Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932693AbWEXLTB (ORCPT ); Wed, 24 May 2006 07:19:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932692AbWEXLTB (ORCPT ); Wed, 24 May 2006 07:19:01 -0400 Received: from smtp.ustc.edu.cn ([202.38.64.16]:31360 "HELO ustc.edu.cn") by vger.kernel.org with SMTP id S932681AbWEXLTB (ORCPT ); Wed, 24 May 2006 07:19:01 -0400 Message-ID: <348469537.16036@ustc.edu.cn> X-EYOUMAIL-SMTPAUTH: wfg@mail.ustc.edu.cn Message-Id: <20060524111858.869793445@localhost.localdomain> References: <20060524111246.420010595@localhost.localdomain> Date: Wed, 24 May 2006 19:12:50 +0800 From: Wu Fengguang To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Wu Fengguang Subject: [PATCH 04/33] readahead: page flag PG_readahead Content-Disposition: inline; filename=readahead-page-flag-PG_readahead.patch Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2036 Lines: 52 An new page flag PG_readahead is introduced as a look-ahead mark, which reminds the caller to give the adaptive read-ahead logic a chance to do read-ahead ahead of time for I/O pipelining. It roughly corresponds to `ahead_start' of the stock read-ahead logic. Signed-off-by: Wu Fengguang --- include/linux/page-flags.h | 5 +++++ mm/page_alloc.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) --- linux-2.6.17-rc4-mm3.orig/include/linux/page-flags.h +++ linux-2.6.17-rc4-mm3/include/linux/page-flags.h @@ -89,6 +89,7 @@ #define PG_reclaim 17 /* To be reclaimed asap */ #define PG_nosave_free 18 /* Free, should not be written */ #define PG_buddy 19 /* Page is free, on buddy lists */ +#define PG_readahead 20 /* Reminder to do readahead */ #if (BITS_PER_LONG > 32) @@ -372,6 +373,10 @@ extern void __mod_page_state_offset(unsi #define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags) #define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags) +#define PageReadahead(page) test_bit(PG_readahead, &(page)->flags) +#define __SetPageReadahead(page) __set_bit(PG_readahead, &(page)->flags) +#define TestClearPageReadahead(page) test_and_clear_bit(PG_readahead, &(page)->flags) + struct page; /* forward declaration */ int test_clear_page_dirty(struct page *page); --- linux-2.6.17-rc4-mm3.orig/mm/page_alloc.c +++ linux-2.6.17-rc4-mm3/mm/page_alloc.c @@ -564,7 +564,7 @@ static int prep_new_page(struct page *pa if (PageReserved(page)) return 1; - page->flags &= ~(1 << PG_uptodate | 1 << PG_error | + page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_readahead | 1 << PG_referenced | 1 << PG_arch_1 | 1 << PG_checked | 1 << PG_mappedtodisk); set_page_private(page, 0); -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/