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2014-01-21mm: add overcommit_kbytes sysctl variableJerome Marchand1-3/+8
Some applications that run on HPC clusters are designed around the availability of RAM and the overcommit ratio is fine tuned to get the maximum usage of memory without swapping. With growing memory, the 1%-of-all-RAM grain provided by overcommit_ratio has become too coarse for these workload (on a 2TB machine it represents no less than 20GB). This patch adds the new overcommit_kbytes sysctl variable that allow a much finer grain. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix nommu build] Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21fsnotify: remove pointless NULL initializersJan Kara2-5/+0
We usually rely on the fact that struct members not specified in the initializer are set to NULL. So do that with fsnotify function pointers as well. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21fsnotify: remove .should_send_event callbackJan Kara2-20/+1
After removing event structure creation from the generic layer there is no reason for separate .should_send_event and .handle_event callbacks. So just remove the first one. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21fsnotify: do not share events between notification groupsJan Kara2-10/+12
Currently fsnotify framework creates one event structure for each notification event and links this event into all interested notification groups. This is done so that we save memory when several notification groups are interested in the event. However the need for event structure shared between inotify & fanotify bloats the event structure so the result is often higher memory consumption. Another problem is that fsnotify framework keeps path references with outstanding events so that fanotify can return open file descriptors with its events. This has the undesirable effect that filesystem cannot be unmounted while there are outstanding events - a regression for inotify compared to a situation before it was converted to fsnotify framework. For fanotify this problem is hard to avoid and users of fanotify should kind of expect this behavior when they ask for file descriptors from notified files. This patch changes fsnotify and its users to create separate event structure for each group. This allows for much simpler code (~400 lines removed by this patch) and also smaller event structures. For example on 64-bit system original struct fsnotify_event consumes 120 bytes, plus additional space for file name, additional 24 bytes for second and each subsequent group linking the event, and additional 32 bytes for each inotify group for private data. After the conversion inotify event consumes 48 bytes plus space for file name which is considerably less memory unless file names are long and there are several groups interested in the events (both of which are uncommon). Fanotify event fits in 56 bytes after the conversion (fanotify doesn't care about file names so its events don't have to have it allocated). A win unless there are four or more fanotify groups interested in the event. The conversion also solves the problem with unmount when only inotify is used as we don't have to grab path references for inotify events. [hughd@google.com: fanotify: fix corruption preventing startup] Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-20Merge branch 'timers-core-for-linus' of ↵Linus Torvalds8-254/+190
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer changes from Ingo Molnar: - ARM clocksource/clockevent improvements and fixes - generic timekeeping updates: TAI fixes/improvements, cleanups - Posix cpu timer cleanups and improvements - dynticks updates: full dynticks bugfixes, optimizations and cleanups * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) clocksource: Timer-sun5i: Switch to sched_clock_register() timekeeping: Remove comment that's mostly out of date rtc-cmos: Add an alarm disable quirk timekeeper: fix comment typo for tk_setup_internals() timekeeping: Fix missing timekeeping_update in suspend path timekeeping: Fix CLOCK_TAI timer/nanosleep delays tick/timekeeping: Call update_wall_time outside the jiffies lock timekeeping: Avoid possible deadlock from clock_was_set_delayed timekeeping: Fix potential lost pv notification of time change timekeeping: Fix lost updates to tai adjustment clocksource: sh_cmt: Add clk_prepare/unprepare support clocksource: bcm_kona_timer: Remove unused bcm_timer_ids clocksource: vt8500: Remove deprecated IRQF_DISABLED clocksource: tegra: Remove deprecated IRQF_DISABLED clocksource: misc drivers: Remove deprecated IRQF_DISABLED clocksource: sh_mtu2: Remove unnecessary platform_set_drvdata() clocksource: sh_tmu: Remove unnecessary platform_set_drvdata() clocksource: armada-370-xp: Enable timer divider only when needed clocksource: clksrc-of: Warn if no clock sources are found clocksource: orion: Switch to sched_clock_register() ...
2014-01-20Merge branch 'sched-core-for-linus' of ↵Linus Torvalds24-323/+3087
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler changes from Ingo Molnar: - Add the initial implementation of SCHED_DEADLINE support: a real-time scheduling policy where tasks that meet their deadlines and periodically execute their instances in less than their runtime quota see real-time scheduling and won't miss any of their deadlines. Tasks that go over their quota get delayed (Available to privileged users for now) - Clean up and fix preempt_enable_no_resched() abuse all around the tree - Do sched_clock() performance optimizations on x86 and elsewhere - Fix and improve auto-NUMA balancing - Fix and clean up the idle loop - Apply various cleanups and fixes * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits) sched: Fix __sched_setscheduler() nice test sched: Move SCHED_RESET_ON_FORK into attr::sched_flags sched: Fix up attr::sched_priority warning sched: Fix up scheduler syscall LTP fails sched: Preserve the nice level over sched_setscheduler() and sched_setparam() calls sched/core: Fix htmldocs warnings sched/deadline: No need to check p if dl_se is valid sched/deadline: Remove unused variables sched/deadline: Fix sparse static warnings m68k: Fix build warning in mac_via.h sched, thermal: Clean up preempt_enable_no_resched() abuse sched, net: Fixup busy_loop_us_clock() sched, net: Clean up preempt_enable_no_resched() abuse sched/preempt: Fix up missed PREEMPT_NEED_RESCHED folding sched/preempt, locking: Rework local_bh_{dis,en}able() sched/clock, x86: Avoid a runtime condition in native_sched_clock() sched/clock: Fix up clear_sched_clock_stable() sched/clock, x86: Use a static_key for sched_clock_stable sched/clock: Remove local_irq_disable() from the clocks sched/clock, x86: Rewrite cyc2ns() to avoid the need to disable IRQs ...
