Loading Documentation/ABI/testing/sysfs-bus-usb +1 −1 Original line number Diff line number Diff line Loading @@ -160,7 +160,7 @@ Description: match the driver to the device. For example: # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id What: /sys/bus/usb/device/.../avoid_reset What: /sys/bus/usb/device/.../avoid_reset_quirk Date: December 2009 Contact: Oliver Neukum <oliver@neukum.org> Description: Loading Documentation/PCI/PCI-DMA-mapping.txt→Documentation/DMA-API-HOWTO.txt +0 −0 File moved. View file Documentation/DocBook/tracepoint.tmpl +13 −0 Original line number Diff line number Diff line Loading @@ -16,6 +16,15 @@ </address> </affiliation> </author> <author> <firstname>William</firstname> <surname>Cohen</surname> <affiliation> <address> <email>wcohen@redhat.com</email> </address> </affiliation> </author> </authorgroup> <legalnotice> Loading Loading @@ -91,4 +100,8 @@ !Iinclude/trace/events/signal.h </chapter> <chapter id="block"> <title>Block IO</title> !Iinclude/trace/events/block.h </chapter> </book> Documentation/RCU/NMI-RCU.txt +22 −17 Original line number Diff line number Diff line Loading @@ -34,7 +34,7 @@ NMI handler. cpu = smp_processor_id(); ++nmi_count(cpu); if (!rcu_dereference(nmi_callback)(regs, cpu)) if (!rcu_dereference_sched(nmi_callback)(regs, cpu)) default_do_nmi(regs); nmi_exit(); Loading @@ -47,12 +47,13 @@ function pointer. If this handler returns zero, do_nmi() invokes the default_do_nmi() function to handle a machine-specific NMI. Finally, preemption is restored. Strictly speaking, rcu_dereference() is not needed, since this code runs only on i386, which does not need rcu_dereference() anyway. However, it is a good documentation aid, particularly for anyone attempting to do something similar on Alpha. In theory, rcu_dereference_sched() is not needed, since this code runs only on i386, which in theory does not need rcu_dereference_sched() anyway. However, in practice it is a good documentation aid, particularly for anyone attempting to do something similar on Alpha or on systems with aggressive optimizing compilers. Quick Quiz: Why might the rcu_dereference() be necessary on Alpha, Quick Quiz: Why might the rcu_dereference_sched() be necessary on Alpha, given that the code referenced by the pointer is read-only? Loading Loading @@ -99,17 +100,21 @@ invoke irq_enter() and irq_exit() on NMI entry and exit, respectively. Answer to Quick Quiz Why might the rcu_dereference() be necessary on Alpha, given Why might the rcu_dereference_sched() be necessary on Alpha, given that the code referenced by the pointer is read-only? Answer: The caller to set_nmi_callback() might well have initialized some data that is to be used by the new NMI handler. In this case, the rcu_dereference() would be needed, because otherwise a CPU that received an NMI just after the new handler was set might see the pointer to the new NMI handler, but the old pre-initialized version of the handler's data. More important, the rcu_dereference() makes it clear to someone reading the code that the pointer is being protected by RCU. initialized some data that is to be used by the new NMI handler. In this case, the rcu_dereference_sched() would be needed, because otherwise a CPU that received an NMI just after the new handler was set might see the pointer to the new NMI handler, but the old pre-initialized version of the handler's data. This same sad story can happen on other CPUs when using a compiler with aggressive pointer-value speculation optimizations. More important, the rcu_dereference_sched() makes it clear to someone reading the code that the pointer is being protected by RCU-sched. Documentation/RCU/checklist.txt +4 −3 Original line number Diff line number Diff line Loading @@ -260,7 +260,8 @@ over a rather long period of time, but improvements are always welcome! The reason that it is permissible to use RCU list-traversal primitives when the update-side lock is held is that doing so can be quite helpful in reducing code bloat when common code is shared between readers and updaters. shared between readers and updaters. Additional primitives are provided for this case, as discussed in lockdep.txt. 10. Conversely, if you are in an RCU read-side critical section, and you don't hold the appropriate update-side lock, you -must- Loading Loading @@ -344,8 +345,8 @@ over a rather long period of time, but improvements are always welcome! requiring SRCU's read-side deadlock immunity or low read-side realtime latency. Note that, rcu_assign_pointer() and rcu_dereference() relate to SRCU just as they do to other forms of RCU. Note that, rcu_assign_pointer() relates to SRCU just as they do to other forms of RCU. 15. The whole point of call_rcu(), synchronize_rcu(), and friends is to wait until all pre-existing readers have finished before Loading Loading
