Hi,
Thank you for your reply.
I tried your patch and report in this e-mail.
> 1. Those code paths finish up in pg_pwritev(), but it has a loop over
> 8kb writes on Windows. Does it help if we just make "zbuffer" bigger?
> How big?
This patch improves the performance.
I applied 0001-Use-bigger-writes-in-pg_pwrite_zeros-on-Windows.patch over REL_16_6.
I changed the value "zbuffer" from 2 to 32.
I measured with nclients = 1.
16.6: 453s
16.6 + patch (zbuffer = 2): 442s
16.6 + patch (zbuffer = 4): 434s
16.6 + patch (zbuffer = 8): 430s
16.6 + patch (zbuffer = 16): 429s
16.6 + patch (zbuffer = 32): 428s
Performance improved up to 8KB and remained stable after that.
> 2. While pondering the goals of posix_fallocate(), I had a
> realisation about how we might implement FileFallocate() on Windows.
> Does this idea work? Well?
This patch degrades the performance.
16.6: 453s
16.6 + patch: 479s
Regards,
Ryohei Takahashi