2014-01-20Merge branch 'perf-core-for-linus' of ↵Linus Torvalds3-37/+96
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Kernel side changes: - Add Intel RAPL energy counter support (Stephane Eranian) - Clean up uprobes (Oleg Nesterov) - Optimize ring-buffer writes (Peter Zijlstra) Tooling side changes, user visible: - 'perf diff': - Add column colouring improvements (Ramkumar Ramachandra) - 'perf kvm': - Add guest related improvements, including allowing to specify a directory with guest specific /proc information (Dongsheng Yang) - Add shell completion support (Ramkumar Ramachandra) - Add '-v' option (Dongsheng Yang) - Support --guestmount (Dongsheng Yang) - 'perf probe': - Support showing source code, asking for variables to be collected at probe time and other 'perf probe' operations that use DWARF information. This supports only binaries with debugging information at this time, detached debuginfo (aka debuginfo packages) support should come in later patches (Masami Hiramatsu) - 'perf record': - Rename --no-delay option to --no-buffering, better reflecting its purpose and freeing up '--delay' to take the place of '--initial-delay', so that 'record' and 'stat' are consistent (Arnaldo Carvalho de Melo) - Default the -t/--thread option to no inheritance (Adrian Hunter) - Make per-cpu mmaps the default (Adrian Hunter) - 'perf report': - Improve callchain processing performance (Frederic Weisbecker) - Retain bfd reference to lookup source line numbers, greatly optimizing, among other use cases, 'perf report -s srcline' (Adrian Hunter) - Improve callchain processing performance even more (Namhyung Kim) - Add a perf.data file header window in the 'perf report' TUI, associated with the 'i' hotkey, providing a counterpart to the --header option in the stdio UI (Namhyung Kim) - 'perf script': - Add an option in 'perf script' to print the source line number (Adrian Hunter) - Add --header/--header-only options to 'script' and 'report', the default is not tho show the header info, but as this has been the default for some time, leave a single line explaining how to obtain that information (Jiri Olsa) - Add options to show comm, fork, exit and mmap PERF_RECORD_ events (Namhyung Kim) - Print callchains and symbols if they exist (David Ahern) - 'perf timechart' - Add backtrace support to CPU info - Print pid along the name - Add support for CPU topology - Add new option --highlight'ing threads, be it by name or, if a numeric value is provided, that run more than given duration (Stanislav Fomichev) - 'perf top': - Make 'perf top -g' refer to callchains, for consistency with other tools (David Ahern) - 'perf trace': - Handle old kernels where the "raw_syscalls" tracepoints were called plain "syscalls" (David Ahern) - Remove thread summary coloring, by Pekka Enberg. - Honour -m option in 'trace', the tool was offering the option to set the mmap size, but wasn't using it when doing the actual mmap on the events file descriptors (Jiri Olsa) - generic: - Backport libtraceevent plugin support (trace-cmd repository, with plugins for jbd2, hrtimer, kmem, kvm, mac80211, sched_switch, function, xen, scsi, cfg80211 (Jiri Olsa) - Print session information only if --stdio is given (Namhyung Kim) Tooling side changes, developer visible (plumbing): - Improve 'perf probe' exit path, release resources (Masami Hiramatsu) - Improve libtraceevent plugins exit path, allowing the registering of an unregister handler to be called at exit time (Namhyung Kim) - Add an alias to the build test makefile (make -C tools/perf build-test) (Namhyung Kim) - Get rid of die() and friends (good riddance!) in libtraceevent (Namhyung Kim) - Fix cross build problems related to pkgconfig and CROSS_COMPILE not being propagated to the feature tests, leading to features being tested in the host and then being enabled on the target (Mark Rutland) - Improve forked workload error reporting by sending the errno in the signal data queueing integer field, using sigqueue and by doing the signal setup in the evlist methods, removing open coded equivalents in various tools (Arnaldo Carvalho de Melo) - Do more auto exit cleanup chores in the 'evlist' destructor, so that the tools don't have to all do that sequence (Arnaldo Carvalho de Melo) - Pack 'struct perf_session_env' and 'struct trace' (Arnaldo Carvalho de Melo) - Add test for building detached source tarballs (Arnaldo Carvalho de Melo) - Move some header files (tools/perf/ to tools/include/ to make them available to other tools/ dwelling codebases (Namhyung Kim) - Move logic to warn about kptr_restrict'ed kernels to separate function in 'report' (Arnaldo Carvalho de Melo) - Move hist browser selection code to separate function (Arnaldo Carvalho de Melo) - Move histogram entries collapsing to separate function (Arnaldo Carvalho de Melo) - Introduce evlist__for_each() & friends (Arnaldo Carvalho de Melo) - Automate setup of FEATURE_CHECK_(C|LD)FLAGS-all variables (Jiri Olsa) - Move arch setup into seprate Makefile (Jiri Olsa) - Make libtraceevent install target quieter (Jiri Olsa) - Make tests/make output more compact (Jiri Olsa) - Ignore generated files in feature-checks (Chunwei Chen) - Introduce pevent_filter_strerror() in libtraceevent, similar in purpose to libc's strerror() function (Namhyung Kim) - Use perf_data_file methods to write output file in 'record' and 'inject' (Jiri Olsa) - Use pr_*() functions where applicable in 'report' (Namhyumg Kim) - Add 'machine' 'addr_location' struct to have full picture (machine, thread, map, symbol, addr) for a (partially) resolved address, reducing function signatures (Arnaldo Carvalho de Melo) - Reduce code duplication in the histogram entry creation/insertion (Arnaldo Carvalho de Melo) - Auto allocate annotation histogram data structures (Arnaldo Carvalho de Melo) - No need to test against NULL before calling free, also set freed memory in struct pointers to NULL, to help fixing use after free bugs (Arnaldo Carvalho de Melo) - Rename some struct DSO binary_type related members and methods, to clarify its purpose and need for differentiation (symtab_type, ie one is about the files .text, CFI, etc, i.e. its binary contents, and the other is about where the symbol table came from (Arnaldo Carvalho de Melo) - Convert to new topic libraries, starting with an API one (sysfs, debugfs, etc), renaming liblk in the process (Borislav Petkov) - Get rid of some more panic() like error handling in libtraceevent. (Namhyung Kim) - Get rid of panic() like calls in libtraceevent (Namyung Kim) - Start carving out symbol parsing routines (perf, just moving routines to topic files in tools/lib/symbol/, tools that want to use it need to integrate it directly, ie no tools/lib/symbol/Makefile is provided (Arnaldo Carvalho de Melo) - Assorted refactoring patches, moving code around and adding utility evlist methods that will be used in the IPT patchset (Adrian Hunter) - Assorted mmap_pages handling fixes (Adrian Hunter) - Several man pages typo fixes (Dongsheng Yang) - Get rid of several die() calls in libtraceevent (Namhyung Kim) - Use basename() in a more robust way, to avoid problems related to different system library implementations for that function (Stephane Eranian) - Remove open coded management of short_name_allocated member (Adrian Hunter) - Several cleanups in the "dso" methods, constifying some parameters and renaming some fields to clarify its purpose (Arnaldo Carvalho de Melo) - Add per-feature check flags, fixing libunwind related build problems on some architectures (Jean Pihet) - Do not disable source line lookup just because of one failure. (Adrian Hunter) - Several 'perf kvm' man page corrections (Dongsheng Yang) - Correct the message in feature-libnuma checking, swowing the right devel package names for various distros (Dongsheng Yang) - Polish 'readn()' function and introduce its counterpart, 'writen()' (Jiri Olsa) - Start moving timechart state from global variables to a 'perf_tool' derived 'timechart' struct (Arnaldo Carvalho de Melo) ... and lots of fixes and improvements I forgot to list" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (282 commits) perf tools: Remove unnecessary callchain cursor state restore on unmatch perf callchain: Spare double comparison of callchain first entry perf tools: Do proper comm override error handling perf symbols: Export elf_section_by_name and reuse perf probe: Release all dynamically allocated parameters perf probe: Release allocated probe_trace_event if failed perf tools: Add 'build-test' make target tools lib traceevent: Unregister handler when xen plugin is unloaded tools lib traceevent: Unregister handler when scsi plugin is unloaded tools lib traceevent: Unregister handler when jbd2 plugin is is unloaded tools lib traceevent: Unregister handler when cfg80211 plugin is unloaded tools lib traceevent: Unregister handler when mac80211 plugin is unloaded tools lib traceevent: Unregister handler when sched_switch plugin is unloaded tools lib traceevent: Unregister handler when kvm plugin is unloaded tools lib traceevent: Unregister handler when kmem plugin is unloaded tools lib traceevent: Unregister handler when hrtimer plugin is unloaded tools lib traceevent: Unregister handler when function plugin is unloaded tools lib traceevent: Add pevent_unregister_print_function() tools lib traceevent: Add pevent_unregister_event_handler() tools lib traceevent: fix pointer-integer size mismatch ...
