Re: [HACKERS] Fix mdsync never-ending loop problem

Heikki Linnakangas <heikki(at)enterprisedb(dot)com> writes:
> My first thought is that the cycle_ctr just adds extra complexity. The
> canceled-flag really is the key in Takahiro-san's patch, so we don't
> need the cycle_ctr anymore.

We don't have to have it in the sense of the code not working without it,
but it probably pays for itself by eliminating useless fsyncs. The
overhead for it in my proposed implementation is darn near zero in the
non-error case. Also, Takahiro-san mentioned at one point that he was
concerned to avoid useless fsyncs because of some property of the LDC
patch --- I wasn't too clear on what, but maybe he can explain.

regards, tom lane