在 2023/6/16 21:26, Mattijs Korpershoek 写道:
Commit 62649165cb02 ("lib: sparse: Make CHUNK_TYPE_RAW buffer aligned")
fixed cache alignment for systems with a D-CACHE.
However it introduced some performance regressions [1] on system
flashing huge images, such as Android.
On AM62x SK EVM, we also observe such performance penalty:
Sending sparse 'super' 1/2 (768793 KB) OKAY [ 23.954s]
Writing 'super' OKAY [ 75.926s]
Sending sparse 'super' 2/2 (629819 KB) OKAY [ 19.641s]
Writing 'super' OKAY [ 62.849s]
Finished. Total time: 182.474s
The reason for this is that we use an arbitrary small buffer
(info->blksz * 100) for transferring.
Fix it by using a bigger buffer (info->blksz * blkcnt) as suggested in
the original's patch review [2].
With this patch, performance impact is mitigated:
Sending sparse 'super' 1/2 (768793 KB) OKAY [ 24.006s]
Writing 'super' OKAY [ 15.920s]
Sending sparse 'super' 2/2 (629819 KB) OKAY [ 19.651s]
Writing 'super' OKAY [ 14.665s]
Finished. Total time: 74.346s
[1]
https://lore.kernel.org/r/[email protected]
[2] https://lore.kernel.org/r/all/[email protected]/
Fixes: 62649165cb02 ("lib: sparse: Make CHUNK_TYPE_RAW buffer aligned")
Signed-off-by: Mattijs Korpershoek <[email protected]>
---
lib/image-sparse.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/image-sparse.c b/lib/image-sparse.c
index 5ec0f94ab3eb..25aed0604192 100644
--- a/lib/image-sparse.c
+++ b/lib/image-sparse.c
@@ -55,7 +55,7 @@ static lbaint_t write_sparse_chunk_raw(struct sparse_storage
*info,
void *data,
char *response)
{
- lbaint_t n = blkcnt, write_blks, blks = 0, aligned_buf_blks = 100;
+ lbaint_t n = blkcnt, write_blks, blks = 0, aligned_buf_blks = blkcnt;
Hi:
It's a good point that this code report the performance was affected by
write large small
mmc blks, not memory copy.
And I can not make sure whether memalign can always alloc such huge
memory when we change the
aligned_buf_blks to blkcnt.
Could you please set aligned_buf_blks to FASTBOOT_MAX_BLK_WRITE(16384)
and test again?
uint32_t *aligned_buf = NULL;
if (CONFIG_IS_ENABLED(SYS_DCACHE_OFF)) {
---
base-commit: 2f4664f5c3edc55b18d8906f256a4c8e303243c0
change-id: 20230616-sparse-flash-fix-9c2852aa8d16
Best regards,