2014-01-20Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds8-74/+251
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: - add RCU torture scripts/tooling - static analysis improvements - update RCU documentation - miscellaneous fixes * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) rcu: Remove "extern" from function declarations in kernel/rcu/rcu.h rcu: Remove "extern" from function declarations in include/linux/*rcu*.h rcu/torture: Dynamically allocate SRCU output buffer to avoid overflow rcu: Don't activate RCU core on NO_HZ_FULL CPUs rcu: Warn on allegedly impossible rcu_read_unlock_special() from irq rcu: Add an RCU_INITIALIZER for global RCU-protected pointers rcu: Make rcu_assign_pointer's assignment volatile and type-safe bonding: Use RCU_INIT_POINTER() for better overhead and for sparse rcu: Add comment on evaluate-once properties of rcu_assign_pointer(). rcu: Provide better diagnostics for blocking in RCU callback functions rcu: Improve SRCU's grace-period comments rcu: Fix CONFIG_RCU_FANOUT_EXACT for odd fanout/leaf values rcu: Fix coccinelle warnings rcutorture: Stop tracking FSF's postal address rcutorture: Move checkarg to functions.sh rcutorture: Flag errors and warnings with color coding rcutorture: Record results from repeated runs of the same test scenario rcutorture: Test summary at end of run with less chattiness rcutorture: Update comment in kvm.sh listing typical RCU trace events rcutorture: Add tracing-enabled version of TREE08 ...
2014-01-20Merge branch 'core-locking-for-linus' of ↵Linus Torvalds6-50/+242
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core locking changes from Ingo Molnar: - futex performance increases: larger hashes, smarter wakeups - mutex debugging improvements - lots of SMP ordering documentation updates - introduce the smp_load_acquire(), smp_store_release() primitives. (There are WIP patches that make use of them - not yet merged) - lockdep micro-optimizations - lockdep improvement: better cover IRQ contexts - liblockdep at last. We'll continue to monitor how useful this is * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) futexes: Fix futex_hashsize initialization arch: Re-sort some Kbuild files to hopefully help avoid some conflicts futexes: Avoid taking the hb->lock if there's nothing to wake up futexes: Document multiprocessor ordering guarantees futexes: Increase hash table size for better performance futexes: Clean up various details arch: Introduce smp_load_acquire(), smp_store_release() arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h arch: Move smp_mb__{before,after}_atomic_{inc,dec}.h into asm/atomic.h locking/doc: Rename LOCK/UNLOCK to ACQUIRE/RELEASE mutexes: Give more informative mutex warning in the !lock->owner case powerpc: Full barrier for smp_mb__after_unlock_lock() rcu: Apply smp_mb__after_unlock_lock() to preserve grace periods Documentation/memory-barriers.txt: Downgrade UNLOCK+BLOCK locking: Add an smp_mb__after_unlock_lock() for UNLOCK+BLOCK barrier Documentation/memory-barriers.txt: Document ACCESS_ONCE() Documentation/memory-barriers.txt: Prohibit speculative writes Documentation/memory-barriers.txt: Add long atomic examples to memory-barriers.txt Documentation/memory-barriers.txt: Add needed ACCESS_ONCE() calls to memory-barriers.txt Revert "smp/cpumask: Make CONFIG_CPUMASK_OFFSTACK=y usable without debug dependency" ...
2014-01-20Merge branch 'core-debug-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core debug changes from Ingo Molnar: "Currently there are two methods to set the panic_timeout: via 'panic=X' boot commandline option, or via /proc/sys/kernel/panic. This tree adds a third panic_timeout configuration method: configuration via Kconfig, via CONFIG_PANIC_TIMEOUT=X - useful to distros that generally want their kernel defaults to come with the .config. CONFIG_PANIC_TIMEOUT defaults to 0, which was the previous default value of panic_timeout. Doing that unearthed a few arch trickeries regarding arch-special panic_timeout values and related complications - hopefully all resolved to the satisfaction of everyone" * 'core-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: powerpc: Clean up panic_timeout usage MIPS: Remove panic_timeout settings panic: Make panic_timeout configurable
2014-01-17Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace fixes from Eric Biederman: "This is a set of 3 regression fixes. This fixes /proc/mounts when using "ip netns add <netns>" to display the actual mount point. This fixes a regression in clone that broke lxc-attach. This fixes a regression in the permission checks for mounting /proc that made proc unmountable if binfmt_misc was in use. Oops. My apologies for sending this pull request so late. Al Viro gave interesting review comments about the d_path fix that I wanted to address in detail before I sent this pull request. Unfortunately a bad round of colds kept from addressing that in detail until today. The executive summary of the review was: Al: Is patching d_path really sufficient? The prepend_path, d_path, d_absolute_path, and __d_path family of functions is a really mess. Me: Yes, patching d_path is really sufficient. Yes, the code is mess. No it is not appropriate to rewrite all of d_path for a regression that has existed for entirely too long already, when a two line change will do" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: vfs: Fix a regression in mounting proc fork: Allow CLONE_PARENT after setns(CLONE_NEWPID) vfs: In d_path don't call d_dname on a mount point
2014-01-16sched: Fix __sched_setscheduler() nice testPeter Zijlstra1-1/+2
With the introduction of sched_attr::sched_nice we need to check if we've got permission to actually change the nice value. Daniel found that can_nice() would always fail; and upon inspection it turns out that can_nice() only tests to see if we can lower the nice value, but it doesn't validate if we're lowering or not. Therefore amend the test to only call can_nice() when we lower the nice value. Reported-and-Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: raistlin@linux.it Cc: juri.lelli@gmail.com Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Fixes: d50dde5a10f3 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI") Link: http://lkml.kernel.org/r/20140116165425.GA9481@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16futexes: Fix futex_hashsize initializationHeiko Carstens1-2/+4
"futexes: Increase hash table size for better performance" introduces a new alloc_large_system_hash() call. alloc_large_system_hash() however may allocate less memory than requested, e.g. limited by MAX_ORDER. Hence pass a pointer to alloc_large_system_hash() which will contain the hash shift when the function returns. Afterwards correctly set futex_hashsize. Fixes a crash on s390 where the requested allocation size was 4MB but only 1MB was allocated. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Darren Hart <dvhart@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Waiman Long <Waiman.Long@hp.com> Cc: Jason Low <jason.low2@hp.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Link: http://lkml.kernel.org/r/20140116135450.GA4345@osiris Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16Merge branch 'perf/urgent' into perf/coreIngo Molnar15-116/+162
Pick up the latest fixes, refresh the development tree. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16sched: Move SCHED_RESET_ON_FORK into attr::sched_flagsPeter Zijlstra1-14/+28
