lkml.org 
[lkml]   [2020]   [Sep]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH v2] cma_alloc(), indefinitely retry allocations for -EBUSY failures
Date
[PATCH v2] cma_alloc(), indefinitely retry allocations for -EBUSY failures

On mobile devices, failure to allocate from a CMA area constitutes a
functional failure. Sometimes during CMA allocations, we have observed
that pages in a CMA area allocated through alloc_pages(), that we're trying
to migrate away to make room for a CMA allocation, are temporarily pinned.
This temporary pinning can occur when a process that owns the pinned page
is being forked (the example is explained further in the commit text), or it is
exiting. This patch addresses this issue by indefinitely retrying allocations
that fail due to a return of -EBUSY.

** This change log was re-sent due to threading issues **

Change log:

v1: We were performing retries of the allocation a fixed number of times.
Andrew Morton disliked this, as it didn't guarantee that the allocation would
succeed.

https://lkml.org/lkml/2020/8/5/1096
https://lkml.org/lkml/2020/8/21/1490

v2: To address this concern, we switched to retrying indefinitely, as opposed to
doing to retrying the allocation a limited number of times.

Chris Goldsworthy (1):
mm: cma: indefinitely retry allocations in cma_alloc

mm/cma.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)

--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

\
 
 \ /
  Last update: 2020-09-11 22:54    [W:0.080 / U:0.864 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site