15 Jun, 2016
4 commits
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Signed-off-by: Eric Engestrom
Reviewed-by: Josh Triplett
Signed-off-by: Paul E. McKenney -
Signed-off-by: Paul E. McKenney
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Reported-by: Jim Roskind
Signed-off-by: Paul E. McKenney -
Reported-by: Jim Roskind
Signed-off-by: Paul E. McKenney
20 May, 2016
1 commit
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Pull Documentation updates from Jon Corbet:
"A bit busier this time around.The most interesting thing (IMO) this time around is some beginning
infrastructural work to allow documents to be written using
restructured text. Maybe someday, in a galaxy far far away, we'll be
able to eliminate the DocBook dependency and have a much better
integrated set of kernel docs. Someday.Beyond that, there's a new document on security hardening from Kees,
the movement of some sample code over to samples/, a number of
improvements to the serial docs from Geert, and the usual collection
of corrections, typo fixes, etc"* tag 'docs-for-linus' of git://git.lwn.net/linux: (55 commits)
doc: self-protection: provide initial details
serial: doc: Use port->state instead of info
serial: doc: Always refer to tty_port->mutex
Documentation: vm: Spelling s/paltform/platform/g
Documentation/memcg: update kmem limit doc as codes behavior
docproc: print a comment about autogeneration for rst output
docproc: add support for reStructuredText format via --rst option
docproc: abstract terminating lines at first space
docproc: abstract docproc directive detection
docproc: reduce unnecessary indentation
docproc: add variables for subcommand and filename
kernel-doc: use rst C domain directives and references for types
kernel-doc: produce RestructuredText output
kernel-doc: rewrite usage description, remove duplicated comments
Doc: correct the location of sysrq.c
Documentation: fix common spelling mistakes
samples: v4l: from Documentation to samples directory
samples: connector: from Documentation to samples directory
Documentation: xillybus: fix spelling mistake
Documentation: x86: fix spelling mistakes
...
28 Apr, 2016
1 commit
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This fixes several spelling mistakes in the Documentation/ tree, which
are caught by checkpatch.pl's spell checking.Signed-off-by: Kees Cook
Reviewed-by: Paul E. McKenney
Acked-by: Randy Dunlap
Signed-off-by: Jonathan Corbet
22 Apr, 2016
1 commit
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…rture.2016.04.21a' into HEAD
doc.2016.04.19a: Documentation updates
exp.2016.03.31d: Expedited grace-period updates
fixes.2016.03.31d: Miscellaneous fixes
torture.2016.004.21a Torture-test updates
20 Apr, 2016
1 commit
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This commit adds documentation for RCU's major data structures,
including rcu_state, rcu_node, rcu_data, rcu_dynticks, and rcu_head.Signed-off-by: Paul E. McKenney
01 Apr, 2016
10 commits
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Commit #cdacbe1f91264 ("rcu: Add fastpath bypassing funnel locking")
turns out to be a pessimization at high load because it forces a tree
full of tasks to wait for an expedited grace period that they probably
do not need. This commit therefore removes this optimization.Signed-off-by: Paul E. McKenney
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Although call_rcu()'s fastpath works just fine on an idle CPU,
some branches of the slowpath invoke the scheduler, which uses
RCU. Therefore, this commit emphasizes the fact that call_rcu()
must not be invoked from an idle CPU.Signed-off-by: Paul E. McKenney
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Signed-off-by: Paul E. McKenney
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This commit uses colors to obscure the quick-quiz answers, thus getting
rid of the .htmlx file. Use your mouse to select the answer in order
to see the text. Alternatively, use your favorite scripting language
to remove all occurences of "" from the file.Reported-by: Linus Torvalds
Signed-off-by: Paul E. McKenney -
This commit removes a cutesy cartoon and also a diagram that can
just as easily be represented by text.Reported-by: Linus Torvalds
Signed-off-by: Paul E. McKenney -
There is already a blanket statement about no member of RCU's API
being legal from an offline CPU, but add an explicit note where it
states that it is illegal to invoke call_rcu() from an NMI handler.Signed-off-by: Paul E. McKenney
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This commit adds a Quick Quiz whose answer explains why the compiler
