[lkml]   [2020]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[rfc 6/6] dma-remap: double the default DMA coherent pool size
When AMD memory encryption is enabled, some devices may used more than
256KB/sec from the atomic pools. Double the default size to make the
original size and expansion more appropriate.

This provides a slight optimization on initial expansion and is deemed
appropriate for all configs with CONFIG_DMA_REMAP enabled because of the
increased reliance on the atomic pools.

Alternatively, this could be done only when CONFIG_AMD_MEM_ENCRYPT is

Signed-off-by: David Rientjes <>
kernel/dma/remap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -105,7 +105,7 @@ static struct gen_pool *atomic_pool __ro_after_init;
static struct gen_pool *atomic_pool_dma32 __ro_after_init;
static struct gen_pool *atomic_pool_normal __ro_after_init;

static size_t atomic_pool_size = DEFAULT_DMA_COHERENT_POOL_SIZE;

/* Dynamic background expansion when the atomic pool is near capacity */
 \ /
  Last update: 2020-03-02 01:05    [W:0.228 / U:0.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site