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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-08-06 14:15:47 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2020-08-06 14:15:47 +0300 |
| commit | 94fb1afb14c4f0ceb8c5508ddddac6819f662e95 (patch) | |
| tree | 4988e5769dc7482caa7f441475ae31f50bbd37ef /Documentation/locking/mutex-design.rst | |
| parent | c4735d990268399da9133b0ad445e488ece009ad (diff) | |
| parent | 47ec5303d73ea344e84f46660fff693c57641386 (diff) | |
| download | linux-94fb1afb14c4f0ceb8c5508ddddac6819f662e95.tar.xz | |
Mgerge remote-tracking branch 'torvalds/master' into perf/core
To sync headers, for instance, in this case tools/perf was ahead of
upstream till Linus merged tip/perf/core to get the
PERF_RECORD_TEXT_POKE changes:
Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'
diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'Documentation/locking/mutex-design.rst')
| -rw-r--r-- | Documentation/locking/mutex-design.rst | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/Documentation/locking/mutex-design.rst b/Documentation/locking/mutex-design.rst index 4d8236b81fa5..78540cd7f54b 100644 --- a/Documentation/locking/mutex-design.rst +++ b/Documentation/locking/mutex-design.rst @@ -18,7 +18,7 @@ as an alternative to these. This new data structure provided a number of advantages, including simpler interfaces, and at that time smaller code (see Disadvantages). -[1] http://lwn.net/Articles/164802/ +[1] https://lwn.net/Articles/164802/ Implementation -------------- @@ -28,7 +28,7 @@ and implemented in kernel/locking/mutex.c. These locks use an atomic variable (->owner) to keep track of the lock state during its lifetime. Field owner actually contains `struct task_struct *` to the current lock owner and it is therefore NULL if not currently owned. Since task_struct pointers are aligned -at at least L1_CACHE_BYTES, low bits (3) are used to store extra state (e.g., +to at least L1_CACHE_BYTES, low bits (3) are used to store extra state (e.g., if waiter list is non-empty). In its most basic form it also includes a wait-queue and a spinlock that serializes access to it. Furthermore, CONFIG_MUTEX_SPIN_ON_OWNER=y systems use a spinner MCS lock (->osq), described |