| From: | Thomas Munro <thomas(dot)munro(at)gmail(dot)com> |
|---|---|
| To: | Luca Ferrari <fluca1978(at)gmail(dot)com> |
| Cc: | Bruce Momjian <bruce(at)momjian(dot)us>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: FreeBSD UFS & fsync |
| Date: | 2021-03-12 09:33:29 |
| Message-ID: | CA+hUKG+18FSyKWx5FOSHzOjgLvp+btNGTFaj14eDJ7-W8JHtTw@mail.gmail.com |
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| Lists: | pgsql-performance |
On Fri, Mar 12, 2021 at 10:09 PM Luca Ferrari <fluca1978(at)gmail(dot)com> wrote:
> fdatasync 16269.365 ops/sec 61 usecs/op
> fsync 8471.429 ops/sec 118 usecs/op
> Non-sync'ed 8kB writes:
> write 278484.510 ops/sec 4 usecs/op
> tps = 136.963971 (excluding connections establishing)
It looks like your system is performing very badly for some other
reason, so that synchronous I/O waits are only a small proportion of
the time, and thus fsync=off doesn't speed things up very much. I'd
look into profiling the system to try to figure out what it's doing...
maybe it's suffering from super slow hypercalls for gettimeofday(), or
something like that?
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