From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from penguin.e-mind.com (penguin.e-mind.com [195.223.140.120]) by kvack.org (8.8.7/8.8.7) with ESMTP id RAA09363 for ; Mon, 4 Jan 1999 17:54:18 -0500 Date: Mon, 4 Jan 1999 23:43:26 +0100 (CET) From: Andrea Arcangeli Reply-To: Andrea Arcangeli Subject: Re: [patch] arca-vm-6, killed kswapd [Re: [patch] new-vm improvement , [Re: 2.2.0 Bug summary]] In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Alan Cox Cc: Linus Torvalds , steve@netplus.net, bredelin@ucsd.edu, sct@redhat.com, linux-kernel@vger.rutgers.edu, H.H.vanRiel@phys.uu.nl, linux-mm@kvack.org List-ID: On Mon, 4 Jan 1999, Alan Cox wrote: > Its performance properties are very interesting however. They do seem to suggest > kswapd should be more of a last resort. Steve said me now that the image test runs not fast as in arca-3 (the one before inserting my new swap_out() smart weight code), but here there are no dubits. My latest patch double performances under swap here and every thing is _far_ more fluid (I tried only on 128Mbyte of RAM though). I go to the cinema in the menatime and I tried again now with the same results... Just to allow everyone to see the difference (and to tell me if eventually I am missing something of magic ;) here is the bench I am using: #include #include main() { char *p[160]; int i, j; int count; time_t start,stop; for (j=0; j<160; j++) { p[j] = (char *) malloc(1000000); } for (count=0;count<2000;count++) { start = time(NULL); for (j=0; j<160; j++) { for (i=0; i<1000000; i++) p[j][i] = 0; } stop = time(NULL); if (count) printf("elapsed %u\n", stop-start); fflush(stdout); } } The number 160 menas that the benchmark will tell you the time in sec it takes to dirtify 160 mbyte of virtual memory in loop. It now runs in 54 sec (against 100 before) and I am writing this in the meantime without see differences with an idle system (I couldn't open pine and sort some huge folder without any kind of slowdown under the same conditions before). My I/O is _slowww__ I have _everything_ in a IDE 6mbyte/sec disk and the seek time is really a pain (note it's the HD that is slowww, I like IDE ;). I am going to revert everything except the new things that caused the benchmark to double performances and the system to go far more fluid, to arca-vm-3 (that it's reported to be the fastest vm out there by steve under misc swapping usage (the image test)). I probably leave the swap_out() smart weight code since it's really needed on low memory even if it seems that the swapout weight is causing a bit of slowdown probably because it's not tuned right now. Andrea Arcangeli -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org