diff options
Diffstat (limited to 'Documentation/core-api')
| -rw-r--r-- | Documentation/core-api/cpu_hotplug.rst | 13 | ||||
| -rw-r--r-- | Documentation/core-api/kernel-api.rst | 18 | ||||
| -rw-r--r-- | Documentation/core-api/pin_user_pages.rst | 6 |
3 files changed, 26 insertions, 11 deletions
diff --git a/Documentation/core-api/cpu_hotplug.rst b/Documentation/core-api/cpu_hotplug.rst index f75778d37488..e6f5bc39cf5c 100644 --- a/Documentation/core-api/cpu_hotplug.rst +++ b/Documentation/core-api/cpu_hotplug.rst @@ -127,17 +127,8 @@ bring CPU4 back online:: $ echo 1 > /sys/devices/system/cpu/cpu4/online smpboot: Booting Node 0 Processor 4 APIC 0x1 -The CPU is usable again. This should work on all CPUs. CPU0 is often special -and excluded from CPU hotplug. On X86 the kernel option -*CONFIG_BOOTPARAM_HOTPLUG_CPU0* has to be enabled in order to be able to -shutdown CPU0. Alternatively the kernel command option *cpu0_hotplug* can be -used. Some known dependencies of CPU0: - -* Resume from hibernate/suspend. Hibernate/suspend will fail if CPU0 is offline. -* PIC interrupts. CPU0 can't be removed if a PIC interrupt is detected. - -Please let Fenghua Yu <fenghua.yu@intel.com> know if you find any dependencies -on CPU0. +The CPU is usable again. This should work on all CPUs, but CPU0 is often special +and excluded from CPU hotplug. The CPU hotplug coordination ============================ diff --git a/Documentation/core-api/kernel-api.rst b/Documentation/core-api/kernel-api.rst index 9b3f3e5f5a95..f2bcc5a7ea43 100644 --- a/Documentation/core-api/kernel-api.rst +++ b/Documentation/core-api/kernel-api.rst @@ -96,6 +96,12 @@ Command-line Parsing .. kernel-doc:: lib/cmdline.c :export: +Error Pointers +-------------- + +.. kernel-doc:: include/linux/err.h + :internal: + Sorting ------- @@ -412,3 +418,15 @@ Read-Copy Update (RCU) .. kernel-doc:: include/linux/rcu_sync.h .. kernel-doc:: kernel/rcu/sync.c + +.. kernel-doc:: kernel/rcu/tasks.h + +.. kernel-doc:: kernel/rcu/tree_stall.h + +.. kernel-doc:: include/linux/rcupdate_trace.h + +.. kernel-doc:: include/linux/rcupdate_wait.h + +.. kernel-doc:: include/linux/rcuref.h + +.. kernel-doc:: include/linux/rcutree.h diff --git a/Documentation/core-api/pin_user_pages.rst b/Documentation/core-api/pin_user_pages.rst index 9fb0b1080d3b..d3c1f6d8c0e0 100644 --- a/Documentation/core-api/pin_user_pages.rst +++ b/Documentation/core-api/pin_user_pages.rst @@ -112,6 +112,12 @@ pages: This also leads to limitations: there are only 31-10==21 bits available for a counter that increments 10 bits at a time. +* Because of that limitation, special handling is applied to the zero pages + when using FOLL_PIN. We only pretend to pin a zero page - we don't alter its + refcount or pincount at all (it is permanent, so there's no need). The + unpinning functions also don't do anything to a zero page. This is + transparent to the caller. + * Callers must specifically request "dma-pinned tracking of pages". In other words, just calling get_user_pages() will not suffice; a new set of functions, pin_user_page() and related, must be used. |