From owner-freebsd-bugs@FreeBSD.ORG Mon Jun 6 11:50:12 2011 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D8BC51065673 for ; Mon, 6 Jun 2011 11:50:12 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id B63918FC12 for ; Mon, 6 Jun 2011 11:50:12 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.4/8.14.4) with ESMTP id p56BoCHL080756 for ; Mon, 6 Jun 2011 11:50:12 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.4/8.14.4/Submit) id p56BoCBd080755; Mon, 6 Jun 2011 11:50:12 GMT (envelope-from gnats) Resent-Date: Mon, 6 Jun 2011 11:50:12 GMT Resent-Message-Id: <201106061150.p56BoCBd080755@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, "Dmitry V. Krivenok" Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A29DC106566B for ; Mon, 6 Jun 2011 11:43:39 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from red.freebsd.org (red.freebsd.org [IPv6:2001:4f8:fff6::22]) by mx1.freebsd.org (Postfix) with ESMTP id 885818FC1D for ; Mon, 6 Jun 2011 11:43:39 +0000 (UTC) Received: from red.freebsd.org (localhost [127.0.0.1]) by red.freebsd.org (8.14.4/8.14.4) with ESMTP id p56BhddL021825 for ; Mon, 6 Jun 2011 11:43:39 GMT (envelope-from nobody@red.freebsd.org) Received: (from nobody@localhost) by red.freebsd.org (8.14.4/8.14.4/Submit) id p56Bhdbk021809; Mon, 6 Jun 2011 11:43:39 GMT (envelope-from nobody) Message-Id: <201106061143.p56Bhdbk021809@red.freebsd.org> Date: Mon, 6 Jun 2011 11:43:39 GMT From: "Dmitry V. Krivenok" To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: kern/157657: ksched_setscheduler interprets TS priority as RT priority X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Jun 2011 11:50:12 -0000 >Number: 157657 >Category: kern >Synopsis: ksched_setscheduler interprets TS priority as RT priority >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Mon Jun 06 11:50:12 UTC 2011 >Closed-Date: >Last-Modified: >Originator: Dmitry V. Krivenok >Release: CURRENT >Organization: >Environment: FreeBSD csx-spb-freebsd9.sspg.lab.emc.com 9.0-CURRENT FreeBSD 9.0-CURRENT #0 r222722M: Mon Jun 6 14:31:25 MSD 2011 root@csx-spb-freebsd9.sspg.lab.emc.com:/usr/obj/usr/src/sys/GENERIC amd64 >Description: At line 209 of ksched_setscheduler function TS priority is interpreted as RT priority: 205 case SCHED_OTHER: 206 if (param->sched_priority >= 0 && 207 param->sched_priority <= (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE)) { 208 rtp.type = RTP_PRIO_NORMAL; 209 rtp.prio = p4prio_to_rtpprio(param->sched_priority); 210 rtp_to_pri(&rtp, td); 211 } else 212 e = EINVAL; I think that p4prio_to_tsprio should be used instead of p4prio_to_rtpprio. >How-To-Repeat: Compile the following program: gcc -Wall setscheduler_bug.c -o setscheduler_bug #include #include #include #include #include #include #include #include int main(int argc, char** argv) { int r; struct sched_param param; assert(argc == 2); r = sched_getscheduler(getpid()); assert(r != -1); printf("Initial policy: %d\n", r); r = sched_getparam(getpid(), ¶m); assert(r != -1); printf("Initial priority: %d\n", param.sched_priority); param.sched_priority = atoi(argv[1]); r = sched_setscheduler(getpid(), SCHED_OTHER, ¶m); assert(r != -1); r = sched_getparam(getpid(), ¶m); assert(r != -1); printf("New priority: %d\n", param.sched_priority); return 0; } and run it with root permissions: $ sudo ./setscheduler_bug 32 Initial policy: 2 Initial priority: 100 New priority: 100 $ sudo ./setscheduler_bug 0 Initial policy: 2 Initial priority: 100 New priority: 72 $ As you can see new priorities are wrong. >Fix: Apply the following patch and rebuild the kernel Index: sys/kern/ksched.c =================================================================== --- sys/kern/ksched.c (revision 222722) +++ sys/kern/ksched.c (working copy) @@ -206,7 +206,7 @@ if (param->sched_priority >= 0 && param->sched_priority <= (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE)) { rtp.type = RTP_PRIO_NORMAL; - rtp.prio = p4prio_to_rtpprio(param->sched_priority); + rtp.prio = p4prio_to_tsprio(param->sched_priority); rtp_to_pri(&rtp, td); } else e = EINVAL; Then run the same program again and you should see expected priorities: $ sudo ./setscheduler_bug 32 Initial policy: 2 Initial priority: 100 New priority: 32 $ sudo ./setscheduler_bug 0 Initial policy: 2 Initial priority: 100 New priority: 0 $ >Release-Note: >Audit-Trail: >Unformatted: