_set_limit() is replaced by page_counter_limit(), which expects its callers to serialize against themselves - res_counter_memparse_write_strategy() is replaced by page_counter_limit(), which rounds down to the nearest page size - rather than up. This is more reasonable for explicitely requested hard upper limits. - to keep charging light-weight, page_counter_try_charge() charges speculatively, only to roll back if the result exceeds the limit. Because of this, a failing bigger charge can temporarily lock out smaller charges that would otherwise succeed. The error is bounded to the difference between the smallest and the biggest possible charge size, so for memcg, this means that a failing THP charge can send base page charges into reclaim upto 2MB (4MB) before the limit would have been reached. This should be acceptable. [akpm@linux-foundation.org: add includes for WARN_ON_ONCE and memparse] [akpm@linux-foundation.org: add includes for WARN_ON_ONCE, memparse, strncmp, and PAGE_SIZE] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-20Merge branch 'rcu/next' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU updates from Paul E. McKenney: - Streamline RCU's use of per-CPU variables, shifting from "cpu" arguments to functions to "this_"-style per-CPU variable accessors. - Signal-handling RCU updates. - Real-time updates. - Torture-test updates. - Miscellaneous fixes. - Documentation updates. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-29rcu: Remove redundant TREE_PREEMPT_RCU config optionPranith Kumar
PREEMPT_RCU and TREE_PREEMPT_RCU serve the same function after TINY_PREEMPT_RCU has been removed. This patch removes TREE_PREEMPT_RCU and uses PREEMPT_RCU config option in its place. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-10-29rcu: Unify boost and kthread prioritiesClark Williams
Rename CONFIG_RCU_BOOST_PRIO to CONFIG_RCU_KTHREAD_PRIO and use this value for both the per-CPU kthreads (rcuc/N) and the rcu boosting threads (rcub/n). Also, create the module_parameter rcutree.kthread_prio to be used on the kernel command line at boot to set a new value (rcutree.kthread_prio=N). Signed-off-by: Clark Williams <clark.williams@gmail.com> [ paulmck: Ported to rcu/dev, applied Paul Bolle and Peter Zijlstra feedback. ] Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-10-28init/Kconfig: move RCU_NOCB_CPU dependencies to choiceStefan Hengelein
Every choice item of the "Build-forced no-CBs CPUs" choice had a dependency to RCU_NOCB_CPU. It's more comprehensible if the choice itself has the dependency instead of every choice item. The choice itself doesn't need to be visible if there are no items selectable (i.e. on arch/frv) or RCU_NOCB_CPU is not defined. Signed-off-by: Stefan Hengelein <stefan.hengelein@fau.de> Signed-off-by: Andreas Ruprecht <rupran@einserver.de> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-10-27bpf: split eBPF out of NETAlexei Starovoitov
introduce two configs: - hidden CONFIG_BPF to select eBPF interpreter that classic socket filters depend on - visible CONFIG_BPF_SYSCALL (default off) that tracing and sockets can use that solves several problems: - tracing and others that wish to use eBPF don't need to depend on NET. They can use BPF_SYSCALL to allow loading from userspace or select BPF to use it directly from kernel in NET-less configs. - in 3.18 programs cannot be attached to events yet, so don't force it on - when the rest of eBPF infra is there in 3.19+, it's still useful to switch it off to minimize kernel size bloat-o-meter on x64 shows: add/remove: 0/60 grow/shrink: 0/2 up/down: 0/-15601 (-15601) tested with many different config combinations. Hopefully didn't miss anything. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>