[U-Boot] [PATCH] drivers: block: Allow to cache 4K blocks by default

[Jan Kiszka]

On 10.12.18 05:13, Marek Vasut wrote:
> On 12/09/2018 09:55 AM, Jan Kiszka wrote:
>> The default settings of the block cache so far only allow to hold single
>> 1K blocks. However, larger filesystems tend to use 4K. Failing to cache
>> those massively degrades access performance unless you manually tune the
>> cache first. This is not desirable.
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
> 
> I submitted the same patch before [1], oddly enough it was not picked by
> Tom.

Maybe because the follow-up discussion felt like the topic didn't settle? I 
would vote for resolving this 4K think first, because it's very real. OTW: You 
patch should go in first of all, then better solutions can be developed on top.

Jan

> 
> [1]
> http://u-boot.10912.n7.nabble.com/PATCH-RFC-blk-Increase-cache-element-size-td337975.html
> 
>> ---
>>
>> My "load mmc is slow" problem reappeared on AM65xx after growing the
>> rootfs to almost 1 GB - despite an active block cache.
>>
>>   drivers/block/blkcache.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/block/blkcache.c b/drivers/block/blkcache.c
>> index 294511fcdb..1fa64989d3 100644
>> --- a/drivers/block/blkcache.c
>> +++ b/drivers/block/blkcache.c
>> @@ -24,7 +24,7 @@ struct block_cache_node {
>>   static LIST_HEAD(block_cache);
>>   
>>   static struct block_cache_stats _stats = {
>> -	.max_blocks_per_entry = 2,
>> +	.max_blocks_per_entry = 8,
>>   	.max_entries = 32
>>   };
>>   
>>
> 
> 

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