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Diffstat (limited to 'Documentation/RCU/Design/Requirements/Requirements.rst')
| -rw-r--r-- | Documentation/RCU/Design/Requirements/Requirements.rst | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/Documentation/RCU/Design/Requirements/Requirements.rst b/Documentation/RCU/Design/Requirements/Requirements.rst index e8c84fcc0507..d4c9a016074b 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.rst +++ b/Documentation/RCU/Design/Requirements/Requirements.rst @@ -45,7 +45,7 @@ requirements: #. `Other RCU Flavors`_ #. `Possible Future Changes`_ -This is followed by a `summary <#Summary>`__, however, the answers to +This is followed by a summary_, however, the answers to each quick quiz immediately follows the quiz. Select the big white space with your mouse to see the answer. @@ -1096,7 +1096,7 @@ memory barriers. | case, voluntary context switch) within an RCU read-side critical | | section. However, sleeping locks may be used within userspace RCU | | read-side critical sections, and also within Linux-kernel sleepable | -| RCU `(SRCU) <#Sleepable%20RCU>`__ read-side critical sections. In | +| RCU `(SRCU) <Sleepable RCU_>`__ read-side critical sections. In | | addition, the -rt patchset turns spinlocks into a sleeping locks so | | that the corresponding critical sections can be preempted, which also | | means that these sleeplockified spinlocks (but not other sleeping | @@ -1186,7 +1186,7 @@ non-preemptible (``CONFIG_PREEMPT=n``) kernels, and thus `tiny RCU <https://lkml.kernel.org/g/20090113221724.GA15307@linux.vnet.ibm.com>`__ was born. Josh Triplett has since taken over the small-memory banner with his `Linux kernel tinification <https://tiny.wiki.kernel.org/>`__ -project, which resulted in `SRCU <#Sleepable%20RCU>`__ becoming optional +project, which resulted in `SRCU <Sleepable RCU_>`__ becoming optional for those kernels not needing it. The remaining performance requirements are, for the most part, @@ -1457,8 +1457,8 @@ will vary as the value of ``HZ`` varies, and can also be changed using the relevant Kconfig options and kernel boot parameters. RCU currently does not do much sanity checking of these parameters, so please use caution when changing them. Note that these forward-progress measures -are provided only for RCU, not for `SRCU <#Sleepable%20RCU>`__ or `Tasks -RCU <#Tasks%20RCU>`__. +are provided only for RCU, not for `SRCU <Sleepable RCU_>`__ or `Tasks +RCU`_. RCU takes the following steps in ``call_rcu()`` to encourage timely invocation of callbacks when any given non-\ ``rcu_nocbs`` CPU has @@ -1477,8 +1477,8 @@ encouragement was provided: Again, these are default values when running at ``HZ=1000``, and can be overridden. Again, these forward-progress measures are provided only for -RCU, not for `SRCU <#Sleepable%20RCU>`__ or `Tasks -RCU <#Tasks%20RCU>`__. Even for RCU, callback-invocation forward +RCU, not for `SRCU <Sleepable RCU_>`__ or `Tasks +RCU`_. Even for RCU, callback-invocation forward progress for ``rcu_nocbs`` CPUs is much less well-developed, in part because workloads benefiting from ``rcu_nocbs`` CPUs tend to invoke ``call_rcu()`` relatively infrequently. If workloads emerge that need @@ -1920,7 +1920,7 @@ Hotplug CPU The Linux kernel supports CPU hotplug, which means that CPUs can come and go. It is of course illegal to use any RCU API member from an -offline CPU, with the exception of `SRCU <#Sleepable%20RCU>`__ read-side +offline CPU, with the exception of `SRCU <Sleepable RCU_>`__ read-side critical sections. This requirement was present from day one in DYNIX/ptx, but on the other hand, the Linux kernel's CPU-hotplug implementation is “interesting.” @@ -2177,7 +2177,7 @@ handles these states differently: However, RCU must be reliably informed as to whether any given CPU is currently in the idle loop, and, for ``NO_HZ_FULL``, also whether that CPU is executing in usermode, as discussed -`earlier <#Energy%20Efficiency>`__. It also requires that the +`earlier <Energy Efficiency_>`__. It also requires that the scheduling-clock interrupt be enabled when RCU needs it to be: #. If a CPU is either idle or executing in usermode, and RCU believes it @@ -2294,7 +2294,7 @@ Performance, Scalability, Response Time, and Reliability ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Expanding on the `earlier -discussion <#Performance%20and%20Scalability>`__, RCU is used heavily by +discussion <Performance and Scalability_>`__, RCU is used heavily by hot code paths in performance-critical portions of the Linux kernel's networking, security, virtualization, and scheduling code paths. RCU must therefore use efficient implementations, especially in its |