Documentation/ABI/testing/sysfs-bus-usb +1 −1 Original line number Diff line number Diff line Loading @@ -160,7 +160,7 @@ Description: match the driver to the device. For example: # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id What: /sys/bus/usb/device/.../avoid_reset What: /sys/bus/usb/device/.../avoid_reset_quirk Date: December 2009 Contact: Oliver Neukum <oliver@neukum.org> Description: Loading
Documentation/DocBook/tracepoint.tmpl +13 −0 Original line number Diff line number Diff line Loading @@ -16,6 +16,15 @@ </address> </affiliation> </author> <author> <firstname>William</firstname> <surname>Cohen</surname> <affiliation> <address> <email>wcohen@redhat.com</email> </address> </affiliation> </author> </authorgroup> <legalnotice> Loading Loading @@ -91,4 +100,8 @@ !Iinclude/trace/events/signal.h </chapter> <chapter id="block"> <title>Block IO</title> !Iinclude/trace/events/block.h </chapter> </book>
Documentation/RCU/NMI-RCU.txt +22 −17 Original line number Diff line number Diff line Loading @@ -34,7 +34,7 @@ NMI handler. cpu = smp_processor_id(); ++nmi_count(cpu); if (!rcu_dereference(nmi_callback)(regs, cpu)) if (!rcu_dereference_sched(nmi_callback)(regs, cpu)) default_do_nmi(regs); nmi_exit(); Loading @@ -47,12 +47,13 @@ function pointer. If this handler returns zero, do_nmi() invokes the default_do_nmi() function to handle a machine-specific NMI. Finally, preemption is restored. Strictly speaking, rcu_dereference() is not needed, since this code runs only on i386, which does not need rcu_dereference() anyway. However, it is a good documentation aid, particularly for anyone attempting to do something similar on Alpha. In theory, rcu_dereference_sched() is not needed, since this code runs only on i386, which in theory does not need rcu_dereference_sched() anyway. However, in practice it is a good documentation aid, particularly for anyone attempting to do something similar on Alpha or on systems with aggressive optimizing compilers. Quick Quiz: Why might the rcu_dereference() be necessary on Alpha, Quick Quiz: Why might the rcu_dereference_sched() be necessary on Alpha, given that the code referenced by the pointer is read-only? Loading Loading @@ -99,17 +100,21 @@ invoke irq_enter() and irq_exit() on NMI entry and exit, respectively. Answer to Quick Quiz Why might the rcu_dereference() be necessary on Alpha, given Why might the rcu_dereference_sched() be necessary on Alpha, given that the code referenced by the pointer is read-only? Answer: The caller to set_nmi_callback() might well have initialized some data that is to be used by the new NMI handler. In this case, the rcu_dereference() would be needed, because otherwise a CPU that received an NMI just after the new handler was set might see the pointer to the new NMI handler, but the old pre-initialized version of the handler's data. More important, the rcu_dereference() makes it clear to someone reading the code that the pointer is being protected by RCU. initialized some data that is to be used by the new NMI handler. In this case, the rcu_dereference_sched() would be needed, because otherwise a CPU that received an NMI just after the new handler was set might see the pointer to the new NMI handler, but the old pre-initialized version of the handler's data. This same sad story can happen on other CPUs when using a compiler with aggressive pointer-value speculation optimizations. More important, the rcu_dereference_sched() makes it clear to someone reading the code that the pointer is being protected by RCU-sched.
Documentation/RCU/checklist.txt +4 −3 Original line number Diff line number Diff line Loading @@ -260,7 +260,8 @@ over a rather long period of time, but improvements are always welcome! The reason that it is permissible to use RCU list-traversal primitives when the update-side lock is held is that doing so can be quite helpful in reducing code bloat when common code is shared between readers and updaters. shared between readers and updaters. Additional primitives are provided for this case, as discussed in lockdep.txt. 10. Conversely, if you are in an RCU read-side critical section, and you don't hold the appropriate update-side lock, you -must- Loading Loading @@ -344,8 +345,8 @@ over a rather long period of time, but improvements are always welcome! requiring SRCU's read-side deadlock immunity or low read-side realtime latency. Note that, rcu_assign_pointer() and rcu_dereference() relate to SRCU just as they do to other forms of RCU. Note that, rcu_assign_pointer() relates to SRCU just as they do to other forms of RCU. 15. The whole point of call_rcu(), synchronize_rcu(), and friends is to wait until all pre-existing readers have finished before Loading
