On Thu, 06 Sep 2007 14:53:01 +0100 Mel Gorman <[EMAIL PROTECTED]> wrote:
> Does it really matter as they routinely do not take zone->lru_lock > either? pages_min, pages_low and pages_high are currently examined on a > regular basis by zone_watermark_ok() without any locks held in the page > allocator and page reclaim path. Glancing through this, it would appear > that the code in question has the same level of locking protection with > zone->lru_lock or zone->lock. > At the first look, I thought this should be lock-less. But I noticed that memory hotplug(See add_memory()) calls setup_per_zone_pages_min(). Then, logically, there are 2 interfaces which calls setup_per_zone_pages_min(); So, we need some kind of lock. And setup_zone_migrate_reserve() is also called in this function. This does more than change value. So I thought zone->lock is good here. > Is memory hotadd specifically taking the lru_lock somewhere? I can only > think of the seqlock at the moment. > memory hotplug doesn't take lru_lock. Thanks, -Kame - 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/
