From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 27 Feb 2004 21:11:13 -0500 (EST) From: Anand Eswaran Subject: Desperate plea Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: aeswaran@ece.cmu.edu List-ID: Hi : Sorry but kernelnewbies seems offline, you're the only source that can help me ! Pls be kind enough to respond OR if busy, pls point me out to some source which answers the question. Question -------- I'm observing the following execution path in page_launder_zone handling *anonymous* page in 2.4.18: 1) A page starts out with PageInactiveDirty(page) and page->pte_chain ON 2) After add_to_swap() , PageInactiveDirty(page), page->pte_chain, page->mapping and PageSwapCache(page) are ON 3) After try_to_unmap(), page->mapping is turned OFF 4) After that, it enters the writepage() function, after which it results in non-NULL page->buffers 5) kswapd then continues to the next page. Q1 : --- When do these buffers formed from anonymous pages in step 4 get written out to disk? I thought writepage was supposed to clean the page's buffers, so Im surprised that after the writepage() page->buffers is non-null. Q2: --- Also, if anonymous pages always result in non-NULL buffers (as in step 4 ), in the launder loop: if (page->buffers) { page_cache_get(page); spin_unlock(&pagemap_lru_lock); if (try_to_release_page(page,gfp_mask)) { if (!page->mapping) { ... why is there the need for the "if (!page->mapping)" loop? Seems like by this stage, anonymous pages already are mapped to swap_cache? I know Im missing something. Could someone pls point it out to me? Thanks a lot! ----- Anand. -- 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: aart@kvack.org