[PATCH] lib: sparse: allocate blkcnt instead of arbitrary small number
Mattijs Korpershoek
mkorpershoek at baylibre.com
Thu Jul 6 11:43:13 CEST 2023
On lun., juin 19, 2023 at 10:21, Mattijs Korpershoek <mkorpershoek at baylibre.com> wrote:
> Hi Qianfan,
>
> Thank you for your review.
>
> On lun., juin 19, 2023 at 14:19, qianfan <qianfanguijin at 163.com> wrote:
>
>> 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/20221118121323.4009193-1-gary.bisson@boundarydevices.com
>>> [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 at baylibre.com>
>>> ---
>>> 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.
>
> I believe memory copy also affects performance, but in my case,
> it has less impact than small mmc blks.
>
> With 62649165cb02 reverted:
> Sending sparse 'super' 1/2 (768793 KB) OKAY [ 23.947s]
> Writing 'super' OKAY [ 12.983s]
> Sending sparse 'super' 2/2 (629819 KB) OKAY [ 19.600s]
> Writing 'super' OKAY [ 12.796s]
> Finished. Total time: 69.430s
>
> With aligned_buf_blks = blkcnt:
> Sending sparse 'super' 1/2 (768793 KB) OKAY [ 24.072s]
> Writing 'super' OKAY [ 16.177s]
> Sending sparse 'super' 2/2 (629819 KB) OKAY [ 19.681s]
> Writing 'super' OKAY [ 14.845s]
> Finished. Total time: 74.919s
>
>>
>> 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 clarify the concern here? I've dumped blkcnt for my board
> (AM62x SK EVK) and the biggest blkcnt I found was: 131072
>
> With info->blksz = 512, this gives me: 512 * 131072 = 67108864
>
> Which is a memalign (memory alloc) of 64MB. Is 64MB really that big? (I
> don't realize it's that much)
>
>>
>> Could you please set aligned_buf_blks to FASTBOOT_MAX_BLK_WRITE(16384)
>> and test again?
>
> With aligned_buf_blks = FASTBOOT_MAX_BLK_WRITE(16384):
> 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
>
> So using FASTBOOT_MAX_BLK_WRITE is slightly worse than using blkcnt.
> But allocations (for blksz = 512) are smaller: 8MB instead of 64MB in my example.
>
> I can spin up a v2 with FASTBOOT_MAX_BLK_WRITE but i'm waiting a little
> more feedback before doing so.
Hi Marek, Tom,
What's your take on this ? Can we keep blkcnt or should I respin using
FASTBOOT_MAX_BLK_WRITE ?
I have also tested this on VIM3, on
U-Boot 2023.07-rc6-00003-g923de765ee1a:
Sending sparse 'super' 1/13 (114684 KB) OKAY [ 5.442s]
Writing 'super' OKAY [ 5.791s]
Sending sparse 'super' 2/13 (114684 KB) OKAY [ 5.706s]
Writing 'super' OKAY [ 5.607s]
Sending sparse 'super' 3/13 (114684 KB) OKAY [ 5.468s]
Writing 'super' OKAY [ 5.835s]
Sending sparse 'super' 4/13 (114684 KB) OKAY [ 5.703s]
Writing 'super' OKAY [ 5.618s]
Sending sparse 'super' 5/13 (114684 KB) OKAY [ 6.176s]
Writing 'super' OKAY [ 5.421s]
Sending sparse 'super' 6/13 (104176 KB) OKAY [ 5.204s]
Writing 'super' OKAY [ 5.199s]
Sending sparse 'super' 7/13 (108856 KB) OKAY [ 5.456s]
Writing 'super' OKAY [ 5.290s]
Sending sparse 'super' 8/13 (114684 KB) OKAY [ 6.122s]
Writing 'super' OKAY [ 5.838s]
Sending sparse 'super' 9/13 (114684 KB) OKAY [ 5.951s]
Writing 'super' OKAY [ 5.857s]
Sending sparse 'super' 10/13 (100980 KB) OKAY [ 4.902s]
Writing 'super' OKAY [ 4.749s]
Sending sparse 'super' 11/13 (114681 KB) OKAY [ 6.041s]
Writing 'super' OKAY [ 5.779s]
Sending sparse 'super' 12/13 (107212 KB) OKAY [ 5.174s]
Writing 'super' OKAY [ 6.587s]
Sending sparse 'super' 13/13 (71496 KB) OKAY [ 3.717s]
Writing 'super' OKAY [ 3.744s]
Finished. Total time: 142.578s
With this patch:
Sending sparse 'super' 1/13 (114684 KB) OKAY [ 7.149s]
Writing 'super' OKAY [ 1.639s]
Sending sparse 'super' 2/13 (114684 KB) OKAY [ 6.993s]
Writing 'super' OKAY [ 1.713s]
Sending sparse 'super' 3/13 (114684 KB) OKAY [ 7.029s]
Writing 'super' OKAY [ 1.107s]
Sending sparse 'super' 4/13 (114684 KB) OKAY [ 7.027s]
Writing 'super' OKAY [ 0.162s]
Sending sparse 'super' 5/13 (114684 KB) OKAY [ 6.930s]
Writing 'super' OKAY [ 1.643s]
Sending sparse 'super' 6/13 (104176 KB) OKAY [ 6.253s]
Writing 'super' OKAY [ 2.348s]
Sending sparse 'super' 7/13 (108856 KB) OKAY [ 6.346s]
Writing 'super' OKAY [ 0.723s]
Sending sparse 'super' 8/13 (114684 KB) OKAY [ 6.715s]
Writing 'super' OKAY [ 2.848s]
Sending sparse 'super' 9/13 (114684 KB) OKAY [ 6.888s]
Writing 'super' OKAY [ 1.928s]
Sending sparse 'super' 10/13 (100980 KB) OKAY [ 5.979s]
Writing 'super' OKAY [ 1.178s]
Sending sparse 'super' 11/13 (114681 KB) OKAY [ 6.822s]
Writing 'super' OKAY [ 2.652s]
Sending sparse 'super' 12/13 (107212 KB) OKAY [ 6.414s]
Writing 'super' OKAY [ 5.109s]
Sending sparse 'super' 13/13 (71496 KB) OKAY [ 4.238s]
Writing 'super' OKAY [ 0.252s]
Finished. Total time: 108.151s
It's probably too late for v2023.07 to pick this up but can we consider
taking it for next?
Thanks a lot
Mattijs
>
>>> uint32_t *aligned_buf = NULL;
>>>
>>> if (CONFIG_IS_ENABLED(SYS_DCACHE_OFF)) {
>>>
>>> ---
>>> base-commit: 2f4664f5c3edc55b18d8906f256a4c8e303243c0
>>> change-id: 20230616-sparse-flash-fix-9c2852aa8d16
>>>
>>> Best regards,
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