Hi Qianfan,

Thank you for your review.

On ven., juil. 07, 2023 at 18:54, qianfan qianfanguijin@163.com wrote:

在 2023/7/7 16:13, 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 * FASTBOOT_MAX_BLK_WRITE) as suggested in the original's patch review [2].

With this patch, performance impact is mitigated: Sending sparse 'super' 1/2 (768793 KB) OKAY [ 23.912s] Writing 'super' OKAY [ 15.780s] Sending sparse 'super' 2/2 (629819 KB) OKAY [ 19.581s] Writing 'super' OKAY [ 17.192s] Finished. Total time: 76.569s

[1] https://lore.kernel.org/r/20221118121323.4009193-1-gary.bisson@boundarydevic... [2] https://lore.kernel.org/r/all/43e4c17c-4483-ec8e-f843-9b4c5569bd18@seco.com/

Fixes: 62649165cb02 ("lib: sparse: Make CHUNK_TYPE_RAW buffer aligned") Signed-off-by: Mattijs Korpershoek mkorpershoek@baylibre.com

---

Changes in v2:

• Use FASTBOOT_MAX_BLK_WRITE instead of blkcnt (Qianfan)
• Link to v1: https://lore.kernel.org/r/20230616-sparse-flash-fix-v1-1-6bafeacc567b@baylib...

---

drivers/fastboot/fb_mmc.c | 2 -- include/image-sparse.h | 2 ++ lib/image-sparse.c | 3 ++- 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/fastboot/fb_mmc.c b/drivers/fastboot/fb_mmc.c index 9d25c402028a..060918e49109 100644 --- a/drivers/fastboot/fb_mmc.c +++ b/drivers/fastboot/fb_mmc.c @@ -19,8 +19,6 @@ #include <linux/compat.h> #include <android_image.h>

-#define FASTBOOT_MAX_BLK_WRITE 16384

• #define BOOT_PARTITION_NAME "boot"

  struct fb_mmc_sparse {

diff --git a/include/image-sparse.h b/include/image-sparse.h index 0572dbd0a283..282a0b256498 100644 --- a/include/image-sparse.h +++ b/include/image-sparse.h @@ -7,6 +7,8 @@ #include <part.h> #include <sparse_format.h>

+#define FASTBOOT_MAX_BLK_WRITE 16384

Hi:

Just a personal suggestion, define sometings like FASTBOOT_MAX_BLK_WRITE in image-sparse.c is very strange.

Or maybe define a marco such as SPARSE_MAX_BLK_WRITE and set a default value to 16384, and leave some comments for why we choice this value.

I don't agree with having a duplicating between SPARSE_MAX_BLK_WRITE and FASTBOOT_MAX_BLK_WRITE. code comments can rot as well.

And FASTBOOT_MAX_BLK_WRITE is used for both sparse and unsparsed image, which is why I chose to not rename it.

Thanks.

...

• #define ROUNDUP(x, y) (((x) + ((y) - 1)) & ~((y) - 1))

  struct sparse_storage {

diff --git a/lib/image-sparse.c b/lib/image-sparse.c index 5ec0f94ab3eb..8f8a67e15804 100644 --- a/lib/image-sparse.c +++ b/lib/image-sparse.c @@ -55,7 +55,8 @@ 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;

• lbaint_t aligned_buf_blks = FASTBOOT_MAX_BLK_WRITE; uint32_t *aligned_buf = NULL;

  if (CONFIG_IS_ENABLED(SYS_DCACHE_OFF)) {

---

base-commit: 923de765ee1a5b26310f02cb42dcbad9e2b011c5 change-id: 20230616-sparse-flash-fix-9c2852aa8d16

Best regards,