linux-toradex.git/Documentation/vm/transhuge.txt, branch v4.4.72

Documentation/vm/transhuge.txt: add information about max_ptes_swap

2015-11-06T03:34:48+00:00

max_ptes_swap specifies how many pages can be brought in from swap when
collapsing a group of pages into a transparent huge page.

/sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_swap

A higher value can cause excessive swap IO and waste memory.  A lower
value can prevent THPs from being collapsed, resulting fewer pages being
collapsed into THPs, and lower memory access performance.

Signed-off-by: Ebru Akagunduz 
Acked-by: Rik van Riel 
Acked-by: David Rientjes 
Cc: Oleg Nesterov 
Cc: Kirill A. Shutemov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

doc: add information about max_ptes_none

2015-03-20T13:41:55+00:00

max_ptes_none specifies how many extra small pages (that are
not already mapped) can be allocated when collapsing a group
of small pages into one large page.

/sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_none

A higher value leads to use additional memory for programs.
A lower value leads to gain less thp performance. Value of
max_ptes_none can waste cpu time very little, you can
ignore it.

Signed-off-by: Ebru Akagunduz 
Reviewed-by: Rik van Riel 
Signed-off-by: Jonathan Corbet

doc: spelling error changes

2014-05-05T13:32:05+00:00

Fixed multiple spelling errors.

Acked-by: Randy Dunlap 
Signed-off-by: Carlos E. Garcia 
Signed-off-by: Jiri Kosina

mm/thp: fix doc for transparent huge zero page

2013-07-09T17:33:23+00:00

Transparent huge zero page is used during the page fault instead of in
khugepaged.

  # ls /sys/kernel/mm/transparent_hugepage/
  defrag  enabled  khugepaged  use_zero_page
  # ls /sys/kernel/mm/transparent_hugepage/khugepaged/
  alloc_sleep_millisecs  defrag  full_scans  max_ptes_none  pages_collapsed  pages_to_scan  scan_sleep_millisecs

This patch corrects the documentation just like the codes done.

Signed-off-by: Wanpeng Li 
Acked-by: Kirill A. Shutemov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: introduce sysfs knob to disable huge zero page

2012-12-13T01:38:32+00:00

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

Signed-off-by: Kirill A. Shutemov 
Cc: Andrea Arcangeli 
Cc: Andi Kleen 
Cc: "H. Peter Anvin" 
Cc: Mel Gorman 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp, vmstat: implement HZP_ALLOC and HZP_ALLOC_FAILED events

2012-12-13T01:38:32+00:00

hzp_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.

hzp_alloc_failed is incremented if kernel fails to allocate huge zero
	page and falls back to using small pages.

Signed-off-by: Kirill A. Shutemov 
Cc: Andrea Arcangeli 
Cc: Andi Kleen 
Cc: "H. Peter Anvin" 
Cc: Mel Gorman 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: change split_huge_page_pmd() interface

2012-12-13T01:38:31+00:00

Pass vma instead of mm and add address parameter.

In most cases we already have vma on the stack. We provides
split_huge_page_pmd_mm() for few cases when we have mm, but not vma.

This change is preparation to huge zero pmd splitting implementation.

Signed-off-by: Kirill A. Shutemov 
Cc: Andrea Arcangeli 
Cc: Andi Kleen 
Cc: "H. Peter Anvin" 
Cc: Mel Gorman 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: document the meminfo and vmstat fields of relevance to transparent hugepages

2012-05-29T23:22:23+00:00

Update Documentation/vm/transhuge.txt and
Documentation/filesystems/proc.txt with some information on monitoring
transparent huge page usage and the associated overhead.

Signed-off-by: Mel Gorman 
Signed-off-by: Andrea Arcangeli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: fix khugepaged defrag tunable documentation

2011-09-22T21:27:14+00:00

Commit e27e6151b154 ("mm/thp: use conventional format for boolean
attributes") changed

  /sys/kernel/mm/transparent_hugepage/khugepaged/defrag

to be tuned by using 1 (enabled) or 0 (disabled) instead of "yes" and
"no", respectively.

Update the documentation.

Signed-off-by: David Rientjes 
Signed-off-by: Linus Torvalds

thp: transparent hugepage support documentation

2011-01-14T01:32:38+00:00

Documentation/vm/transhuge.txt

Signed-off-by: Andrea Arcangeli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds