From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DBA8C67790 for ; Wed, 25 Jul 2018 14:12:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB57520882 for ; Wed, 25 Jul 2018 14:12:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB57520882 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728631AbeGYPYr (ORCPT ); Wed, 25 Jul 2018 11:24:47 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:35516 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727946AbeGYPYr (ORCPT ); Wed, 25 Jul 2018 11:24:47 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w6PEARXP012040 for ; Wed, 25 Jul 2018 10:12:55 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2kerweyag7-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 25 Jul 2018 10:12:52 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 25 Jul 2018 15:11:55 +0100 Received: from b06cxnps4076.portsmouth.uk.ibm.com (9.149.109.198) by e06smtp05.uk.ibm.com (192.168.101.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 25 Jul 2018 15:11:52 +0100 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w6PEBpmN39714856 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 25 Jul 2018 14:11:51 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D4E3642054; Wed, 25 Jul 2018 17:12:05 +0100 (BST) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5A48542061; Wed, 25 Jul 2018 17:12:05 +0100 (BST) Received: from rapoport-lnx (unknown [9.148.8.110]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Wed, 25 Jul 2018 17:12:05 +0100 (BST) Date: Wed, 25 Jul 2018 17:11:48 +0300 From: Mike Rapoport To: Thiago Jung Bauermann Cc: linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Shuah Khan , Andrea Arcangeli , Prakash Sangappa Subject: Re: [PATCH 2/3] userfaultfd: selftest: Skip test if a feature isn't supported References: <20180725024209.32586-1-bauerman@linux.ibm.com> <20180725024209.32586-3-bauerman@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180725024209.32586-3-bauerman@linux.ibm.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-TM-AS-GCONF: 00 x-cbid: 18072514-0020-0000-0000-000002AB03E0 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18072514-0021-0000-0000-000020F79E3E Message-Id: <20180725141148.GD25188@rapoport-lnx> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-07-25_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807250153 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Tue, Jul 24, 2018 at 11:42:08PM -0300, Thiago Jung Bauermann wrote: > If userfaultfd runs on a system that doesn't support some feature it is > trying to test, it currently ends with error code 1 which indicates > test failure: > > # ./userfaultfd anon 10 10 > nr_pages: 160, nr_pages_per_cpu: 80 > bounces: 9, mode: rnd poll, userfaults: 7 59 > bounces: 8, mode: poll, userfaults: 0 0 > bounces: 7, mode: rnd racing ver, userfaults: 45 2 > bounces: 6, mode: racing ver, userfaults: 3 1 > bounces: 5, mode: rnd ver, userfaults: 55 32 > bounces: 4, mode: ver, userfaults: 69 0 > bounces: 3, mode: rnd racing, userfaults: 1 1 > bounces: 2, mode: racing, userfaults: 65 0 > bounces: 1, mode: rnd, userfaults: 44 1 > bounces: 0, mode:, userfaults: 3 2 > testing UFFDIO_ZEROPAGE: done. > testing signal delivery: UFFDIO_API > # echo $? > 1 > > Make the testcase return KSFT_SKIP instead, which is more accurate since it > is not a real test failure: > > # ./userfaultfd anon 10 10 > nr_pages: 160, nr_pages_per_cpu: 80 > bounces: 9, mode: rnd poll, userfaults: 