Re: [PATCH] swiotlb: suppress warning when __GFP_NOWARN is set.

From: Konrad Rzeszutek Wilk
Date: Tue Dec 19 2017 - 09:52:40 EST


On December 19, 2017 9:32:55 AM EST, "Christian KÃnig" <ckoenig.leichtzumerken@xxxxxxxxx> wrote:
>TTM tries to allocate coherent memory in chunks of 2MB first to improve
>TLB efficiency and falls back to allocating 4K pages if that fails.
>
>Suppress the warning when the 2MB allocations fails since there is a
>valid fall back path.
>
>Signed-off-by: Christian KÃnig <christian.koenig@xxxxxxx>

Is there an Reported by or such needed?

>---
> lib/swiotlb.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
>diff --git a/lib/swiotlb.c b/lib/swiotlb.c
>index cea19aaf303c..63a44fb29ce6 100644
>--- a/lib/swiotlb.c
>+++ b/lib/swiotlb.c
>@@ -769,9 +769,11 @@ swiotlb_alloc_coherent(struct device *hwdev,
>size_t size,
> return ret;
>
> err_warn:
>- pr_warn("swiotlb: coherent allocation failed for device %s
>size=%zu\n",
>- dev_name(hwdev), size);
>- dump_stack();
>+ if (!(flags & __GFP_NOWARN)) {
>+ pr_warn("swiotlb: coherent allocation failed for device %s
>size=%zu\n",
>+ dev_name(hwdev), size);
>+ dump_stack();
>+ }

Ok, let me queue it up.
>
> return NULL;
> }