[PATCH 2/2] dmaengine: ioat: Decreasing allocation chunk size 2M -> 512K

From: leonid . ravich
Date: Thu Apr 02 2020 - 05:38:47 EST


From: Leonid Ravich <Leonid.Ravich@xxxxxxx>

current IOAT driver using big (2MB) allocations chunk for its descriptors
therefore each ioat dma engine need 2 such chunks
(64k entres in ring each entry 64B = 4MB)
requiring 2 * 2M * dmaengine contiguies memory chunk
might fail due to memory fragmention.

so we decresging chunk size and using more chunks.

Signed-off-by: Leonid Ravich <Leonid.Ravich@xxxxxxx>
---
drivers/dma/ioat/dma.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
index 535aba9..e9757bc 100644
--- a/drivers/dma/ioat/dma.h
+++ b/drivers/dma/ioat/dma.h
@@ -83,7 +83,7 @@ struct ioatdma_device {

#define IOAT_MAX_ORDER 16
#define IOAT_MAX_DESCS (1 << IOAT_MAX_ORDER)
-#define IOAT_CHUNK_SIZE (SZ_2M)
+#define IOAT_CHUNK_SIZE (SZ_512K)
#define IOAT_DESCS_PER_CHUNK (IOAT_CHUNK_SIZE/IOAT_DESC_SZ)

struct ioat_descs {
--
1.9.3