Commit 62649165cb ("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@boundarydevices.com
[2] https://lore.kernel.org/r/all/43e4c17c-4483-ec8e-f843-9b4c5569bd18@seco.com/
Fixes: 62649165cb ("lib: sparse: Make CHUNK_TYPE_RAW buffer aligned")
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
b1aade87ca