3 0 > bounces: 8, mode: poll, userfaults: 6 1 > bounces: 7, mode: rnd racing ver, userfaults: 3 1 > bounces: 6, mode: racing ver, userfaults: 2 1 > bounces: 5, mode: rnd ver, userfaults: 2 1 > bounces: 4, mode: ver, userfaults: 3 47 > bounces: 3, mode: rnd racing, userfaults: 38 0 > bounces: 2, mode: racing, userfaults: 4 61 > bounces: 1, mode: rnd, userfaults: 16 6 > bounces: 0, mode:, userfaults: 55 25 > testing UFFDIO_ZEROPAGE: done. > testing signal delivery: UFFDIO_API: Invalid argument > # echo $? > 4 > > While at it, also improve the error message of the ioctl(UFFDIO_API) call. Can you please also make the test return KSFT_SKIP if userfaultfd(2) fails with ENOSYS? > Signed-off-by: Thiago Jung Bauermann > --- > tools/testing/selftests/vm/userfaultfd.c | 41 ++++++++++++++++++++++---------- > 1 file changed, 29 insertions(+), 12 deletions(-) > > diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c > index e4099afe7557..bc9ec38fbc34 100644 > --- a/tools/testing/selftests/vm/userfaultfd.c > +++ b/tools/testing/selftests/vm/userfaultfd.c > @@ -645,8 +645,11 @@ static int userfaultfd_open(int features) > uffdio_api.api = UFFD_API; > uffdio_api.features = features; > if (ioctl(uffd, UFFDIO_API, &uffdio_api)) { > - fprintf(stderr, "UFFDIO_API\n"); > - return 1; > + int errnum = errno; > + > + perror("UFFDIO_API"); > + > + return errnum == EINVAL ? KSFT_SKIP : 1; > } > if (uffdio_api.api != UFFD_API) { > fprintf(stderr, "UFFDIO_API error %Lu\n", uffdio_api.api); > @@ -852,6 +855,7 @@ static int userfaultfd_zeropage_test(void) > { > struct uffdio_register uffdio_register; > unsigned long expected_ioctls; > + int err; > > printf("testing UFFDIO_ZEROPAGE: "); > fflush(stdout); > @@ -859,8 +863,10 @@ static int userfaultfd_zeropage_test(void) > if (uffd_test_ops->release_pages(area_dst)) > return 1; > > - if (userfaultfd_open(0)) > - return 1; > + err = userfaultfd_open(0); > + if (err) > + return err; > + > uffdio_register.range.start = (unsigned long) area_dst; > uffdio_register.range.len = nr_pages * page_size; > uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING; > @@ -902,8 +908,9 @@ static int userfaultfd_events_test(void) > > features = UFFD_FEATURE_EVENT_FORK | UFFD_FEATURE_EVENT_REMAP | > UFFD_FEATURE_EVENT_REMOVE; > - if (userfaultfd_open(features)) > - return 1; > + err = userfaultfd_open(features); > + if (err) > + return err; > fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); > > uffdio_register.range.start = (unsigned long) area_dst; > @@ -961,8 +968,9 @@ static int userfaultfd_sig_test(void) > return 1; > > features = UFFD_FEATURE_EVENT_FORK|UFFD_FEATURE_SIGBUS; > - if (userfaultfd_open(features)) > - return 1; > + err = userfaultfd_open(features); > + if (err) > + return err; > fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); > > uffdio_register.range.start = (unsigned long) area_dst; > @@ -1027,8 +1035,9 @@ static int userfaultfd_stress(void) > if (!area_dst) > return 1; > > - if (userfaultfd_open(0)) > - return 1; > + err = userfaultfd_open(0); > + if (err) > + return err; > > count_verify = malloc(nr_pages * sizeof(unsigned long long)); > if (!count_verify) { > @@ -1199,8 +1208,16 @@ static int userfaultfd_stress(void) > return err; > > close(uffd); > - return userfaultfd_zeropage_test() || userfaultfd_sig_test() > - || userfaultfd_events_test(); > + > + err = userfaultfd_zeropage_test(); > + if (err) > + return err; > + > + err = userfaultfd_sig_test(); > + if (err) > + return err; > + > + return userfaultfd_events_test(); > } > > /* -- Sincerely yours, Mike. From mboxrd@z Thu Jan 1 00:00:00 1970 From: rppt at linux.vnet.ibm.com (Mike Rapoport) Date: Wed, 25 Jul 2018 17:11:48 +0300 Subject: [PATCH 2/3] userfaultfd: selftest: Skip test if a feature isn't supported In-Reply-To: <20180725024209.32586-3-bauerman@linux.ibm.com> References: <20180725024209.32586-1-bauerman@linux.ibm.com> <20180725024209.32586-3-bauerman@linux.ibm.com> Message-ID: <20180725141148.GD25188@rapoport-lnx> Hi, On Tue, Jul 24, 2018 at 11:42:08PM -0300, Thiago Jung Bauermann wrote: > If userfaultfd runs on a system that doesn't support some feature it is > trying to test, it currently ends with error code 1 which indicates > test failure: > > # ./userfaultfd anon 10 10 > nr_pages: 160, nr_pages_per_cpu: 80 > bounces: 9, mode: rnd poll, userfaults: 7 59 > bounces: 8, mode: poll, userfaults: 0 0 > bounces: 7, mode: rnd racing ver, userfaults: 45 2 > bounces: 6, mode: racing ver, userfaults: 3 1 > bounces: 5, mode: rnd ver, userfaults: 55 32 > bounces: 4, mode: ver, userfaults: 69 0 > bounces: 3, mode: rnd racing, userfaults: 1 1 > bounces: 2, mode: racing, userfaults: 65 0 > bounces: 1, mode: rnd, userfaults: 44 1 > bounces: 0, mode:, userfaults: 3 2 > testing UFFDIO_ZEROPAGE: done. > testing signal delivery: UFFDIO_API > # echo $? > 1 > > Make the testcase return KSFT_SKIP instead, which is more accurate since it > is not a real test failure: > > # ./userfaultfd anon 10 10 > nr_pages: 160, nr_pages_per_cpu: 80 > bounces: 9, mode: rnd poll, userfaults: 3 0 > bounces: 8, mode: poll, userfaults: 6 1 > bounces: 7, mode: rnd racing ver, userfaults: 3 1 > bounces: 6, mode: racing ver, userfaults: 2 1 > bounces: 5, mode: rnd ver, userfaults: 2 1 > bounces: 4, mode: ver, userfaults: 3 47 > bounces: 3, mode: rnd racing, userfaults: 38 0 > bounces: 2, mode: racing, userfaults: 4 61 > bounces: 1, mode: rnd, userfaults: 16 6 > bounces: 0, mode:, userfaults: 55 25 > testing UFFDIO_ZEROPAGE: done. > testing signal delivery: UFFDIO_API: Invalid argument > # echo $? > 4 > > While at it, also improve the error message of the ioctl(UFFDIO_API) call. Can you please also make the test return KSFT_SKIP if userfaultfd(2) fails with ENOSYS? > Signed-off-by: Thiago Jung Bauermann > --- > tools/testing/selftests/vm/userfaultfd.c | 41 ++++++++++++++++++++++---------- > 1 file changed, 29 insertions(+), 12 deletions(-) > > diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c > index e4099afe7557..bc9ec38fbc34 100644 > --- a/tools/testing/selftests/vm/userfaultfd.c > +++ b/tools/testing/selftests/vm/userfaultfd.c > @@ -645,8 +645,11 @@ static int userfaultfd_open(int features) > uffdio_api.api = UFFD_API; > uffdio_api.features = features; > if (ioctl(uffd, UFFDIO_API, &uffdio_api)) { > - fprintf(stderr, "UFFDIO_API\n"); > - return 1; > + int errnum = errno; > + > + perror("UFFDIO_API"); > + > + return errnum == EINVAL ? KSFT_SKIP : 1; > } > if (uffdio_api.api != UFFD_API) { > fprintf(stderr, "UFFDIO_API error %Lu\n", uffdio_api.api); > @@ -852,6 +855,7 @@ static int userfaultfd_zeropage_test(void) > { > struct uffdio_register uffdio_register; > unsigned long expected_ioctls; > + int err; > > printf("testing UFFDIO_ZEROPAGE: "); > fflush(stdout); > @@ -859,8 +863,10 @@ static int userfaultfd_zeropage_test(void) > if (uffd_test_ops->release_pages(area_dst)) > return 1; > > - if (userfaultfd_open(0)) > - return 