From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: m68k 2.6.26-1 vs 2.4.30 comparison Date: Sun, 3 May 2009 13:08:06 +0200 Message-ID: <10f740e80905030408p38f87e09ueabc45ef98d4a88f@mail.gmail.com> References: <20090503072811.GB3179@luminet.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from ey-out-2122.google.com ([74.125.78.24]:32494 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751789AbZECLIJ convert rfc822-to-8bit (ORCPT ); Sun, 3 May 2009 07:08:09 -0400 Received: by ey-out-2122.google.com with SMTP id 9so812945eyd.37 for ; Sun, 03 May 2009 04:08:06 -0700 (PDT) In-Reply-To: <20090503072811.GB3179@luminet.net> Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: lancetag@luminet.net Cc: linux-m68k@vger.kernel.org On Sun, May 3, 2009 at 09:28, Lance Tagliapietra = wrote: > b). My custom 2.4.30 kernel size is about 750K uncompressed. With set= ting the options to > remove support for hardware that I don't have and features that I don= 't need, I still > came up with a kernel of 2.7M. =C2=A0The goal is to have the smallest= footprint kernel possible. Yeah, minimum kernel size has increased :-( > c). The 2.6.26 kernel seems to want to keep more memory free and hit = the swap much more > than the 2.4.30 kernel according to vmstat. =C2=A0Under 2.4.30 I see = the free memory go as low > as about 200K, and it will remain at that level as long as is necessa= ry. =C2=A0Under 2.6.26, > the free memory stays at about 800K, and if it drops below that, it w= ill come back to that > level relatively quickly. As memory consumption is general. I didn't do exact measurements, but 2.6 consumes ca. 1.5 MiB more on my A4000 (with 12 MiB of fast RAM). Booting and running Debian is slow, while I used to have more daemons installed, in a time the machine was actually used as a mailserver for 70 people, some of which read their email by logging in and running pine... > d). The real time clock came up on the worng month, going from 2.4.30= to 2.6.26 (or 28), > March vs April, in this case. That's an interesting one... In 2.4.30, you have both a2000_gettod() (for boot time setting), which = does: *monp =3D tod_2000.month1 * 10 + tod_2000.month2; and amiga_hwclk() (for /dev/rtc), which does: t->tm_mon =3D tod_2000.month1 * 10 + tod_2000.month2 - 1; In 2.6.29, you only have a2000_hwclk(), which does t->tm_mon =3D tod_2000.month1 * 10 + tod_2000.month2 - 1; The data returned by a2000_gettod() is converted to seconds using mktim= e(), which assumes months are in the range 1..12. amiga_hwclk() and a2000_hwclk() both use struct rtc_time. This should be similar to struct tm in , where the months are in the range 0..11. Both rtc_proc_output()/gen_rtc_proc_output() (2.4.30) and rtc_proc_show() (2.6.29) do print tm.tm_mon + 1 to make them be in the range 1..12. So at first sight, I don't see where the bug is... What does `hwlock -ur` say, on both 2.4.30 and 2.6.29? > Questions: > > e). Is there an option which tells the kernel the minimum amount of f= ree RAM to maintain > as I describe in (c) above? =C2=A0RAM is relatively precious in my m6= 8k environment, and having > 500k being held in reserve seems a bit much? Probably one of those swappiness parameters under /sys. Don't ask me which one... Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-= m68k.org In personal conversations with technical people, I call myself a hacker= =2E But when I'm talking to journalists I just say "programmer" or something li= ke that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-m68k" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html