[lkml]   [2017]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 2/2] percpu: fix iteration to prevent skipping over block
On Wed, Sep 27, 2017 at 04:35:00PM -0500, Dennis Zhou wrote:
> The iterator functions pcpu_next_md_free_region and
> pcpu_next_fit_region use the block offset to determine if they have
> checked the area in the prior iteration. However, this causes an issue
> when the block offset is greater than subsequent block contig hints. If
> within the iterator it moves to check subsequent blocks, it may fail in
> the second predicate due to the block offset not being cleared. Thus,
> this causes the allocator to skip over blocks leading to false failures
> when allocating from the reserved chunk. While this happens in the
> general case as well, it will only fail if it cannot allocate a new
> chunk.
> This patch resets the block offset to 0 to pass the second predicate
> when checking subseqent blocks within the iterator function.
> Signed-off-by: Dennis Zhou <>
> Reported-by: Luis Henriques <>

Applied to percpu/for-4.14-fixes.



 \ /
  Last update: 2017-09-28 16:41    [W:0.068 / U:2.920 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site