code reordering enabled by CONFIG_PREEMPT=n's empty rcu_read_lock()
and rcu_read_unlock() functions does not hinder RCU's ability to figure
out which RCU read-side critical sections have completed and not.Signed-off-by: Paul E. McKenney
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Signed-off-by: Paul E. McKenney
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This commit records RCU's responsibility to avoid degrading latencies
of CPUs running tight loops within properly configured workloads,
both in kernel and in userspace.Signed-off-by: Paul E. McKenney
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In the chapter 'analogy with reader-writer locking', the sample
code uses spinlock_t in reader-writer case. Just correct it so
that we can read the document easily.Signed-off-by: Yao Dongdong
Signed-off-by: Paul E. McKenney
06 Dec, 2015
7 commits
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Because RCU-sched expedited grace periods now use IPIs and interact
with rcu_read_unlock(), it is no longer sufficient to disable preemption
across RCU read-side critical sections that acquire and hold scheduler
locks. It is now necessary to instead disable interrupts. This commit
documents this change.Signed-off-by: Paul E. McKenney
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The RCU requirements do not make it absolutely clear that the
memory-barrier requirements are not intended to replace the fundamental
requirement that all pre-existing RCU readers complete before a grace
period completes. This commit therefore pulls the memory-barrier
requirements into a separate section and explicitly calls out the
relationship between the memory-barrier requirements and the fundamental
requirement.Signed-off-by: Paul E. McKenney
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This commit adds a second option for avoiding scheduler/RCU deadlocks,
namely that preemption be disabled across the entire RCU read-side
critical section in question.Signed-off-by: Paul E. McKenney
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This commit expands on RCU's composability by comparing it to that of
transactional memory and of locking.Signed-off-by: Paul E. McKenney
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This commit adds verbiage on boot and sysfs parameters that can be
used to control RCU CPU stall warnings, both to change the timeout
and to suppress these warnings entirely.Signed-off-by: Paul E. McKenney
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This commit records RCU's guarantee that the bottom bit of the rcu_head
structure's ->next field will remain zero for callbacks posted via
call_rcu(), but not necessarily for kfree_rcu() or some
possible future call_rcu_lazy() variant that might one day be created
for energy-efficiency purposese.Signed-off-by: Paul E. McKenney
[ paulmck: Updates URLs as suggested by Josh Triplett. ] -
This commit adds RCU requirements as published in a 2015 LWN series.
Bringing these requirements in-tree allows them to be updated as changes
are discovered.Signed-off-by: Paul E. McKenney
[ paulmck: Updates to charset and URLs as suggested by Josh Triplett. ]
08 Oct, 2015
1 commit
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doc.2015.10.06a: Documentation updates.
percpu-rwsem.2015.10.06a: Optimization of per-CPU reader-writer semaphores.
torture.2015.10.06a: Torture-test updates.
07 Oct, 2015
3 commits
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This commit rids the documentation of long-obsolete torture_type options
such as rcu_sync and adds new ones such as tasks. Also add verbiage
noting the fact that rcutorture now concurrently tests the asynchrounous,
synchronous, expedited synchronous, and polling grace-period primitives.Reported-by: David Miller
Signed-off-by: Paul E. McKenney
Acked-by: David Miller
Reviewed-by: Josh Triplett -
As there is lots of misinformation and outdated information on the
Internet about nearly all topics related to the kernel, I thought it
would be best if I based my RCU code on the guidelines of the examples
in the Documentation/ tree of the latest kernel. One thing that stuck
out when reading the whatisRCU.txt document was, "interesting how we
don't need any function to dereference rcu protected pointers when doing
updates if a lock is held. I wonder how static analyzers will work with
that." Then, a few weeks later, upon discovering sparse's __rcu support,
I ran it over my code, and lo and behold, things weren't done right.
