Date: Fri, 12 Mar 2004 15:43:03 -0500 From: John Baldwin <jhb@FreeBSD.org> To: alpha@FreeBSD.org Subject: Testers Needed!! Message-ID: <200403121543.03123.jhb@FreeBSD.org>
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Ok, two patches that I need someone to test. First off, I have some fixes to allow ptrace() to be marked MP safe again w/o generating a lock order reversal. This patch is at http://www.FreeBSD.org/~jhb/patches/alpha.ptrace.patch Note that you will have to do a 'make init_sysent.c' in sys/kern after patching to get the updated ptrace flag before building a new kernel. Second patch is to enable ithread preemption on Alpha which should reduce interrupt latency and provide a noticeable performance improvement (it did on i386 when we turned it on). The last time I was playing with having this on, I would get lockups under load on my SMP test system (a DS20). I think the reason it locked up was due to migration resulting in the thread that was interrupted by an interrupt returning back to PAL on a different CPU and that this violated some assumption made by PAL. To work around this, I use the new sched_pin() API to pin the interrupted thread around ithread preemption in this patch. So, this patch needs to be tested on both UP and SMP under load (-j 256 world build loops, etc.). I'm also curious if it does help performance at all, or at least the interactive "feel". Patch is at http://www.FreeBSD.org/~jhb/patches/alpha_preempt.patch Thanks. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org
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