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authorMauro Carvalho Chehab <mchehab@s-opensource.com>2017-07-17 11:17:36 -0300
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2017-07-17 11:17:36 -0300
commita3db9d60a118571e696b684a6e8c692a2b064941 (patch)
treeff7bae0f79b7a2ee0bce03de4f883550200c52a9 /Documentation/irqflags-tracing.txt
parentmedia: staging: cxd2099: Activate cxd2099 buffer mode (diff)
parentLinux v4.13-rc1 (diff)
downloadlinux-dev-a3db9d60a118571e696b684a6e8c692a2b064941.tar.xz
linux-dev-a3db9d60a118571e696b684a6e8c692a2b064941.zip
Merge tag 'v4.13-rc1' into patchwork
Linux v4.13-rc1 * tag 'v4.13-rc1': (11136 commits) Linux v4.13-rc1 random: reorder READ_ONCE() in get_random_uXX random: suppress spammy warnings about unseeded randomness replace incorrect strscpy use in FORTIFY_SOURCE kmod: throttle kmod thread limit kmod: add test driver to stress test the module loader MAINTAINERS: give kmod some maintainer love xtensa: use generic fb.h fault-inject: add /proc/<pid>/fail-nth fault-inject: simplify access check for fail-nth fault-inject: make fail-nth read/write interface symmetric fault-inject: parse as natural 1-based value for fail-nth write interface fault-inject: automatically detect the number base for fail-nth write interface kernel/watchdog.c: use better pr_fmt prefix MAINTAINERS: move the befs tree to kernel.org lib/atomic64_test.c: add a test that atomic64_inc_not_zero() returns an int mm: fix overflow check in expand_upwards() ubifs: Set double hash cookie also for RENAME_EXCHANGE ubifs: Massage assert in ubifs_xattr_set() wrt. init_xattrs ubifs: Don't leak kernel memory to the MTD ...
Diffstat (limited to 'Documentation/irqflags-tracing.txt')
-rw-r--r--Documentation/irqflags-tracing.txt10
1 files changed, 6 insertions, 4 deletions
diff --git a/Documentation/irqflags-tracing.txt b/Documentation/irqflags-tracing.txt
index f6da05670e16..bdd208259fb3 100644
--- a/Documentation/irqflags-tracing.txt
+++ b/Documentation/irqflags-tracing.txt
@@ -1,8 +1,10 @@
+=======================
IRQ-flags state tracing
+=======================
-started by Ingo Molnar <mingo@redhat.com>
+:Author: started by Ingo Molnar <mingo@redhat.com>
-the "irq-flags tracing" feature "traces" hardirq and softirq state, in
+The "irq-flags tracing" feature "traces" hardirq and softirq state, in
that it gives interested subsystems an opportunity to be notified of
every hardirqs-off/hardirqs-on, softirqs-off/softirqs-on event that
happens in the kernel.
@@ -14,7 +16,7 @@ CONFIG_PROVE_RWSEM_LOCKING will be offered on an architecture - these
are locking APIs that are not used in IRQ context. (the one exception
for rwsems is worked around)
-architecture support for this is certainly not in the "trivial"
+Architecture support for this is certainly not in the "trivial"
category, because lots of lowlevel assembly code deal with irq-flags
state changes. But an architecture can be irq-flags-tracing enabled in a
rather straightforward and risk-free manner.
@@ -41,7 +43,7 @@ irq-flags-tracing support:
excluded from the irq-tracing [and lock validation] mechanism via
lockdep_off()/lockdep_on().
-in general there is no risk from having an incomplete irq-flags-tracing
+In general there is no risk from having an incomplete irq-flags-tracing
implementation in an architecture: lockdep will detect that and will
turn itself off. I.e. the lock validator will still be reliable. There
should be no crashes due to irq-tracing bugs. (except if the assembly