I noticed the new sched_{set,get}attr() calls didn't properly deal with the SCHED_RESET_ON_FORK hack. Instead of propagating the flags in high bits nonsense use the brand spanking new attr::sched_flags field. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Dario Faggioli <raistlin@linux.it> Link: http://lkml.kernel.org/r/20140115162242.GJ31570@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16sched: Fix up attr::sched_priority warningPeter Zijlstra1-2/+1
Fengguang Wu reported the following build warning: > kernel/sched/core.c:3067 __sched_setscheduler() warn: unsigned 'attr->sched_priority' is never less than zero. Since it doesn't make sense for attr::sched_priority to be negative, remove the check, since we already test for an upper limit any actual negative values passed in through the old param::sched_priority field will still be detected. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Dario Faggioli <raistlin@linux.it> Fixes: d50dde5a10f3 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI") Link: http://lkml.kernel.org/n/tip-fid9nalzii2r5voxtf4eh5kz@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16sched: Fix up scheduler syscall LTP failsPeter Zijlstra1-3/+11
Wu reported LTP failures: > ltp.sched_setparam02.1.TFAIL > ltp.sched_setparam02.2.TFAIL > ltp.sched_setparam02.3.TFAIL > ltp.sched_setparam03.1.TFAIL There were 2 things wrong; firstly __setscheduler() failed on sched_setparam()'s policy = -1, fix that by reading from p->policy in that case. Secondly, getparam() (and getattr()) would still report !0 sched_priority for !FIFO/RR tasks after having been such. So unconditionally set p->rt_priority. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Dario Faggioli <raistlin@linux.it> Fixes: d50dde5a10f3 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI") Link: http://lkml.kernel.org/r/20140115153320.GH31570@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16sched: Preserve the nice level over sched_setscheduler() and ↵Peter Zijlstra1-2/+4
sched_setparam() calls Previously sched_setscheduler() and sched_setparam() would not affect the nice value of a task, restore this behaviour. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: raistlin@linux.it Cc: juri.lelli@gmail.com Cc: Michael wang <wangyun@linux.vnet.ibm.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Fixes: d50dde5a10f3 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI") Link: http://lkml.kernel.org/r/20140115113015.GB31570@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16sched/core: Fix htmldocs warningsJuri Lelli1-2/+2
Fengguang Wu's kbuild test robot reported the following new htmldocs warnings: >>> Warning(kernel/sched/core.c:3380): No description found for parameter 'uattr' >>> Warning(kernel/sched/core.c:3380): Excess function parameter 'attr' description in 'sys_sched_setattr' >>> Warning(kernel/sched/core.c:3520): No description found for parameter 'uattr' >>> Warning(kernel/sched/core.c:3520): Excess function parameter 'attr' description in 'sys_sched_getattr' The second argument to sys_sched_{setattr,getattr}() is named uattr (not attr). Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Dario Faggioli <raistlin@linux.it> Fixes: d50dde5a10f3 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI") Link: http://lkml.kernel.org/r/52D5552D.5000102@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16sched/deadline: No need to check p if dl_se is validJuri Lelli1-2/+1
Dan Carpenter reported new 'Smatch' warnings: > tree: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched/core > head: 130816ce4d5f69167324f7272e70aa3d641677c6 > commit: 1baca4ce16b8cc7d4f50be1f7914799af30a2861 [17/50] sched/deadline: Add SCHED_DEADLINE SMP-related data structures & logic > > kernel/sched/deadline.c:937 pick_next_task_dl() warn: variable dereferenced before check 'p' (see line 934) BUG_ON() already fires if pick_next_dl_entity() doesn't return a valid dl_se. No need to check if p is valid afterward. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Fixes: 1baca4ce16b8 ("sched/deadline: Add SCHED_DEADLINE SMP-related data structures & logic") Link: http://lkml.kernel.org/r/52D54E25.6060100@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16sched/deadline: Remove unused variablesPeter Zijlstra1-11/+0
fix these new sparse warnings: >> kernel/sched/core.c:305:14: sparse: symbol 'sysctl_sched_dl_period' was not declared. Should it be static? >> kernel/sched/core.c:306:5: sparse: symbol 'sysctl_sched_dl_runtime' was not declared. Should it be static? Better still, they're completely unused so remove them. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@gmail.com> Link: http://lkml.kernel.org/n/tip-ke0shkG7vMnzmcdqhhiymyem@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16sched/deadline: Fix sparse static warningsFengguang Wu1-3/+3
new sparse warnings: >> kernel/sched/cpudeadline.c:38:6: sparse: symbol 'cpudl_exchange' was not declared. Should it be static? >> kernel/sched/cpudeadline.c:46:6: sparse: symbol 'cpudl_heapify' was not declared. Should it be static? >> kernel/sched/cpudeadline.c:71:6: sparse: symbol 'cpudl_change_key' was not declared. Should it be static? >> kernel/sched/cpudeadline.c:195:15: sparse: memset with byte count of 163928 Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@gmail.com> Fixes: 6bfd6d72f51c ("sched/deadline: speed up SCHED_DEADLINE pushes with a push-heap") Link: http://lkml.kernel.org/r/52d47f8c.EYJsA5+mELPBk4t6\%fengguang.wu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-16Merge branches 'sched-urgent-for-linus' and 'timers-urgent-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler and timer fixes from Ingo Molnar: "Contains a fix for a scheduler bug that manifested itself as a 3D performance regression and a crash fix for the ARM Cadence TTC clock driver" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Calculate effective load even if local weight is 0 * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource: cadence_ttc: Fix mutex taken inside interrupt context
2014-01-13sched/preempt: Fix up missed PREEMPT_NEED_RESCHED foldingPeter Zijlstra2-9/+11
With various drivers wanting to inject idle time; we get people calling idle routines outside of the idle loop proper. Therefore we need to be extra careful about not missing TIF_NEED_RESCHED -> PREEMPT_NEED_RESCHED propagations. While looking at this, I also realized there's a small window in the existing idle loop where we can miss TIF_NEED_RESCHED; when it hits right after the tif_need_resched() test at the end of the loop but right before the need_resched() test at the start of the loop. So move preempt_fold_need_resched() out of the loop where we're guaranteed to have TIF_NEED_RESCHED set. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-x9jgh45oeayzajz2mjt0y7d6@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/preempt, locking: Rework local_bh_{dis,en}able()Peter Zijlstra1-29/+6
Currently local_bh_disable() is out-of-line for no apparent reason. So inline it to save a few cycles on call/return nonsense, the function body is a single add on x86 (a few loads and store extra on load/store archs). Also expose two new local_bh functions: __local_bh_{dis,en}able_ip(unsigned long ip, unsigned int cnt); Which implement the actual local_bh_{dis,en}able() behaviour. The next patch uses the exposed @cnt argument to optimize bh lock functions. With build fixes from Jacob Pan. Cc: rjw@rjwysocki.net Cc: rui.zhang@intel.com Cc: jacob.jun.pan@linux.intel.com Cc: Mike Galbraith <bitbucket@online.de> Cc: hpa@zytor.com Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: lenb@kernel.org Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131119151338.GF3694@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/clock: Fix up clear_sched_clock_stable()Peter Zijlstra1-1/+12
