diff options
| author |   José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-11 10:41:07 +0300 |
|---|---|---|
| committer | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-13 08:17:18 +0300 |
| commit | e09b41010ba33a20a87472ee821fa407a5b8da36 (patch) | |
| tree | d10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/Documentation/vm/page_migration | |
| parent | f93b97fd65072de626c074dbe099a1fff05ce060 (diff) | |
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page.
During the rebasing, the following patch collided:
Force tick interrupt and get rid of softirq magic(I70131fb85).
Collisions have been removed because its logic was found on the
source already.
Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/Documentation/vm/page_migration')
| -rw-r--r-- | kernel/Documentation/vm/page_migration | 27 |
1 files changed, 12 insertions, 15 deletions
diff --git a/kernel/Documentation/vm/page_migration b/kernel/Documentation/vm/page_migration index 6513fe2d9..fea5c0864 100644 --- a/kernel/Documentation/vm/page_migration +++ b/kernel/Documentation/vm/page_migration @@ -92,29 +92,26 @@ Steps: 2. Insure that writeback is complete. -3. Prep the new page that we want to move to. It is locked - and set to not being uptodate so that all accesses to the new - page immediately lock while the move is in progress. +3. Lock the new page that we want to move to. It is locked so that accesses to + this (not yet uptodate) page immediately lock while the move is in progress. -4. The new page is prepped with some settings from the old page so that - accesses to the new page will discover a page with the correct settings. - -5. All the page table references to the page are converted - to migration entries or dropped (nonlinear vmas). - This decrease the mapcount of a page. If the resulting - mapcount is not zero then we do not migrate the page. - All user space processes that attempt to access the page - will now wait on the page lock. +4. All the page table references to the page are converted to migration + entries. This decreases the mapcount of a page. If the resulting + mapcount is not zero then we do not migrate the page. All user space + processes that attempt to access the page will now wait on the page lock. -6. The radix tree lock is taken. This will cause all processes trying +5. The radix tree lock is taken. This will cause all processes trying to access the page via the mapping to block on the radix tree spinlock. -7. The refcount of the page is examined and we back out if references remain +6. The refcount of the page is examined and we back out if references remain otherwise we know that we are the only one referencing this page. -8. The radix tree is checked and if it does not contain the pointer to this +7. The radix tree is checked and if it does not contain the pointer to this page then we back out because someone else modified the radix tree. +8. The new page is prepped with some settings from the old page so that + accesses to the new page will discover a page with the correct settings. + 9. The radix tree is changed to point to the new page. 10. The reference count of the old page is dropped because the radix tree |