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.bis...@boundarydevices.com [2] https://lore.kernel.org/r/all/43e4c17c-4483-ec8e-f843-9b4c5569b...@seco.com/ Fixes: 62649165cb02 ("lib: sparse: Make CHUNK_TYPE_RAW buffer aligned") Signed-off-by: Mattijs Korpershoek <mkorpersh...@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-v1-1-6bafeacc5...@baylibre.com --- 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 + #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, -- Mattijs Korpershoek <mkorpersh...@baylibre.com>