Examining other RCU usages in the kernel reveal consistent usage of
rcu_dereference_protected, passing in lockdep_is_held as the
conditional. So, this patch adds that idiom to the documentation, so
that others ahead of me won't endure the same exercise.Signed-off-by: Jason A. Donenfeld
Signed-off-by: Paul E. McKenney
Reviewed-by: Josh Triplett -
The Linux kernel outputs copious text during boot, and a slow serial
console can result in stall warnings, particularly when messages are
printed with interrupts disabled. This commit adds this to the list
of causes of RCU CPU stall warning messages.Signed-off-by: Paul E. McKenney
Reviewed-by: Josh Triplett
21 Sep, 2015
1 commit
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This commit inverts the sense of the rcu_data structure's ->passed_quiesce
field and renames it to ->cpu_no_qs. This will allow a later commit to
use an "aggregate OR" operation to test expedited as well as normal grace
periods without added overhead.Signed-off-by: Paul E. McKenney
04 Aug, 2015
2 commits
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doc.2015.07.15a: Documentation updates.
torture.2015.07.15a: Torture-test updates. -
fixes.2015.07.22a: Miscellaneous fixes.
initexp.2015.08.04a: Initialization and expedited updates.
(Single branch due to conflicts.)
23 Jul, 2015
1 commit
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This commit renames rcu_lockdep_assert() to RCU_LOCKDEP_WARN() for
consistency with the WARN() series of macros. This also requires
inverting the sense of the conditional, which this commit also does.Reported-by: Ingo Molnar
Signed-off-by: Paul E. McKenney
Reviewed-by: Ingo Molnar
18 Jul, 2015
3 commits
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In the common case, there will be only one expedited grace period in
the system at a given time, in which case it is not helpful to use
funnel locking. This commit therefore adds a fastpath that bypasses
funnel locking when the root ->exp_funnel_mutex is not held.Signed-off-by: Paul E. McKenney
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Signed-off-by: Paul E. McKenney
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The CONFIG_RCU_CPU_STALL_INFO has been default-y for a couple of
releases with no complaints, so it is time to eliminate this Kconfig
option entirely, so that the long-form RCU CPU stall warnings cannot
be disabled. This commit does just that.Signed-off-by: Paul E. McKenney
16 Jul, 2015
1 commit
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Reported-by: Mathieu Desnoyers
Signed-off-by: Paul E. McKenney
25 Jun, 2015
1 commit
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Pull documentation updates from Jonathan Corbet:
"The main thing here is Ingo's big subdirectory documenting feature
support for each architecture. Beyond that, it's the usual pile of
fixes, tweaks, and small additions"* tag 'docs-for-linus' of git://git.lwn.net/linux-2.6: (79 commits)
doc:md: fix typo in md.txt.
Documentation/mic/mpssd: don't build x86 userspace when cross compiling
Documentation/prctl: don't build tsc tests when cross compiling
Documentation/vDSO: don't build tests when cross compiling
Doc:ABI/testing: Fix typo in sysfs-bus-fcoe
Doc: Docbook: Change wikipedia's URL from http to https in scsi.tmpl
Doc: Change wikipedia's URL from http to https
Documentation/kernel-parameters: add missing pciserial to the earlyprintk
Doc:pps: Fix typo in pps.txt
kbuild : Fix documentation of INSTALL_HDR_PATH
Documentation: filesystems: updated struct file_operations documentation in vfs.txt
kbuild: edit explanation of clean-files variable
Doc: ja_JP: Fix typo in HOWTO
Move freefall program from Documentation/ to tools/
Documentation: ARM: EXYNOS: Describe boot loaders interface
Doc:nfc: Fix typo in nfc-hci.txt
vfs: Minor documentation fix
Doc: networking: txtimestamp: fix printf format warning
Documentation, intel_pstate: Improve legacy mode internal governors description
Documentation: extend use case for EXPORT_SYMBOL_GPL()
...
23 Jun, 2015
1 commit
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Recently wikipedia announced to secure access to the servers.
Now all http access re-route to https.Signed-off-by: Masanari Iida
Signed-off-by: Jonathan Corbet
28 May, 2015
1 commit
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…plug.2015.05.27a', 'init.2015.05.27a', 'tiny.2015.05.27a' and 'torture.2015.05.27a' into HEAD
array.2015.05.27a: Remove all uses of RCU-protected array indexes.
doc.2015.05.27a: Docuemntation updates.
fixes.2015.05.27a: Miscellaneous fixes.
hotplug.2015.05.27a: CPU-hotplug updates.
init.2015.05.27a: Initialization/Kconfig updates.
tiny.2015.05.27a: Updates to Tiny RCU.
torture.2015.05.27a: Torture-testing updates.