1; > + err = userfaultfd_open(0); > + if (err) > + return err; > + > uffdio_register.range.start = (unsigned long) area_dst; > uffdio_register.range.len = nr_pages * page_size; > uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING; > @@ -902,8 +908,9 @@ static int userfaultfd_events_test(void) > > features = UFFD_FEATURE_EVENT_FORK | UFFD_FEATURE_EVENT_REMAP | > UFFD_FEATURE_EVENT_REMOVE; > - if (userfaultfd_open(features)) > - return 1; > + err = userfaultfd_open(features); > + if (err) > + return err; > fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); > > uffdio_register.range.start = (unsigned long) area_dst; > @@ -961,8 +968,9 @@ static int userfaultfd_sig_test(void) > return 1; > > features = UFFD_FEATURE_EVENT_FORK|UFFD_FEATURE_SIGBUS; > - if (userfaultfd_open(features)) > - return 1; > + err = userfaultfd_open(features); > + if (err) > + return err; > fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); > > uffdio_register.range.start = (unsigned long) area_dst; > @@ -1027,8 +1035,9 @@ static int userfaultfd_stress(void) > if (!area_dst) > return 1; > > - if (userfaultfd_open(0)) > - return 1; > + err = userfaultfd_open(0); > + if (err) > + return err; > > count_verify = malloc(nr_pages * sizeof(unsigned long long)); > if (!count_verify) { > @@ -1199,8 +1208,16 @@ static int userfaultfd_stress(void) > return err; > > close(uffd); > - return userfaultfd_zeropage_test() || userfaultfd_sig_test() > - || userfaultfd_events_test(); > + > + err = userfaultfd_zeropage_test(); > + if (err) > + return err; > + > + err = userfaultfd_sig_test(); > + if (err) > + return err; > + > + return userfaultfd_events_test(); > } > > /* -- Sincerely yours, Mike. -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: rppt@linux.vnet.ibm.com (Mike Rapoport) Date: Wed, 25 Jul 2018 17:11:48 +0300 Subject: [PATCH 2/3] userfaultfd: selftest: Skip test if a feature isn't supported In-Reply-To: <20180725024209.32586-3-bauerman@linux.ibm.com> References: <20180725024209.32586-1-bauerman@linux.ibm.com> <20180725024209.32586-3-bauerman@linux.ibm.com> Message-ID: <20180725141148.GD25188@rapoport-lnx> Content-Type: text/plain; charset="UTF-8" Message-ID: <20180725141148.SqMNQCen0mU3IzTjHxhCfSIE3w1RYFR2vIwDtNSBeMM@z> Hi, On Tue, Jul 24, 2018@11:42:08PM -0300, Thiago Jung Bauermann wrote: > If userfaultfd runs on a system that doesn't support some feature it is > trying to test, it currently ends with error code 1 which indicates > test failure: > > # ./userfaultfd anon 10 10 > nr_pages: 160, nr_pages_per_cpu: 80 > bounces: 9, mode: rnd poll, userfaults: 7 59 > bounces: 8, mode: poll, userfaults: 0 0 > bounces: 7, mode: rnd racing ver, userfaults: 45 2 > bounces: 6, mode: racing ver, userfaults: 3 1 > bounces: 5, mode: rnd ver, userfaults: 55 32 > bounces: 4, mode: ver, userfaults: 69 0 > bounces: 3, mode: rnd racing, userfaults: 1 1 > bounces: 2, mode: racing, userfaults: 65 0 > bounces: 1, mode: rnd, userfaults: 44 1 > bounces: 0, mode:, userfaults: 3 2 > testing UFFDIO_ZEROPAGE: done. > testing signal delivery: UFFDIO_API > # echo $? > 1 > > Make the testcase return KSFT_SKIP instead, which is more accurate since it > is not a real test failure: > > # ./userfaultfd anon 10 10 > nr_pages: 160, nr_pages_per_cpu: 80 > bounces: 9, mode: rnd poll, userfaults: 3 0 > bounces: 8, mode: poll, userfaults: 6 1 > bounces: 7, mode: rnd racing ver, userfaults: 3 1 > bounces: 6, mode: racing ver, userfaults: 2 1 > bounces: 