The below tells us the static_key conversion has a problem; since the exact point of clearing that flag isn't too important, delay the flip and use a workqueue to process it. [ ] TSC synchronization [CPU#0 -> CPU#22]: [ ] Measured 8 cycles TSC warp between CPUs, turning off TSC clock. [ ] [ ] ====================================================== [ ] [ INFO: possible circular locking dependency detected ] [ ] 3.13.0-rc3-01745-g848b0d0322cb-dirty #637 Not tainted [ ] ------------------------------------------------------- [ ] swapper/0/1 is trying to acquire lock: [ ] (jump_label_mutex){+.+...}, at: [<ffffffff8115a637>] jump_label_lock+0x17/0x20 [ ] [ ] but task is already holding lock: [ ] (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8109408b>] cpu_hotplug_begin+0x2b/0x60 [ ] [ ] which lock already depends on the new lock. [ ] [ ] [ ] the existing dependency chain (in reverse order) is: [ ] [ ] -> #1 (cpu_hotplug.lock){+.+.+.}: [ ] [<ffffffff810def00>] lock_acquire+0x90/0x130 [ ] [<ffffffff81661f83>] mutex_lock_nested+0x63/0x3e0 [ ] [<ffffffff81093fdc>] get_online_cpus+0x3c/0x60 [ ] [<ffffffff8104cc67>] arch_jump_label_transform+0x37/0x130 [ ] [<ffffffff8115a3cf>] __jump_label_update+0x5f/0x80 [ ] [<ffffffff8115a48d>] jump_label_update+0x9d/0xb0 [ ] [<ffffffff8115aa6d>] static_key_slow_inc+0x9d/0xb0 [ ] [<ffffffff810c0f65>] sched_feat_set+0xf5/0x100 [ ] [<ffffffff810c5bdc>] set_numabalancing_state+0x2c/0x30 [ ] [<ffffffff81d12f3d>] numa_policy_init+0x1af/0x1b7 [ ] [<ffffffff81cebdf4>] start_kernel+0x35d/0x41f [ ] [<ffffffff81ceb5a5>] x86_64_start_reservations+0x2a/0x2c [ ] [<ffffffff81ceb6a2>] x86_64_start_kernel+0xfb/0xfe [ ] [ ] -> #0 (jump_label_mutex){+.+...}: [ ] [<ffffffff810de141>] __lock_acquire+0x1701/0x1eb0 [ ] [<ffffffff810def00>] lock_acquire+0x90/0x130 [ ] [<ffffffff81661f83>] mutex_lock_nested+0x63/0x3e0 [ ] [<ffffffff8115a637>] jump_label_lock+0x17/0x20 [ ] [<ffffffff8115aa3b>] static_key_slow_inc+0x6b/0xb0 [ ] [<ffffffff810ca775>] clear_sched_clock_stable+0x15/0x20 [ ] [<ffffffff810503b3>] mark_tsc_unstable+0x23/0x70 [ ] [<ffffffff810772cb>] check_tsc_sync_source+0x14b/0x150 [ ] [<ffffffff81076612>] native_cpu_up+0x3a2/0x890 [ ] [<ffffffff810941cb>] _cpu_up+0xdb/0x160 [ ] [<ffffffff810942c9>] cpu_up+0x79/0x90 [ ] [<ffffffff81d0af6b>] smp_init+0x60/0x8c [ ] [<ffffffff81cebf42>] kernel_init_freeable+0x8c/0x197 [ ] [<ffffffff8164e32e>] kernel_init+0xe/0x130 [ ] [<ffffffff8166beec>] ret_from_fork+0x7c/0xb0 [ ] [ ] other info that might help us debug this: [ ] [ ] Possible unsafe locking scenario: [ ] [ ] CPU0 CPU1 [ ] ---- ---- [ ] lock(cpu_hotplug.lock); [ ] lock(jump_label_mutex); [ ] lock(cpu_hotplug.lock); [ ] lock(jump_label_mutex); [ ] [ ] *** DEADLOCK *** [ ] [ ] 2 locks held by swapper/0/1: [ ] #0: (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff81094037>] cpu_maps_update_begin+0x17/0x20 [ ] #1: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8109408b>] cpu_hotplug_begin+0x2b/0x60 [ ] [ ] stack backtrace: [ ] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-rc3-01745-g848b0d0322cb-dirty #637 [ ] Hardware name: Supermicro X8DTN/X8DTN, BIOS 4.6.3 01/08/2010 [ ] ffffffff82c9c270 ffff880236843bb8 ffffffff8165c5f5 ffffffff82c9c270 [ ] ffff880236843bf8 ffffffff81658c02 ffff880236843c80 ffff8802368586a0 [ ] ffff880236858678 0000000000000001 0000000000000002 ffff880236858000 [ ] Call Trace: [ ] [<ffffffff8165c5f5>] dump_stack+0x4e/0x7a [ ] [<ffffffff81658c02>] print_circular_bug+0x1f9/0x207 [ ] [<ffffffff810de141>] __lock_acquire+0x1701/0x1eb0 [ ] [<ffffffff816680ff>] ? __atomic_notifier_call_chain+0x8f/0xb0 [ ] [<ffffffff810def00>] lock_acquire+0x90/0x130 [ ] [<ffffffff8115a637>] ? jump_label_lock+0x17/0x20 [ ] [<ffffffff8115a637>] ? jump_label_lock+0x17/0x20 [ ] [<ffffffff81661f83>] mutex_lock_nested+0x63/0x3e0 [ ] [<ffffffff8115a637>] ? jump_label_lock+0x17/0x20 [ ] [<ffffffff8115a637>] jump_label_lock+0x17/0x20 [ ] [<ffffffff8115aa3b>] static_key_slow_inc+0x6b/0xb0 [ ] [<ffffffff810ca775>] clear_sched_clock_stable+0x15/0x20 [ ] [<ffffffff810503b3>] mark_tsc_unstable+0x23/0x70 [ ] [<ffffffff810772cb>] check_tsc_sync_source+0x14b/0x150 [ ] [<ffffffff81076612>] native_cpu_up+0x3a2/0x890 [ ] [<ffffffff810941cb>] _cpu_up+0xdb/0x160 [ ] [<ffffffff810942c9>] cpu_up+0x79/0x90 [ ] [<ffffffff81d0af6b>] smp_init+0x60/0x8c [ ] [<ffffffff81cebf42>] kernel_init_freeable+0x8c/0x197 [ ] [<ffffffff8164e320>] ? rest_init+0xd0/0xd0 [ ] [<ffffffff8164e32e>] kernel_init+0xe/0x130 [ ] [<ffffffff8166beec>] ret_from_fork+0x7c/0xb0 [ ] [<ffffffff8164e320>] ? rest_init+0xd0/0xd0 [ ] ------------[ cut here ]------------ [ ] WARNING: CPU: 0 PID: 1 at /usr/src/linux-2.6/kernel/smp.c:374 smp_call_function_many+0xad/0x300() [ ] Modules linked in: [ ] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-rc3-01745-g848b0d0322cb-dirty #637 [ ] Hardware name: Supermicro X8DTN/X8DTN, BIOS 4.6.3 01/08/2010 [ ] 0000000000000009 ffff880236843be0 ffffffff8165c5f5 0000000000000000 [ ] ffff880236843c18 ffffffff81093d8c 0000000000000000 0000000000000000 [ ] ffffffff81ccd1a0 ffffffff810ca951 0000000000000000 ffff880236843c28 [ ] Call Trace: [ ] [<ffffffff8165c5f5>] dump_stack+0x4e/0x7a [ ] [<ffffffff81093d8c>] warn_slowpath_common+0x8c/0xc0 [ ] [<ffffffff810ca951>] ? sched_clock_tick+0x1/0xa0 [ ] [<ffffffff81093dda>] warn_slowpath_null+0x1a/0x20 [ ] [<ffffffff8110b72d>] smp_call_function_many+0xad/0x300 [ ] [<ffffffff8104f200>] ? arch_unregister_cpu+0x30/0x30 [ ] [<ffffffff8104f200>] ? arch_unregister_cpu+0x30/0x30 [ ] [<ffffffff810ca951>] ? sched_clock_tick+0x1/0xa0 [ ] [<ffffffff8110ba96>] smp_call_function+0x46/0x80 [ ] [<ffffffff8104f200>] ? arch_unregister_cpu+0x30/0x30 [ ] [<ffffffff8110bb3c>] on_each_cpu+0x3c/0xa0 [ ] [<ffffffff810ca950>] ? sched_clock_idle_sleep_event+0x20/0x20 [ ] [<ffffffff810ca951>] ? sched_clock_tick+0x1/0xa0 [ ] [<ffffffff8104f964>] text_poke_bp+0x64/0xd0 [ ] [<ffffffff810ca950>] ? sched_clock_idle_sleep_event+0x20/0x20 [ ] [<ffffffff8104ccde>] arch_jump_label_transform+0xae/0x130 [ ] [<ffffffff8115a3cf>] __jump_label_update+0x5f/0x80 [ ] [<ffffffff8115a48d>] jump_label_update+0x9d/0xb0 [ ] [<ffffffff8115aa6d>] static_key_slow_inc+0x9d/0xb0 [ ] [<ffffffff810ca775>] clear_sched_clock_stable+0x15/0x20 [ ] [<ffffffff810503b3>] mark_tsc_unstable+0x23/0x70 [ ] [<ffffffff810772cb>] check_tsc_sync_source+0x14b/0x150 [ ] [<ffffffff81076612>] native_cpu_up+0x3a2/0x890 [ ] [<ffffffff810941cb>] _cpu_up+0xdb/0x160 [ ] [<ffffffff810942c9>] cpu_up+0x79/0x90 [ ] [<ffffffff81d0af6b>] smp_init+0x60/0x8c [ ] [<ffffffff81cebf42>] kernel_init_freeable+0x8c/0x197 [ ] [<ffffffff8164e320>] ? rest_init+0xd0/0xd0 [ ] [<ffffffff8164e32e>] kernel_init+0xe/0x130 [ ] [<ffffffff8166beec>] ret_from_fork+0x7c/0xb0 [ ] [<ffffffff8164e320>] ? rest_init+0xd0/0xd0 [ ] ---[ end trace 6ff1df5620c49d26 ]--- [ ] tsc: Marking TSC unstable due to check_tsc_sync_source failed Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-v55fgqj3nnyqnngmvuu8ep6h@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/clock, x86: Use a static_key for sched_clock_stablePeter Zijlstra4-10/+37
