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/balance | |
| 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/balance')
| -rw-r--r-- | kernel/Documentation/vm/balance | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/kernel/Documentation/vm/balance b/kernel/Documentation/vm/balance index c46e68cf9..964595481 100644 --- a/kernel/Documentation/vm/balance +++ b/kernel/Documentation/vm/balance @@ -1,12 +1,14 @@ Started Jan 2000 by Kanoj Sarcar <kanoj@sgi.com> -Memory balancing is needed for non __GFP_WAIT as well as for non -__GFP_IO allocations. +Memory balancing is needed for !__GFP_ATOMIC and !__GFP_KSWAPD_RECLAIM as +well as for non __GFP_IO allocations. -There are two reasons to be requesting non __GFP_WAIT allocations: -the caller can not sleep (typically intr context), or does not want -to incur cost overheads of page stealing and possible swap io for -whatever reasons. +The first reason why a caller may avoid reclaim is that the caller can not +sleep due to holding a spinlock or is in interrupt context. The second may +be that the caller is willing to fail the allocation without incurring the +overhead of page reclaim. This may happen for opportunistic high-order +allocation requests that have order-0 fallback options. In such cases, +the caller may also wish to avoid waking kswapd. __GFP_IO allocation requests are made to prevent file system deadlocks. |