Messages in this thread | | | Date | Fri, 12 Dec 2003 15:24:59 +0100 | From | Jörn Engel <> | Subject | Re: Is there a "make hole" (truncate in middle) syscall? |
| |
On Fri, 12 December 2003 14:56:09 +0100, Jörn Engel wrote: > On Fri, 12 December 2003 07:39:25 -0600, Rob Landley wrote: > > On Friday 12 December 2003 06:55, Jörn Engel wrote: > > > > > > Yes, the obvious and stupid implementation has a ton of problems. > > > Most likely the right approach is some sort of background deamon > > > (garbage collector, defragmenter, journald, whatever you may call it) > > > that does exacly this even after the fact for the last unchecked > > > writes. Asyncronous under load, possibly even synchronous when almost > > > idle. > > > > Actually, I'd planned on implementing a cron job that could do it. We're > > talking a dozen lines of Python code (which can be optimized to only look at > > files with timestamps since the last time it ran). And doesn't need anything > > from the kernel but the syscall... > > ...and it sucks. Same problem as with updatedb - 99% of all work is > bogus, but you don't know which 99%, because the one knowing about it, > the kernel, doesn't tell you a thing.
Actually, updatedb sucks even worse. The database is notoriously outdated and each run of updatedb has the effect of flushing the cache. Because of the cache-flushing effect, you cannot even run it with maximum niceness. Running it still hurts you *afterwards*.
Same goes for you userland daemon without kernel support.
Jörn
-- To recognize individual spam features you have to try to get into the mind of the spammer, and frankly I want to spend as little time inside the minds of spammers as possible. -- Paul Graham - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |