Re: WAL fsync scheduling

Bruce Momjian <pgman@candle.pha.pa.us>

From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Larry Rosenman <ler@lerctr.org>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2000-11-18T17:43:40Z
Lists: pgsql-hackers
> * Tom Lane <tgl@sss.pgh.pa.us> [001117 23:21]:
> > Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > > Other backend will see they are not the lowest
> > > WAIT_ON_FSYNC and will wait for their byte to be set to NOT_IN_COMMIT
> > > so they can then continue, knowing their data was synced.
> > 
> > How will they wait?  Without a semaphore involved, your answer must
> > be either "timed sleep" or "busy-wait loop", neither of which is
> > attractive ...
> how about sigpause, and using SIGUSR1/SIGUSR2 to wake them up ? 

Looks like a winner.

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