5, mode: rnd ver, userfaults: 2 1 > bounces: 4, mode: ver, userfaults: 3 47 > bounces: 3, mode: rnd racing, userfaults: 38 0 > bounces: 2, mode: racing, userfaults: 4 61 > bounces: 1, mode: rnd, userfaults: 16 6 > bounces: 0, mode:, userfaults: 55 25 > testing UFFDIO_ZEROPAGE: done. > testing signal delivery: UFFDIO_API: Invalid argument > # echo $? > 4 > > While at it, also improve the error message of the ioctl(UFFDIO_API) call. Can you please also make the test return KSFT_SKIP if userfaultfd(2) fails with ENOSYS? > Signed-off-by: Thiago Jung Bauermann > --- > tools/testing/selftests/vm/userfaultfd.c | 41 ++++++++++++++++++++++---------- > 1 file changed, 29 insertions(+), 12 deletions(-) > > diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c > index e4099afe7557..bc9ec38fbc34 100644 > --- a/tools/testing/selftests/vm/userfaultfd.c > +++ b/tools/testing/selftests/vm/userfaultfd.c > @@ -645,8 +645,11 @@ static int userfaultfd_open(int features) > uffdio_api.api = UFFD_API; > uffdio_api.features = features; > if (ioctl(uffd, UFFDIO_API, &uffdio_api)) { > - fprintf(stderr, "UFFDIO_API\n"); > - return 1; > + int errnum = errno; > + > + perror("UFFDIO_API"); > + > + return errnum == EINVAL ? KSFT_SKIP : 1; > } > if (uffdio_api.api != UFFD_API) { > fprintf(stderr, "UFFDIO_API error %Lu\n", uffdio_api.api); > @@ -852,6 +855,7 @@ static int userfaultfd_zeropage_test(void) > { > struct uffdio_register uffdio_register; > unsigned long expected_ioctls; > + int err; > > printf("testing UFFDIO_ZEROPAGE: "); > fflush(stdout); > @@ -859,8 +863,10 @@ static int userfaultfd_zeropage_test(void) > if (uffd_test_ops->release_pages(area_dst)) > return 1; > > - if (userfaultfd_open(0)) > - return 1; > + err = userfaultfd_open(0); > + if (err) > + return err; > + > uffdio_register.range.start = (unsigned long) area_dst; > uffdio_register.range.len = nr_pages * page_size; > uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING; > @@ -902,8 +908,9 @@ static int userfaultfd_events_test(void) > > features = UFFD_FEATURE_EVENT_FORK | UFFD_FEATURE_EVENT_REMAP | > UFFD_FEATURE_EVENT_REMOVE; > - if (userfaultfd_open(features)) > - return 1; > + err = userfaultfd_open(features); > + if (err) > + return err; > fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); > > uffdio_register.range.start = (unsigned long) area_dst; > @@ -961,8 +968,9 @@ static int userfaultfd_sig_test(void) > return 1; > > features = UFFD_FEATURE_EVENT_FORK|UFFD_FEATURE_SIGBUS; > - if (userfaultfd_open(features)) > - return 1; > + err = userfaultfd_open(features); > + if (err) > + return err; > fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); > > uffdio_register.range.start = (unsigned long) area_dst; > @@ -1027,8 +1035,9 @@ static int userfaultfd_stress(void) > if (!area_dst) > return 1; > > - if (userfaultfd_open(0)) > - return 1; > + err = userfaultfd_open(0); > + if (err) > + return err; > > count_verify = malloc(nr_pages * sizeof(unsigned long long)); > if (!count_verify) { > @@ -1199,8 +1208,16 @@ static int userfaultfd_stress(void) > return err; > > close(uffd); > - return userfaultfd_zeropage_test() || userfaultfd_sig_test() > - || userfaultfd_events_test(); > + > + err = userfaultfd_zeropage_test(); > + if (err) > + return err; > + > + err = userfaultfd_sig_test(); > + if (err) > + return err; > + > + return userfaultfd_events_test(); > } > > /* -- Sincerely yours, Mike. -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html