In order to avoid the runtime condition and variable load turn sched_clock_stable into a static_key. Also provide a shorter implementation of local_clock() and cpu_clock(int) when sched_clock_stable==1. MAINLINE PRE POST sched_clock_stable: 1 1 1 (cold) sched_clock: 329841 221876 215295 (cold) local_clock: 301773 234692 220773 (warm) sched_clock: 38375 25602 25659 (warm) local_clock: 100371 33265 27242 (warm) rdtsc: 27340 24214 24208 sched_clock_stable: 0 0 0 (cold) sched_clock: 382634 235941 237019 (cold) local_clock: 396890 297017 294819 (warm) sched_clock: 38194 25233 25609 (warm) local_clock: 143452 71234 71232 (warm) rdtsc: 27345 24245 24243 Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-eummbdechzz37mwmpags1gjr@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/clock: Remove local_irq_disable() from the clocksPeter Zijlstra1-28/+6
Now that x86 no longer requires IRQs disabled for sched_clock() and ia64 never had this requirement (it doesn't seem to do cpufreq at all), we can remove the requirement of disabling IRQs. MAINLINE PRE POST sched_clock_stable: 1 1 1 (cold) sched_clock: 329841 257223 221876 (cold) local_clock: 301773 309889 234692 (warm) sched_clock: 38375 25280 25602 (warm) local_clock: 100371 85268 33265 (warm) rdtsc: 27340 24247 24214 sched_clock_stable: 0 0 0 (cold) sched_clock: 382634 301224 235941 (cold) local_clock: 396890 399870 297017 (warm) sched_clock: 38194 25630 25233 (warm) local_clock: 143452 129629 71234 (warm) rdtsc: 27345 24307 24245 Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-36e5kohiasnr106d077mgubp@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13locking: Optimize lock_bh functionsPeter Zijlstra1-2/+2
Currently all _bh_ lock functions do two preempt_count operations: local_bh_disable(); preempt_disable(); and for the unlock: preempt_enable_no_resched(); local_bh_enable(); Since its a waste of perfectly good cycles to modify the same variable twice when you can do it in one go; use the new __local_bh_{dis,en}able_ip() functions that allow us to provide a preempt_count value to add/sub. So define SOFTIRQ_LOCK_OFFSET as the offset a _bh_ lock needs to add/sub to be done in one go. As a bonus it gets rid of the preempt_enable_no_resched() usage. This reduces a 1000 loops of: spin_lock_bh(&bh_lock); spin_unlock_bh(&bh_lock); from 53596 cycles to 51995 cycles. I didn't do enough measurements to say for absolute sure that the result is significant but the the few runs I did for each suggest it is so. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: jacob.jun.pan@linux.intel.com Cc: Mike Galbraith <bitbucket@online.de> Cc: hpa@zytor.com Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: lenb@kernel.org Cc: rjw@rjwysocki.net Cc: rui.zhang@intel.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20131119151338.GF3694@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched: Factor out the on_null_domain() checks in trigger_load_balance()Daniel Lezcano1-3/+5
The test on_null_domain is done twice in the trigger_load_balance function. Move the test at the begin of the function, so there is only one check. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389008085-9069-9-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched: Pass 'struct rq' to nohz_idle_balance()Daniel Lezcano1-6/+5
The cpu information is stored in the struct rq. Pass the struct rq to nohz_idle_balance, so all the functions called in run_rebalance_domains have the same parameters and the 'this_cpu' variable becomes pointless. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> [ Added !SMP build fix. ] Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389008085-9069-8-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched: Pass 'struct rq' to rebalance_domains()Daniel Lezcano1-4/+4
The cpu information is stored in the struct rq and the caller of the rebalance_domains function pass the cpu to retrieve the struct rq but it already has the struct rq info. Replace the cpu parameter with the struct rq. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389008085-9069-7-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched: Remove unused parameter from nohz_balancer_kick()Daniel Lezcano1-4/+2
The cpu parameter is no longer needed in nohz_balancer_kick, let's remove the parameter. Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389008085-9069-6-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched: Remove unused parameter from find_new_ilb()Daniel Lezcano1-2/+2
The 'call_cpu' is never used in the function. Remove it. Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389008085-9069-5-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched: Pass 'struct rq' to on_null_domain()Daniel Lezcano1-4/+4
The on_null_domain() function is getting the cpu to retrieve the struct rq associated with it. Pass 'struct rq' directly to the function as the caller already has the info. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389008085-9069-4-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched: Reduce nohz_kick_needed() parametersDaniel Lezcano1-4/+4
The cpu information is already stored in the struct rq, so no need to pass it as parameter to the nohz_kick_needed function. The caller of this function just called idle_cpu() before to fill the rq->idle_balance field. Use rq->cpu and rq->idle_balance. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389008085-9069-3-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched: Reduce trigger_load_balance() parametersDaniel Lezcano3-3/+5
The cpu information is already stored in the struct rq, so no need to pass it as parameter to the trigger_load_balance function. Cc: linaro-kernel@lists.linaro.org Cc: preeti.lkml@gmail.com Cc: mingo@redhat.com Cc: peterz@infradead.org Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1389008085-9069-2-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: Fix hotplug admission controlPeter Zijlstra1-51/+32
The current hotplug admission control is broken because: CPU_DYING -> migration_call() -> migrate_tasks() -> __migrate_task() cannot fail and hard assumes it _will_ move all tasks off of the dying cpu, failing this will break hotplug. The much simpler solution is a DOWN_PREPARE handler that fails when removing one CPU gets us below the total allocated bandwidth. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131220171343.GL2480@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: Remove the sysctl_sched_dl knobsPeter Zijlstra4-221/+97
Remove the deadline specific sysctls for now. The problem with them is that the interaction with the exisiting rt knobs is nearly impossible to get right. The current (as per before this patch) situation is that the rt and dl bandwidth is completely separate and we enforce rt+dl < 100%. This is undesirable because this means that the rt default of 95% leaves us hardly any room, even though dl tasks are saver than rt tasks. Another proposed solution was (a discarted patch) to have the dl bandwidth be a fraction of the rt bandwidth. This is highly confusing imo. Furthermore neither proposal is consistent with the situation we actually want; which is rt tasks ran from a dl server. In which case the rt bandwidth is a direct subset of dl. So whichever way we go, the introduction of dl controls at this point is painful. Therefore remove them and instead share the rt budget. This means that for now the rt knobs are used for dl admission control and the dl runtime is accounted against the rt runtime. I realise that this isn't entirely desirable either; but whatever we do we appear to need to change the interface later, so better have a small interface for now. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-zpyqbqds1r0vyxtxza1e7rdc@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: Fix up the smp-affinity mask testsPeter Zijlstra1-19/+9
