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 <ge...@linux-m68k.org>
---
v2:
- Improve readability:
- Divide by (SZ_1G / SZ_128K) instead of using a shift,
- Invert min/max order to keep calculating in pages until the last
step.
---
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 35bb51c31fff370f..8cfa01243ed27b6f 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);
--
2.17.1
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