msync with MS_ASYNC on same page broken?

[Ramneek Handa]

Hi,
I am writing a low latency application which (during the course of
processing) writes objects into a file in binary mode. I am testing
the persistence library right now which in single threaded mode can
achieve about 2 micros per record (if say 100000 records 256 bytes
each are written and i commit the entire page only once, i.e. one
commit for 100,000 records). On the other hand if i write 2 records
per commit (note there will be 16 records per page), next 15 commits
will be very slow. If on the other hand i increase my commit size to
16 per commit the speed becomes 100x.

I read the thread below and looks like the core of the problem.
http://lkml.indiana.edu/hypermail/linux/kernel/0602.1/0500.html

Can some one please shed more light on what decision was eventually
taken on this and is it already fixed (Andrew's fix seems good for
such problem)? Any other way i can get around this issue?

BTW, there is no way to predict how many records will be per
transaction/commit.

Regards,
Ramneek
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majo...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/