On Wed, Nov 14, 2007 at 07:17:51AM -0700, Matthew Wilcox wrote: > On Wed, Nov 14, 2007 at 02:07:56AM +0100, Andi Kleen wrote: > > It's not only complexity. Each new sysfs entry costs memory. > > Memory is not free. There should be always a good reason for those. > > It's not a lot of memory; it's one directory and a couple of files for > each PCI slot in the system. Even huge systems have maybe 200 slots. > In order for this to take up as much as one page of ram on a typical PC > with six slots, this would have to consume 680 bytes per directory. I > don't think sysfs is that inefficient (and if it is, maybe this feature > is not where the problem is, given the 'power' directory per device, the > 19 files per scsi device, the huge numbers of symlinks, etc). It becomes much more when someone does a find /sys. dentries are expensive. They eventually can get pruned again, but it's still costly to do that. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
