On Wed, 24 Jan 2007 14:15:10 +0900 KAMEZAWA Hiroyuki <[EMAIL PROTECTED]> wrote:
> - One for stability > When a customer constructs their detabase(Oracle), the system often goes to > oom. > This is because that the system cannot allocate DMA_ZOME memory for 32bit > device. > (USB or e100) > Not allowing to use almost all pages as page cache (for temporal use) will > be some help. > (Note: construction DB on ext3....so all writes are serialized and the > system couldn't > free page cache.) I'm surprised that any reasonable driver has a dependency on ZONE_DMA. Are you sure? Send full oom-killer output, please. > - One for tuing. > Sometimes our cutomer requests us to limit size of page-cache. > > Many cutomers's memory usage reaches 99.x%. (this is very common situation.) > If almost all memories are used by page-cache, and we can think we can free > it. > But the customer cannot estimate what amount of page-cache can be freed > (without > perfromance regression). > > When a cutomer wants to add a new application, he tunes the system. > But memory usage is always 99%. > page-cache limitation is useful when the customer tunes his system and find > sets of data and page-cache. > (Of course, we can use some other complicated resource management system > for this.) > This will allow the users to decide that they need extra memory or not. > > And...some customers want to keep memory Free as much as possible. > 99% memory usage makes insecure them ;) Tell them to do "echo 3 > /proc/sys/vm/drop_caches", then wait three minutes? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
