Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 4 Nov 2001 13:57:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 4 Nov 2001 13:56:54 -0500 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:518 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Sun, 4 Nov 2001 13:56:42 -0500 Date: Sun, 4 Nov 2001 10:53:43 -0800 (PST) From: Linus Torvalds To: cc: Kernel Mailing List Subject: Re: Linux-2.4.14-pre8.. In-Reply-To: <20011104192725.A847@planetzork.spacenet> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 4 Nov 2001 jogi@planetzork.ping.de wrote: > > Is there anything else I can measure during the kernel compiles? > Are the numbers for >= -pre6 slower because of measures taken to > increase the "interactivity" / responsivness of the kernel? No, it's something else, possibly some of the sharing braindamage. > The part that looks most suspicious to me is that the results > for make -j100 vary so much ... Indeed. I don't like that part at all. That implies that some part of the code is unstable. One thing that Andrea points out is that the current VM scanning is rather unfair to active pages - if we get lots of active pages (for whatever reason), that will defeat some of the page-out aging code. Also, Andrea also suspects that when we de-activate a page in refill_inactive, we should activate it again if somebody touches it, and not make it go through the whole "activate on second reference" rigamole again. What does this patch do to the pre8 behaviour? (The first chunk just says that we _can_ unmap active pages: it's up to refill_inactive to perhaps de-activate them and free them on demand. The second chunk says that when refill_inactive() moves a page to the inactive list, it's already been "touched once", so another access will activate it again). Linus ---- diff -u --recursive pre8/linux/mm/vmscan.c linux/mm/vmscan.c --- pre8/linux/mm/vmscan.c Sun Nov 4 09:41:04 2001 +++ linux/mm/vmscan.c Sun Nov 4 10:41:59 2001 @@ -54,9 +54,11 @@ return 0; } +#if 0 /* Don't bother unmapping pages that are active */ if (PageActive(page)) return 0; +#endif /* Don't bother replenishing zones not under pressure.. */ if (!memclass(page->zone, classzone)) @@ -541,6 +543,7 @@ del_page_from_active_list(page); add_page_to_inactive_list(page); + SetPageReferenced(page); } spin_unlock(&pagemap_lru_lock); } - 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/