diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/DocBook/debugobjects.tmpl | 26 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 8 | ||||
| -rw-r--r-- | Documentation/memory-hotplug.txt | 9 | ||||
| -rw-r--r-- | Documentation/sysctl/vm.txt | 14 | ||||
| -rw-r--r-- | Documentation/vm/transhuge.txt | 10 |
5 files changed, 46 insertions, 21 deletions
diff --git a/Documentation/DocBook/debugobjects.tmpl b/Documentation/DocBook/debugobjects.tmpl index 24979f691e3e..7e4f34fde697 100644 --- a/Documentation/DocBook/debugobjects.tmpl +++ b/Documentation/DocBook/debugobjects.tmpl @@ -316,8 +316,8 @@ </itemizedlist> </para> <para> - The function returns 1 when the fixup was successful, - otherwise 0. The return value is used to update the + The function returns true when the fixup was successful, + otherwise false. The return value is used to update the statistics. </para> <para> @@ -341,8 +341,8 @@ </itemizedlist> </para> <para> - The function returns 1 when the fixup was successful, - otherwise 0. The return value is used to update the + The function returns true when the fixup was successful, + otherwise false. The return value is used to update the statistics. </para> <para> @@ -359,7 +359,8 @@ statically initialized object or not. In case it is it calls debug_object_init() and debug_object_activate() to make the object known to the tracker and marked active. In this case - the function should return 0 because this is not a real fixup. + the function should return false because this is not a real + fixup. </para> </sect1> @@ -376,8 +377,8 @@ </itemizedlist> </para> <para> - The function returns 1 when the fixup was successful, - otherwise 0. The return value is used to update the + The function returns true when the fixup was successful, + otherwise false. The return value is used to update the statistics. </para> </sect1> @@ -397,8 +398,8 @@ </itemizedlist> </para> <para> - The function returns 1 when the fixup was successful, - otherwise 0. The return value is used to update the + The function returns true when the fixup was successful, + otherwise false. The return value is used to update the statistics. </para> </sect1> @@ -414,8 +415,8 @@ debug bucket. </para> <para> - The function returns 1 when the fixup was successful, - otherwise 0. The return value is used to update the + The function returns true when the fixup was successful, + otherwise false. The return value is used to update the statistics. </para> <para> @@ -427,7 +428,8 @@ case. The fixup function should check if this is a legitimate case of a statically initialized object or not. In this case only debug_object_init() should be called to make the object known to - the tracker. Then the function should return 0 because this is not + the tracker. Then the function should return false because this + is not a real fixup. </para> </sect1> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index f5c35901144c..18d7f5bea077 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2168,6 +2168,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted. [KNL,SH] Allow user to override the default size for per-device physically contiguous DMA buffers. + memhp_default_state=online/offline + [KNL] Set the initial state for the memory hotplug + onlining policy. If not specified, the default value is + set according to the + CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE kernel config + option. + See Documentation/memory-hotplug.txt. + memmap=exactmap [KNL,X86] Enable setting of an exact E820 memory map, as specified by the user. Such memmap=exactmap lines can be constructed based on diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt index 443f4b44ad97..0d7cb955aa01 100644 --- a/Documentation/memory-hotplug.txt +++ b/Documentation/memory-hotplug.txt @@ -261,10 +261,11 @@ it according to the policy which can be read from "auto_online_blocks" file: % cat /sys/devices/system/memory/auto_online_blocks -The default is "offline" which means the newly added memory is not in a -ready-to-use state and you have to "online" the newly added memory blocks -manually. Automatic onlining can be requested by writing "online" to -"auto_online_blocks" file: +The default depends on the CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE kernel config +option. If it is disabled the default is "offline" which means the newly added +memory is not in a ready-to-use state and you have to "online" the newly added +memory blocks manually. Automatic onlining can be requested by writing "online" +to "auto_online_blocks" file: % echo online > /sys/devices/system/memory/auto_online_blocks diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 34a5fece3121..720355cbdf45 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -57,6 +57,7 @@ Currently, these files are in /proc/sys/vm: - panic_on_oom - percpu_pagelist_fraction - stat_interval +- stat_refresh - swappiness - user_reserve_kbytes - vfs_cache_pressure @@ -755,6 +756,19 @@ is 1 second. ============================================================== +stat_refresh + +Any read or write (by root only) flushes all the per-cpu vm statistics +into their global totals, for more accurate reports when testing +e.g. cat /proc/sys/vm/stat_refresh /proc/meminfo + +As a side-effect, it also checks for negative totals (elsewhere reported +as 0) and "fails" with EINVAL if any are found, with a warning in dmesg. +(At time of writing, a few stats are known sometimes to be found negative, +with no ill effects: errors and warnings on these stats are suppressed.) + +============================================================== + swappiness This control is used to define how aggressive the kernel will swap diff --git a/Documentation/vm/transhuge.txt b/Documentation/vm/transhuge.txt index d9cb65cf5cfd..fb0e1f2a19cc 100644 --- a/Documentation/vm/transhuge.txt +++ b/Documentation/vm/transhuge.txt @@ -394,9 +394,9 @@ hugepage natively. Once finished you can drop the page table lock. Refcounting on THP is mostly consistent with refcounting on other compound pages: - - get_page()/put_page() and GUP operate in head page's ->_count. + - get_page()/put_page() and GUP operate in head page's ->_refcount. - - ->_count in tail pages is always zero: get_page_unless_zero() never + - ->_refcount in tail pages is always zero: get_page_unless_zero() never succeed on tail pages. - map/unmap of the pages with PTE entry increment/decrement ->_mapcount @@ -426,15 +426,15 @@ requests to split pinned huge page: it expects page count to be equal to sum of mapcount of all sub-pages plus one (split_huge_page caller must have reference for head page). -split_huge_page uses migration entries to stabilize page->_count and +split_huge_page uses migration entries to stabilize page->_refcount and page->_mapcount. We safe against physical memory scanners too: the only legitimate way scanner can get reference to a page is get_page_unless_zero(). -All tail pages has zero ->_count until atomic_add(). It prevent scanner +All tail pages has zero ->_refcount until atomic_add(). It prevent scanner from geting reference to tail page up to the point. After the atomic_add() -we don't care about ->_count value. We already known how many references +we don't care about ->_refcount value. We already known how many references with should uncharge from head page. For head page get_page_unless_zero() will succeed and we don't mind. It's |