A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-30 03:27:44 -04:00
Code Issues Projects Releases Packages Wiki Activity

mm: reference totalram_pages and managed_pages once per function

Browse source 
Patch series "mm: convert totalram_pages, totalhigh_pages and managed
pages to atomic", v5.

This series converts totalram_pages, totalhigh_pages and
zone->managed_pages to atomic variables.

totalram_pages, zone->managed_pages and totalhigh_pages updates are
protected by managed_page_count_lock, but readers never care about it.
Convert these variables to atomic to avoid readers potentially seeing a
store tear.

Main motivation was that managed_page_count_lock handling was complicating
things.  It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 It seemes better
to remove the lock and convert variables to atomic.  With the change,
preventing poteintial store-to-read tearing comes as a bonus.

This patch (of 4):

This is in preparation to a later patch which converts totalram_pages and
zone->managed_pages to atomic variables.  Please note that re-reading the
value might lead to a different value and as such it could lead to
unexpected behavior.  There are no known bugs as a result of the current
code but it is better to prevent from them in principle.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arun KS <[email protected]>
Reviewed-by: Konstantin Khlebnikov <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Reviewed-by: Pavel Tatashin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Arun KS 2018-12-28 00:34:20 -08:00 • committed by Linus Torvalds
commit 3d6357de8a
12 changed files with 44 additions and 33 deletions
Download patch file Download diff file Expand all files Collapse all files

7
net/dccp/proto.c
View file

@ -1131,6 +1131,7 @@ EXPORT_SYMBOL_GPL(dccp_debug);
static int __init dccp_init(void)
{
unsigned long goal;
unsigned long nr_pages = totalram_pages;
int ehash_order, bhash_order, i;
int rc;
@ -1157,10 +1158,10 @@ static int __init dccp_init(void)
*
* The methodology is similar to that of the buffer cache.
*/
if (totalram_pages >= (128 * 1024))
goal = totalram_pages >> (21 - PAGE_SHIFT);
if (nr_pages >= (128 * 1024))
goal = nr_pages >> (21 - PAGE_SHIFT);
else
goal = totalram_pages >> (23 - PAGE_SHIFT);
goal = nr_pages >> (23 - PAGE_SHIFT);
if (thash_entries)
goal = (thash_entries *