Re: [RFC] 2.3.39 zone balancing
From: Rik van Riel <hidden>
Date: 2000-01-13 13:40:14
On Wed, 12 Jan 2000, Kanoj Sarcar wrote:
quoted hunk ↗ jump to hunk
--- mm/page_alloc.c Tue Jan 11 11:00:31 2000 +++ mm/page_alloc.c Tue Jan 11 23:59:35 2000 + cumulative += size; + mask = (cumulative >> 7); + if (mask < 1) mask = 1; + zone->pages_low = mask*2; + zone->pages_high = mask*3; zone->low_on_memory = 0;
I think that busier machines probably have a larger need for DMA memory than this code fragment will give us. I have the gut feeling that we'll want to keep about 512kB or more free in the lower 16MB of busy machines... (if only because such a large amount of free pages in such a small part of the address space will give us higher-order free pages)
quoted hunk ↗ jump to hunk
--- mm/vmscan.c Tue Jan 11 11:00:31 2000 +++ mm/vmscan.c Tue Jan 11 23:29:41 2000@@ -534,8 +534,11 @@ int retval = 1; wake_up_process(kswapd_process); - if (gfp_mask & __GFP_WAIT) + if (gfp_mask & __GFP_WAIT) { + current->flags |= PF_MEMALLOC; retval = do_try_to_free_pages(gfp_mask, zone); + current->flags &= ~PF_MEMALLOC; + } return retval; }
Please note that kswapd still exits when the total number of free pages in the system is high enough. Balancing can probably better be done in the background by kswapd than by applications that happen to stumble across a nonbalanced zone... regards, Rik -- The Internet is not a network of computers. It is a network of people. That is its real strength. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.nl.linux.org/Linux-MM/