![]() | |||||||||||||
Messages in this thread |
Nick Piggin wrote: > Andrea Arcangeli wrote: > >> On Thu, Jan 06, 2005 at 04:19:36PM +1100, Nick Piggin wrote: >> >>> This is practically what blk_congestion_wait does when the queue >>> isn't congested though, isn't it? >> >> >> >> The fundamental difference that makes it reliable is that: >> >> 1) only the I/O we're throttling against will be considered for the >> wakeup event, which means only clearing PG_writeback will be >> considered eligible for wakeup >> Currently _all_ unrelated write I/O was considered eligible >> for wakeup events and that could cause spurious oom kills. > > > I'm not entirely convinced. In Rik's case it didn't matter, because > all his writeout was in the same zone that reclaim was happening > against (ZONE_NORMAL), so in that case, PG_writeback throttling > will do exactly the same thing as blk_congestion_wait. > > I do like your PG_writeback throttling idea for the other reason > that it should behave better on NUMA systems with lots of zones > and lots of disks. > ... or Andrew's described fix. I think both would result in pretty similar behaviour, but Andrew's is probably a bit nicer because it doesn't require the scanner to have initiated the write. - 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/ | ||||||||||||
| Last update: 2005-03-22 14:09 [from the cache] ©2003-2008 | |||||||||||||