Am 04.06.24 um 12:18 schrieb Huang Rui:
On Tue, Jun 04, 2024 at 04:49:34PM +0800, Zhu, Lingshan wrote:
ttm page fault handler ttm_bo_vm_fault_reserved() maps
TTM_BO_VM_NUM_PREFAULT more pages beforehand
due to the principle of locality.
However, on some platform the page faults are more costly, this
patch intends to increase the number of ttm pre-fault to relieve
the number of page faults.
When multiple levels of page table is supported, the new default
value would be the PMD size, similar to huge page.
Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxx>
Reported-and-tested-by: Li Jingxiang <jingxiang.li@xxxxxxxxxxxxxx>
Acked-by: Huang Rui <ray.huang@xxxxxxx>
Not sure if there really is an architecture with less than 3 page table
levels, but the build robots should be able to tell us if everything is
fine here.
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
---
include/drm/ttm/ttm_bo.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h
index 6ccf96c91f3a..ef0f52f56ebc 100644
--- a/include/drm/ttm/ttm_bo.h
+++ b/include/drm/ttm/ttm_bo.h
@@ -39,7 +39,11 @@
#include "ttm_device.h"
/* Default number of pre-faulted pages in the TTM fault handler */
+#if CONFIG_PGTABLE_LEVELS > 2
+#define TTM_BO_VM_NUM_PREFAULT (1 << (PMD_SHIFT - PAGE_SHIFT))
+#else
#define TTM_BO_VM_NUM_PREFAULT 16
+#endif
struct iosys_map;
--
2.45.1