For now deadline tasks are not allowed to set smp affinity; however the current tests are wrong, cure this. The test in __sched_setscheduler() also uses an on-stack cpumask_t which is a no-no. Change both tests to use cpumask_subset() such that we test the root domain span to be a subset of the cpus_allowed mask. This way we're sure the tasks can always run on all CPUs they can be balanced over, and have no effective affinity constraints. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-fyqtb1lapxca3lhsxv9cumdc@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: speed up SCHED_DEADLINE pushes with a push-heapJuri Lelli6-40/+269
Data from tests confirmed that the original active load balancing logic didn't scale neither in the number of CPU nor in the number of tasks (as sched_rt does). Here we provide a global data structure to keep track of deadlines of the running tasks in the system. The structure is composed by a bitmask showing the free CPUs and a max-heap, needed when the system is heavily loaded. The implementation and concurrent access scheme are kept simple by design. However, our measurements show that we can compete with sched_rt on large multi-CPUs machines [1]. Only the push path is addressed, the extension to use this structure also for pull decisions is straightforward. However, we are currently evaluating different (in order to decrease/avoid contention) data structures to solve possibly both problems. We are also going to re-run tests considering recent changes inside cpupri [2]. [1] http://retis.sssup.it/~jlelli/papers/Ospert11Lelli.pdf [2] http://www.spinics.net/lists/linux-rt-users/msg06778.html Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-14-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: Add bandwidth management for SCHED_DEADLINE tasksDario Faggioli4-36/+541
In order of deadline scheduling to be effective and useful, it is important that some method of having the allocation of the available CPU bandwidth to tasks and task groups under control. This is usually called "admission control" and if it is not performed at all, no guarantee can be given on the actual scheduling of the -deadline tasks. Since when RT-throttling has been introduced each task group have a bandwidth associated to itself, calculated as a certain amount of runtime over a period. Moreover, to make it possible to manipulate such bandwidth, readable/writable controls have been added to both procfs (for system wide settings) and cgroupfs (for per-group settings). Therefore, the same interface is being used for controlling the bandwidth distrubution to -deadline tasks and task groups, i.e., new controls but with similar names, equivalent meaning and with the same usage paradigm are added. However, more discussion is needed in order to figure out how we want to manage SCHED_DEADLINE bandwidth at the task group level. Therefore, this patch adds a less sophisticated, but actually very sensible, mechanism to ensure that a certain utilization cap is not overcome per each root_domain (the single rq for !SMP configurations). Another main difference between deadline bandwidth management and RT-throttling is that -deadline tasks have bandwidth on their own (while -rt ones doesn't!), and thus we don't need an higher level throttling mechanism to enforce the desired bandwidth. This patch, therefore: - adds system wide deadline bandwidth management by means of: * /proc/sys/kernel/sched_dl_runtime_us, * /proc/sys/kernel/sched_dl_period_us, that determine (i.e., runtime / period) the total bandwidth available on each CPU of each root_domain for -deadline tasks; - couples the RT and deadline bandwidth management, i.e., enforces that the sum of how much bandwidth is being devoted to -rt -deadline tasks to stay below 100%. This means that, for a root_domain comprising M CPUs, -deadline tasks can be created until the sum of their bandwidths stay below: M * (sched_dl_runtime_us / sched_dl_period_us) It is also possible to disable this bandwidth management logic, and be thus free of oversubscribing the system up to any arbitrary level. Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-12-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: Add SCHED_DEADLINE inheritance logicDario Faggioli7-53/+122
Some method to deal with rt-mutexes and make sched_dl interact with the current PI-coded is needed, raising all but trivial issues, that needs (according to us) to be solved with some restructuring of the pi-code (i.e., going toward a proxy execution-ish implementation). This is under development, in the meanwhile, as a temporary solution, what this commits does is: - ensure a pi-lock owner with waiters is never throttled down. Instead, when it runs out of runtime, it immediately gets replenished and it's deadline is postponed; - the scheduling parameters (relative deadline and default runtime) used for that replenishments --during the whole period it holds the pi-lock-- are the ones of the waiting task with earliest deadline. Acting this way, we provide some kind of boosting to the lock-owner, still by using the existing (actually, slightly modified by the previous commit) pi-architecture. We would stress the fact that this is only a surely needed, all but clean solution to the problem. In the end it's only a way to re-start discussion within the community. So, as always, comments, ideas, rants, etc.. are welcome! :-) Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> [ Added !RT_MUTEXES build fix. ] Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-11-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13rtmutex: Turn the plist into an rb-treePeter Zijlstra6-52/+138
Turn the pi-chains from plist to rb-tree, in the rt_mutex code, and provide a proper comparison function for -deadline and -priority tasks. This is done mainly because: - classical prio field of the plist is just an int, which might not be enough for representing a deadline; - manipulating such a list would become O(nr_deadline_tasks), which might be to much, as the number of -deadline task increases. Therefore, an rb-tree is used, and tasks are queued in it according to the following logic: - among two -priority (i.e., SCHED_BATCH/OTHER/RR/FIFO) tasks, the one with the higher (lower, actually!) prio wins; - among a -priority and a -deadline task, the latter always wins; - among two -deadline tasks, the one with the earliest deadline wins. Queueing and dequeueing functions are changed accordingly, for both the list of a task's pi-waiters and the list of tasks blocked on a pi-lock. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-again-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-10-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: Add latency tracing for SCHED_DEADLINE tasksDario Faggioli2-18/+79
It is very likely that systems that wants/needs to use the new SCHED_DEADLINE policy also want to have the scheduling latency of the -deadline tasks under control. For this reason a new version of the scheduling wakeup latency, called "wakeup_dl", is introduced. As a consequence of applying this patch there will be three wakeup latency tracer: * "wakeup", that deals with all tasks in the system; * "wakeup_rt", that deals with -rt and -deadline tasks only; * "wakeup_dl", that deals with -deadline tasks only. Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-9-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: Add period support for SCHED_DEADLINE tasksHarald Gustafsson2-5/+15
