linux/kernel
Joel Fernandes (Google) c3bc8fd637 tracing: Centralize preemptirq tracepoints and unify their usage
This patch detaches the preemptirq tracepoints from the tracers and
keeps it separate.

Advantages:
* Lockdep and irqsoff event can now run in parallel since they no longer
have their own calls.

* This unifies the usecase of adding hooks to an irqsoff and irqson
event, and a preemptoff and preempton event.
  3 users of the events exist:
  - Lockdep
  - irqsoff and preemptoff tracers
  - irqs and preempt trace events

The unification cleans up several ifdefs and makes the code in preempt
tracer and irqsoff tracers simpler. It gets rid of all the horrific
ifdeferry around PROVE_LOCKING and makes configuration of the different
users of the tracepoints more easy and understandable. It also gets rid
of the time_* function calls from the lockdep hooks used to call into
the preemptirq tracer which is not needed anymore. The negative delta in
lines of code in this patch is quite large too.

In the patch we introduce a new CONFIG option PREEMPTIRQ_TRACEPOINTS
as a single point for registering probes onto the tracepoints. With
this,
the web of config options for preempt/irq toggle tracepoints and its
users becomes:

 PREEMPT_TRACER   PREEMPTIRQ_EVENTS  IRQSOFF_TRACER PROVE_LOCKING
       |                 |     \         |           |
       \    (selects)    /      \        \ (selects) /
      TRACE_PREEMPT_TOGGLE       ----> TRACE_IRQFLAGS
                      \                  /
                       \ (depends on)   /
                     PREEMPTIRQ_TRACEPOINTS

Other than the performance tests mentioned in the previous patch, I also
ran the locking API test suite. I verified that all tests cases are
passing.

I also injected issues by not registering lockdep probes onto the
tracepoints and I see failures to confirm that the probes are indeed
working.

This series + lockdep probes not registered (just to inject errors):
[    0.000000]      hard-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]      soft-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/12:FAILED|FAILED|  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/21:FAILED|FAILED|  ok  |
[    0.000000]          hard-safe-A + irqs-on/12:FAILED|FAILED|  ok  |
[    0.000000]          soft-safe-A + irqs-on/12:FAILED|FAILED|  ok  |
[    0.000000]          hard-safe-A + irqs-on/21:FAILED|FAILED|  ok  |
[    0.000000]          soft-safe-A + irqs-on/21:FAILED|FAILED|  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |

With this series + lockdep probes registered, all locking tests pass:

[    0.000000]      hard-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]      soft-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]          hard-safe-A + irqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]          soft-safe-A + irqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]          hard-safe-A + irqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]          soft-safe-A + irqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |

Link: http://lkml.kernel.org/r/20180730222423.196630-4-joel@joelfernandes.org

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-07-31 11:32:27 -04:00
..
bpf bpf: don't leave partial mangled prog in jit_subprogs error path 2018-07-12 14:00:54 -07:00
cgroup docs: Fix some broken references 2018-06-15 18:10:01 -03:00
configs kconfig: tinyconfig: remove stale stack protector fixups 2018-06-15 07:15:28 +09:00
debug treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
dma swiotlb: export swiotlb_dma_ops 2018-06-28 14:00:40 +02:00
events perf/core: Move inline keyword at the beginning of declaration 2018-06-27 09:55:58 +02:00
gcov gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT 2018-06-08 18:56:02 +09:00
irq genirq/debugfs: Add missing IRQCHIP_SUPPORTS_LEVEL_MSI debug 2018-06-22 14:22:00 +02:00
livepatch livepatch: Allow to call a custom callback when freeing shadow variables 2018-04-17 13:42:48 +02:00
locking tracing: Centralize preemptirq tracepoints and unify their usage 2018-07-31 11:32:27 -04:00
power fix a series of Documentation/ broken file name references 2018-06-15 18:10:01 -03:00
printk Printk changes for 4.18 2018-06-06 16:04:55 -07:00
rcu treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
sched tracing: Centralize preemptirq tracepoints and unify their usage 2018-07-31 11:32:27 -04:00
time Revert "tick: Prefer a lower rating device only if it's CPU local device" 2018-07-10 22:12:47 +02:00
trace tracing: Centralize preemptirq tracepoints and unify their usage 2018-07-31 11:32:27 -04:00
.gitignore
acct.c kernel/acct.c: fix the acct->needcheck check in check_free_space() 2018-01-04 16:45:09 -08:00
async.c kernel/async.c: revert "async: simplify lowest_in_progress()" 2018-02-06 18:32:44 -08:00
audit_fsnotify.c fsnotify: add fsnotify_add_inode_mark() wrappers 2018-05-18 14:58:22 +02:00
audit_tree.c fsnotify: add fsnotify_add_inode_mark() wrappers 2018-05-18 14:58:22 +02:00
audit_watch.c \n 2018-06-17 05:06:18 +09:00
audit.c audit: use inline function to get audit context 2018-05-14 17:24:18 -04:00
audit.h audit: track the owner of the command mutex ourselves 2018-02-23 11:22:22 -05:00
auditfilter.c audit: use existing session info function 2018-05-18 15:47:54 -04:00
auditsc.c audit: Fix wrong task in comparison of session ID 2018-05-21 14:27:43 -04:00
backtracetest.c
bounds.c
capability.c
compat.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 20:27:54 -07:00
configs.c
context_tracking.c
cpu_pm.c
cpu.c cpu/hotplug: Fix unused function warning 2018-03-15 20:34:40 +01:00
crash_core.c mm: split page_type out from _mapcount 2018-06-07 17:34:37 -07:00
crash_dump.c
cred.c
delayacct.c delayacct: Use raw_spinlocks 2018-04-27 14:34:51 +02:00
dma.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
elfcore.c
exec_domain.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
exit.c kernel: use kernel_wait4() instead of sys_wait4() 2018-04-02 20:14:51 +02:00
extable.c extable: Make init_kernel_text() global 2018-02-21 16:54:06 +01:00
fail_function.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
fork.c mm: make vm_area_alloc() initialize core fields 2018-07-21 15:24:03 -07:00
freezer.c
futex_compat.c
futex.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
groups.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
hung_task.c kernel/hung_task.c: show all hung tasks before panic 2018-06-07 17:34:39 -07:00
iomem.c memremap: split devm_memremap_pages() and memremap() infrastructure 2018-05-15 23:08:33 -07:00
irq_work.c irq/work: Improve the flag definitions 2018-01-08 19:43:15 +01:00
jump_label.c jump_label: Disable jump labels in __exit code 2018-03-20 08:57:17 +01:00
kallsyms.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-02-01 13:36:15 -08:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c sched/core / kcov: avoid kcov_area during task switch 2018-06-15 07:55:24 +09:00
kexec_core.c kexec: yield to scheduler when loading kimage segments 2018-06-15 07:55:24 +09:00
kexec_file.c treewide: Use array_size() in vzalloc() 2018-06-12 16:19:22 -07:00
kexec_internal.h
kexec.c kexec: call do_kexec_load() in compat syscall directly 2018-04-02 20:15:01 +02:00
kmod.c
kprobes.c kprobes: Fix random address output of blacklist file 2018-04-25 10:27:56 -04:00
ksysfs.c
kthread.c kthread, tracing: Don't expose half-written comm when creating kthreads 2018-07-26 09:59:33 -04:00
latencytop.c
Makefile dma-mapping: move all DMA mapping code to kernel/dma 2018-06-14 08:50:37 +02:00
memremap.c mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS 2018-05-22 06:59:39 -07:00
module_signing.c
module-internal.h
module.c Modules updates for v4.18 2018-06-16 07:36:39 +09:00
notifier.c
nsproxy.c
padata.c padata: add SPDX identifier 2018-01-05 18:43:00 +11:00
panic.c Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables 2018-06-14 12:21:18 +09:00
params.c kernel/params.c: downgrade warning for unsafe parameters 2018-04-11 10:28:37 -07:00
pid_namespace.c Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-04-03 19:15:32 -07:00
pid.c xarray: add the xa_lock to the radix_tree_root 2018-04-11 10:28:39 -07:00
profile.c
ptrace.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
range.c
reboot.c
relay.c kernel/relay.c: change return type to vm_fault_t 2018-06-15 07:55:24 +09:00
resource.c libnvdimm for 4.18 2018-06-08 17:21:52 -07:00
rseq.c rseq: uapi: Declare rseq_cs field as union, update includes 2018-07-10 22:18:52 +02:00
seccomp.c audit/stable-4.18 PR 20180605 2018-06-06 16:34:00 -07:00
signal.c signal: Remove no longer required irqsave/restore 2018-06-10 06:14:01 +02:00
smp.c
smpboot.c
smpboot.h
softirq.c Mark HI and TASKLET softirq synchronous 2018-07-17 11:12:43 -07:00
stacktrace.c
stop_machine.c stop_machine: Disable preemption when waking two stopper threads 2018-07-15 12:12:45 +02:00
sys_ni.c Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 10:17:09 -07:00
sys.c mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct 2018-06-07 17:34:34 -07:00
sysctl_binary.c staging: irda: remove remaining remants of irda code removal 2018-04-16 11:26:49 +02:00
sysctl.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
task_work.c locking/barriers: Convert users of lockless_dereference() to READ_ONCE() 2017-12-17 13:57:15 +01:00
taskstats.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
test_kprobes.c
torture.c rcu: Rename cond_resched_rcu_qs() to cond_resched_tasks_rcu_qs() 2018-05-15 10:27:29 -07:00
tracepoint.c tracepoint: Make rcuidle tracepoint callers use SRCU 2018-07-30 19:13:03 -04:00
tsacct.c
ucount.c headers: untangle kmemleak.h from mm.h 2018-04-05 21:36:27 -07:00
uid16.c fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers 2018-04-02 20:15:59 +02:00
uid16.h kernel: provide ksys_*() wrappers for syscalls called by kernel/uid16.c 2018-04-02 20:15:30 +02:00
umh.c umh: fix race condition 2018-06-07 16:56:28 -04:00
up.c
user_namespace.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
user-return-notifier.c
user.c efivarfs: Limit the rate for non-root to read files 2018-02-22 10:21:02 -08:00
utsname_sysctl.c
utsname.c uts: create "struct uts_namespace" from kmem_cache 2018-04-11 10:28:35 -07:00
watchdog_hld.c
watchdog.c
workqueue_internal.h workqueue: Set worker->desc to workqueue name by default 2018-05-18 08:47:13 -07:00
workqueue.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00