Sorry for not mentioning this, but I'm using ext4.
About using more threads, it seems very unlikely to me that tis is going to help in a persistence model where an Append Only File is used in order to persist. All the clients will eventually write to the same file object and will get automatically serialized.
Btw as a proof of how the same filesystem will behave in a very different way check the O_SYNC test above: same ext4 filesystem, but an order of magnitude faster doing things in a way instead of in another way.
Unfortunately POSIX or not the real world kernel implementations are full of small implementations details that a programmer doing system programming is required to know to write fast code :(
About using more threads, it seems very unlikely to me that tis is going to help in a persistence model where an Append Only File is used in order to persist. All the clients will eventually write to the same file object and will get automatically serialized.
Btw as a proof of how the same filesystem will behave in a very different way check the O_SYNC test above: same ext4 filesystem, but an order of magnitude faster doing things in a way instead of in another way.
Unfortunately POSIX or not the real world kernel implementations are full of small implementations details that a programmer doing system programming is required to know to write fast code :(