Re: [Qemu-block] [PATCH v3 1/7] block: use 1 MB bounce buffers for crypto instead of 16KB

2017-09-16 Thread Max Reitz
On 2017-09-12 13:28, Daniel P. Berrange wrote: > Using 16KB bounce buffers creates a significant performance > penalty for I/O to encrypted volumes on storage which high > I/O latency (rotating rust & network drives), because it > triggers lots of fairly small I/O operations. > > On tests with rot

[Qemu-block] [PATCH v3 1/7] block: use 1 MB bounce buffers for crypto instead of 16KB

2017-09-12 Thread Daniel P. Berrange
Using 16KB bounce buffers creates a significant performance penalty for I/O to encrypted volumes on storage which high I/O latency (rotating rust & network drives), because it triggers lots of fairly small I/O operations. On tests with rotating rust, and cache=none|directsync, write speed increase