From: Geert Uytterhoeven geert@linux-m68k.org
upstream 3ee06a6d532f75f20528ff4d2c473cda36c484fe commit.
On systems with at least 32 MiB, but less than 32 GiB of RAM, the DMA memory pools are much larger than intended (e.g. 2 MiB instead of 128 KiB on a 256 MiB system).
Fix this by correcting the calculation of the number of GiBs of RAM in the system. Invert the order of the min/max operations, to keep on calculating in pages until the last step, which aids readability.
Fixes: 1d659236fb43c4d2 ("dma-pool: scale the default DMA coherent pool size with memory capacity") Signed-off-by: Geert Uytterhoeven geert@linux-m68k.org Acked-by: David Rientjes rientjes@google.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Peter Gonda pgonda@google.com --- kernel/dma/pool.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c index 35bb51c31fff..8cfa01243ed2 100644 --- a/kernel/dma/pool.c +++ b/kernel/dma/pool.c @@ -175,10 +175,9 @@ static int __init dma_atomic_pool_init(void) * sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER-1. */ if (!atomic_pool_size) { - atomic_pool_size = max(totalram_pages() >> PAGE_SHIFT, 1UL) * - SZ_128K; - atomic_pool_size = min_t(size_t, atomic_pool_size, - 1 << (PAGE_SHIFT + MAX_ORDER-1)); + unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K); + pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES); + atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K); } INIT_WORK(&atomic_pool_work, atomic_pool_work_fn);