Make it possible to specify a period (different or equal than deadline) for -deadline tasks. Relative deadlines (D_i) are used on task arrivals to generate new scheduling (absolute) deadlines as "d = t + D_i", and periods (P_i) to postpone the scheduling deadlines as "d = d + P_i" when the budget is zero. This is in general useful to model (and schedule) tasks that have slow activation rates (long periods), but have to be scheduled soon once activated (short deadlines). Signed-off-by: Harald Gustafsson <harald.gustafsson@ericsson.com> Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-7-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: Add SCHED_DEADLINE avg_update accountingDario Faggioli1-0/+2
Make the core scheduler and load balancer aware of the load produced by -deadline tasks, by updating the moving average like for sched_rt. Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-6-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: Add SCHED_DEADLINE SMP-related data structures & logicJuri Lelli4-17/+962
Introduces data structures relevant for implementing dynamic migration of -deadline tasks and the logic for checking if runqueues are overloaded with -deadline tasks and for choosing where a task should migrate, when it is the case. Adds also dynamic migrations to SCHED_DEADLINE, so that tasks can be moved among CPUs when necessary. It is also possible to bind a task to a (set of) CPU(s), thus restricting its capability of migrating, or forbidding migrations at all. The very same approach used in sched_rt is utilised: - -deadline tasks are kept into CPU-specific runqueues, - -deadline tasks are migrated among runqueues to achieve the following: * on an M-CPU system the M earliest deadline ready tasks are always running; * affinity/cpusets settings of all the -deadline tasks is always respected. Therefore, this very special form of "load balancing" is done with an active method, i.e., the scheduler pushes or pulls tasks between runqueues when they are woken up and/or (de)scheduled. IOW, every time a preemption occurs, the descheduled task might be sent to some other CPU (depending on its deadline) to continue executing (push). On the other hand, every time a CPU becomes idle, it might pull the second earliest deadline ready task from some other CPU. To enforce this, a pull operation is always attempted before taking any scheduling decision (pre_schedule()), as well as a push one after each scheduling decision (post_schedule()). In addition, when a task arrives or wakes up, the best CPU where to resume it is selected taking into account its affinity mask, the system topology, but also its deadline. E.g., from the scheduling point of view, the best CPU where to wake up (and also where to push) a task is the one which is running the task with the latest deadline among the M executing ones. In order to facilitate these decisions, per-runqueue "caching" of the deadlines of the currently running and of the first ready task is used. Queued but not running tasks are also parked in another rb-tree to speed-up pushes. Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-5-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched/deadline: Add SCHED_DEADLINE structures & implementationDario Faggioli7-19/+812
Introduces the data structures, constants and symbols needed for SCHED_DEADLINE implementation. Core data structure of SCHED_DEADLINE are defined, along with their initializers. Hooks for checking if a task belong to the new policy are also added where they are needed. Adds a scheduling class, in sched/dl.c and a new policy called SCHED_DEADLINE. It is an implementation of the Earliest Deadline First (EDF) scheduling algorithm, augmented with a mechanism (called Constant Bandwidth Server, CBS) that makes it possible to isolate the behaviour of tasks between each other. The typical -deadline task will be made up of a computation phase (instance) which is activated on a periodic or sporadic fashion. The expected (maximum) duration of such computation is called the task's runtime; the time interval by which each instance need to be completed is called the task's relative deadline. The task's absolute deadline is dynamically calculated as the time instant a task (better, an instance) activates plus the relative deadline. The EDF algorithms selects the task with the smallest absolute deadline as the one to be executed first, while the CBS ensures each task to run for at most its runtime every (relative) deadline length time interval, avoiding any interference between different tasks (bandwidth isolation). Thanks to this feature, also tasks that do not strictly comply with the computational model sketched above can effectively use the new policy. To summarize, this patch: - introduces the data structures, constants and symbols needed; - implements the core logic of the scheduling algorithm in the new scheduling class file; - provides all the glue code between the new scheduling class and the core scheduler and refines the interactions between sched/dl and the other existing scheduling classes. Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com> Signed-off-by: Fabio Checconi <fchecconi@gmail.com> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-4-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13sched: Add new scheduler syscalls to support an extended scheduling ↵Dario Faggioli2-23/+249
parameters ABI Add the syscalls needed for supporting scheduling algorithms with extended scheduling parameters (e.g., SCHED_DEADLINE). In general, it makes possible to specify a periodic/sporadic task, that executes for a given amount of runtime at each instance, and is scheduled according to the urgency of their own timing constraints, i.e.: - a (maximum/typical) instance execution time, - a minimum interval between consecutive instances, - a time constraint by which each instance must be completed. Thus, both the data structure that holds the scheduling parameters of the tasks and the system calls dealing with it must be extended. Unfortunately, modifying the existing struct sched_param would break the ABI and result in potentially serious compatibility issues with legacy binaries. For these reasons, this patch: - defines the new struct sched_attr, containing all the fields that are necessary for specifying a task in the computational model described above; - defines and implements the new scheduling related syscalls that manipulate it, i.e., sched_setattr() and sched_getattr(). Syscalls are introduced for x86 (32 and 64 bits) and ARM only, as a proof of concept and for developing and testing purposes. Making them available on other architectures is straightforward. Since no "user" for these new parameters is introduced in this patch, the implementation of the new system calls is just identical to their already existing counterpart. Future patches that implement scheduling policies able to exploit the new data structure must also take care of modifying the sched_*attr() calls accordingly with their own purposes. Signed-off-by: Dario Faggioli <raistlin@linux.it> [ Rewrote to use sched_attr. ] Signed-off-by: Juri Lelli <juri.lelli@gmail.com> [ Removed sched_setscheduler2() for now. ] Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1383831828-15501-3-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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