From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from max.fys.ruu.nl (max.fys.ruu.nl [131.211.32.73]) by kvack.org (8.8.7/8.8.7) with ESMTP id RAA22180 for ; Thu, 30 Apr 1998 17:20:14 -0400 Date: Thu, 30 Apr 1998 22:57:02 +0200 (MET DST) From: Rik van Riel Reply-To: Rik van Riel Subject: Re: Out of VM idea In-Reply-To: <8790ootnpp.fsf@atlas.infra.CARNet.hr> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Zlatko Calusic Cc: George , Linux Kernel List , linux-mm@kvack.org List-ID: On 29 Apr 1998, Zlatko Calusic wrote: > > You can tune the buffermem & pagecache amount of memory > > in /proc/sys/vm/{buffermem,pagecache}. > > Every time before he starts compiling, and then return to old values > when he's finished? > > IMNSHO, kernel should be autotuning. How do you propose we should do this? The round-robin deallocation and on-demand allocation of buffer/user pages are somewhat auto-tuning. Maybe we should age the page cache & buffermem pages to achieve a more LRU-like discarding scheme (the buffer pages are thrown out randomly at the moment). > > But why your system has 4 MB of free memory I really > > don't know... > if (nr_free_pages > num_physpages >> 4) > return nr+1; > > With 64MB of memory, last 4MB are almost never used!!! I believe George said something about my patch, with which the number should be lower. Anyway, the freepages number should be sysctl tunable, together with kswapd agressiveness and clustering size. > MM in last kernels is not very good. True, but maybe Linus will integrate my patch, which makes the kernel behave somewhat more predictable, and which has a builtin low/high watermark so thrashing is reduced. Rik. +-------------------------------------------+--------------------------+ | Linux: - LinuxHQ MM-patches page | Scouting webmaster | | - kswapd ask-him & complain-to guy | Vries cubscout leader | | http://www.phys.uu.nl/~riel/ | | +-------------------------------------------+--------------------------+