From owner-freebsd-hackers@FreeBSD.ORG Wed Jun 22 08:12:58 2011 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 88BB510657F0 for ; Wed, 22 Jun 2011 08:12:58 +0000 (UTC) (envelope-from sushanth_rai@yahoo.com) Received: from nm14-vm0.access.bullet.mail.sp2.yahoo.com (nm14-vm0.access.bullet.mail.sp2.yahoo.com [98.139.44.162]) by mx1.freebsd.org (Postfix) with SMTP id 664478FC12 for ; Wed, 22 Jun 2011 08:12:58 +0000 (UTC) Received: from [98.139.44.97] by nm14.access.bullet.mail.sp2.yahoo.com with NNFMP; 22 Jun 2011 07:59:06 -0000 Received: from [98.139.44.64] by tm2.access.bullet.mail.sp2.yahoo.com with NNFMP; 22 Jun 2011 07:59:06 -0000 Received: from [127.0.0.1] by omp1001.access.mail.sp2.yahoo.com with NNFMP; 22 Jun 2011 07:59:06 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 826433.54228.bm@omp1001.access.mail.sp2.yahoo.com Received: (qmail 1189 invoked by uid 60001); 22 Jun 2011 07:59:06 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1308729546; bh=qYmDzwYJyKf67xlGak+SorpqrwmCA3uPnMGQ7oahRs4=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:MIME-Version:Content-Type; b=MXKYFPLJj4wEegHDCPZ3GwLVbvUVCoPKgtl32/AocJCsQpe68L3EM8JkHxB85mZiF/uvcmvpJOT057jEd5WjFgWeS68vYy2yw2xKcN5n7opn+oa/bRMtcC94kD7XRAvaY8H5lxsohvtAuXtEVvKVXVkzvgqOSdB90q8WcM4i3lI= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:MIME-Version:Content-Type; b=yEIEbnw4EkqizlMXWeyDJVR3j6QHVz1WzS2aKTr8uN1PqA3I4xNSkJQGhdwmWL+VrxrJ9y2n4fwo8W6P/oGMw+jiS+4Hiyh/+Jg6m+1wP6o5H3ZpG4cC+OEky5w5L9pxWQ7hQLxaJZMfPVqvmr8CzRKdVTv5Xg3R124Cs9Vu9eg=; Message-ID: <357552.99021.qm@web180003.mail.gq1.yahoo.com> X-YMail-OSG: 0KcHzlkVM1moePWboitYc3NmTWu3fRU..za1fYa84aoVh.. miifwlkBuvMB7T7eUVFaXAtGHbrGGkhyZrbYXXXtTqp68KVMs.9aOQ5L3XzW eYdRXFLW.gDX.xselMvVHjtYdX79VE5ww7_vJJ4AyUxxAQG_nGKQoheOnT1_ d7cbgnhMqc8ujK8Dn08Is0k8v5Buwrbl7.fobCBy4SIR6offnDN27DwIX.._ VPpJtkBMxRlr16DulxoVJKQShsw7C5iQp6KH_kP1T27qXRy_WnNRKJ.k_sgj buj_I_7YuZ2tkL4WCFtoPPwFb._DBk.VxcctbcJQFXN2Jrs5VX75rNFBwC42 nD54ZY5FS0jpjFEAWEMvtW1HA85HhNCEGVq5aCgNExP07vTLPOJKW3Z_LC7r SA5OpYDbvyOqs Received: from [76.211.238.91] by web180003.mail.gq1.yahoo.com via HTTP; Wed, 22 Jun 2011 00:59:06 PDT X-Mailer: YahooMailClassic/14.0.3 YahooMailWebService/0.8.111.304355 Date: Wed, 22 Jun 2011 00:59:06 -0700 (PDT) From: Sushanth Rai To: freebsd-hackers@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Subject: IPI and I/O interrupts X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 Jun 2011 08:12:58 -0000 Hi, I would like to understand little bit about the FreeBSD interrupt handling on x86. When a cpu is processing an IPI, let's say cpu is running IPI_STOP handler, are I/O interrupts like the timer interrupt disabled ? Conversely if the cpu is holding a spinlock, which means it has disabled interrupts, can it process an IPI. My understanding is executing "cli" instruction disables the maskable interrupts. I was wondering if IPIs are part of that. Thanks, Sushanth