From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 14 Jan 2008 11:29:12 -0800 (PST) From: Christoph Lameter Subject: Re: [PATCH] Remove set_migrateflags() In-Reply-To: <20080114115503.GB32446@csn.ul.ie> Message-ID: References: <20080114115503.GB32446@csn.ul.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Mel Gorman Cc: akpm@linux-foundation.org, linux-mm@kvack.org List-ID: On Mon, 14 Jan 2008, Mel Gorman wrote: > Grouping the radix nodes into the same TLB entries as the inode and dcaches > does appear to help performance a small amount on kernbench at least. Applying > this patch showed a performance difference on elapsed time between -4.45% > and 0.23% and between -0.36% and 0.28% on total CPU time which appears to > support that position. Ahh... Okay. > > And thus setting __GFP_RECLAIMABLE > > is a bit strange. We could set SLAB_RECLAIM_ACCOUNT on radix tree slab > > creation if we want those to be placed in the reclaimable section. > > Then we are sure that the radix tree slabs are consistently placed in the > > reclaimable section and then the radix tree slabs will also be accounted as > > such. > > > > What is there right now places the pages appropriately but should they really > be accounted for as such too? I know that marking them like that will > cause SLUB to treat them differently and I don't fully understand the > implications of that. Marking them makes the slab allocators set GFP_RECLAIMABLE on all page allocator allocations for the radix tree and it will also cause the statistics to be update correspondingly. No other differences. > NAK for now. I'm still of the opinion that radix nodes should be marked > reclaimable because they are often cleaned up at the same time as slabs that > are really reclaimable. Do another version of this patch setting SLAB_RECLAIM_ACCOUNT for the radix tree? -- 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.linux-mm.org/ . Don't email: email@kvack.org