diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/cgroups/cpusets.txt | 2 | ||||
| -rw-r--r-- | Documentation/memory-hotplug.txt | 5 | ||||
| -rw-r--r-- | Documentation/vm/transhuge.txt | 19 |
3 files changed, 22 insertions, 4 deletions
diff --git a/Documentation/cgroups/cpusets.txt b/Documentation/cgroups/cpusets.txt index cefd3d8bbd1..12e01d432bf 100644 --- a/Documentation/cgroups/cpusets.txt +++ b/Documentation/cgroups/cpusets.txt @@ -218,7 +218,7 @@ and name space for cpusets, with a minimum of additional kernel code. The cpus and mems files in the root (top_cpuset) cpuset are read-only. The cpus file automatically tracks the value of cpu_online_mask using a CPU hotplug notifier, and the mems file -automatically tracks the value of node_states[N_HIGH_MEMORY]--i.e., +automatically tracks the value of node_states[N_MEMORY]--i.e., nodes with memory--using the cpuset_track_online_nodes() hook. diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt index c6f993d491b..8e5eacbdcfa 100644 --- a/Documentation/memory-hotplug.txt +++ b/Documentation/memory-hotplug.txt @@ -390,6 +390,7 @@ struct memory_notify { unsigned long start_pfn; unsigned long nr_pages; int status_change_nid_normal; + int status_change_nid_high; int status_change_nid; } @@ -397,7 +398,9 @@ start_pfn is start_pfn of online/offline memory. nr_pages is # of pages of online/offline memory. status_change_nid_normal is set node id when N_NORMAL_MEMORY of nodemask is (will be) set/clear, if this is -1, then nodemask status is not changed. -status_change_nid is set node id when N_HIGH_MEMORY of nodemask is (will be) +status_change_nid_high is set node id when N_HIGH_MEMORY of nodemask +is (will be) set/clear, if this is -1, then nodemask status is not changed. +status_change_nid is set node id when N_MEMORY of nodemask is (will be) set/clear. It means a new(memoryless) node gets new memory by online and a node loses all memory. If this is -1, then nodemask status is not changed. If status_changed_nid* >= 0, callback should create/discard structures for the diff --git a/Documentation/vm/transhuge.txt b/Documentation/vm/transhuge.txt index f734bb2a78d..8785fb87d9c 100644 --- a/Documentation/vm/transhuge.txt +++ b/Documentation/vm/transhuge.txt @@ -116,6 +116,13 @@ echo always >/sys/kernel/mm/transparent_hugepage/defrag echo madvise >/sys/kernel/mm/transparent_hugepage/defrag echo never >/sys/kernel/mm/transparent_hugepage/defrag +By default kernel tries to use huge zero page on read page fault. +It's possible to disable huge zero page by writing 0 or enable it +back by writing 1: + +echo 0 >/sys/kernel/mm/transparent_hugepage/khugepaged/use_zero_page +echo 1 >/sys/kernel/mm/transparent_hugepage/khugepaged/use_zero_page + khugepaged will be automatically started when transparent_hugepage/enabled is set to "always" or "madvise, and it'll be automatically shutdown if it's set to "never". @@ -197,6 +204,14 @@ thp_split is incremented every time a huge page is split into base pages. This can happen for a variety of reasons but a common reason is that a huge page is old and is being reclaimed. +thp_zero_page_alloc is incremented every time a huge zero page is + successfully allocated. It includes allocations which where + dropped due race with other allocation. Note, it doesn't count + every map of the huge zero page, only its allocation. + +thp_zero_page_alloc_failed is incremented if kernel fails to allocate + huge zero page and falls back to using small pages. + As the system ages, allocating huge pages may be expensive as the system uses memory compaction to copy data around memory to free a huge page for use. There are some counters in /proc/vmstat to help @@ -276,7 +291,7 @@ unaffected. libhugetlbfs will also work fine as usual. == Graceful fallback == Code walking pagetables but unware about huge pmds can simply call -split_huge_page_pmd(mm, pmd) where the pmd is the one returned by +split_huge_page_pmd(vma, addr, pmd) where the pmd is the one returned by pmd_offset. It's trivial to make the code transparent hugepage aware by just grepping for "pmd_offset" and adding split_huge_page_pmd where missing after pmd_offset returns the pmd. Thanks to the graceful @@ -299,7 +314,7 @@ diff --git a/mm/mremap.c b/mm/mremap.c return NULL; pmd = pmd_offset(pud, addr); -+ split_huge_page_pmd(mm, pmd); ++ split_huge_page_pmd(vma, addr, pmd); if (pmd_none_or_clear_bad(pmd)) return NULL; |