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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=unavailable 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 EF43EC433E6 for ; Tue, 16 Feb 2021 18:35:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C19E864E2B for ; Tue, 16 Feb 2021 18:35:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229889AbhBPSe5 (ORCPT ); Tue, 16 Feb 2021 13:34:57 -0500 Received: from foss.arm.com ([217.140.110.172]:41048 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229744AbhBPSe4 (ORCPT ); Tue, 16 Feb 2021 13:34:56 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6E9811042; Tue, 16 Feb 2021 10:34:10 -0800 (PST) Received: from slackpad.fritz.box (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8FC043F73B; Tue, 16 Feb 2021 10:34:09 -0800 (PST) Date: Tue, 16 Feb 2021 18:33:09 +0000 From: Andre Przywara To: Alexandru Elisei Cc: drjones@redhat.com, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Subject: Re: [kvm-unit-tests PATCH v3 08/11] arm/arm64: gic: Split check_acked() into two functions Message-ID: <20210216183309.714dfd5b@slackpad.fritz.box> In-Reply-To: <20210129163647.91564-9-alexandru.elisei@arm.com> References: <20210129163647.91564-1-alexandru.elisei@arm.com> <20210129163647.91564-9-alexandru.elisei@arm.com> Organization: Arm Ltd. X-Mailer: Claws Mail 3.17.1 (GTK+ 2.24.31; x86_64-slackware-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, 29 Jan 2021 16:36:44 +0000 Alexandru Elisei wrote: Hi, > check_acked() has several peculiarities: is the only function among the > check_* functions which calls report() directly, it does two things > (waits for interrupts and checks for misfired interrupts) and it also > mixes printf, report_info and report calls. > > check_acked() also reports a pass and returns as soon all the target CPUs > have received interrupts, However, a CPU not having received an interrupt > *now* does not guarantee not receiving an erroneous interrupt if we wait > long enough. > > Rework the function by splitting it into two separate functions, each with > a single responsibility: wait_for_interrupts(), which waits for the > expected interrupts to fire, and check_acked() which checks that interrupts > have been received as expected. > > wait_for_interrupts() also waits an extra 100 milliseconds after the > expected interrupts have been received in an effort to make sure we don't > miss misfiring interrupts. > > Splitting check_acked() into two functions will also allow us to > customize the behavior of each function in the future more easily > without using an unnecessarily long list of arguments for check_acked(). > > CC: Andre Przywara > Signed-off-by: Alexandru Elisei It's a good idea to split those two steps up, and to leave the actual report to the caller. Acked-by: Andre Przywara Cheers, Andre > --- > arm/gic.c | 74 ++++++++++++++++++++++++++++++++++++------------------- > 1 file changed, 48 insertions(+), 26 deletions(-) > > diff --git a/arm/gic.c b/arm/gic.c > index af4d4645c0ae..2c96cf49ce8c 100644 > --- a/arm/gic.c > +++ b/arm/gic.c > @@ -61,41 +61,43 @@ static void stats_reset(void) > } > } > > -static void check_acked(const char *testname, cpumask_t *mask) > +static void wait_for_interrupts(cpumask_t *mask) > { > - int missing = 0, extra = 0, unexpected = 0; > int nr_pass, cpu, i; > - bool bad = false; > > /* Wait up to 5s for all interrupts to be delivered */ > - for (i = 0; i < 50; ++i) { > + for (i = 0; i < 50; i++) { > mdelay(100); > nr_pass = 0; > for_each_present_cpu(cpu) { > + /* > + * A CPU having received more than one interrupts will > + * show up in check_acked(), and no matter how long we > + * wait it cannot un-receive it. Consider at least one > + * interrupt as a pass. > + */ > nr_pass += cpumask_test_cpu(cpu, mask) ? > - acked[cpu] == 1 : acked[cpu] == 0; > - smp_rmb(); /* pairs with smp_wmb in ipi_handler */ > - > - if (bad_sender[cpu] != -1) { > - printf("cpu%d received IPI from wrong sender %d\n", > - cpu, bad_sender[cpu]); > - bad = true; > - } > - > - if (bad_irq[cpu] != -1) { > - printf("cpu%d received wrong irq %d\n", > - cpu, bad_irq[cpu]); > - bad = true; > - } > + acked[cpu] >= 1 : acked[cpu] == 0; > } > + > if (nr_pass == nr_cpus) { > - report(!bad, "%s", testname); > if (i) > - report_info("took more than %d ms", i * 100); > + report_info("interrupts took more than %d ms", i * 100); > + /* Wait for unexpected interrupts to fire */ > + mdelay(100); > return; > } > } > > + report_info("interrupts timed-out (5s)"); > +} > + > +static bool check_acked(cpumask_t *mask) > +{ > + int missing = 0, extra = 0, unexpected = 0; > + bool pass = true; > + int cpu; > + > for_each_present_cpu(cpu) { > if (cpumask_test_cpu(cpu, mask)) { > if (!acked[cpu]) > @@ -106,11 +108,28 @@ static void check_acked(const char *testname, cpumask_t *mask) > if (acked[cpu]) > ++unexpected; > } > + smp_rmb(); /* pairs with smp_wmb in ipi_handler */ > + > + if (bad_sender[cpu] != -1) { > + report_info("cpu%d received IPI from wrong sender %d", > + cpu, bad_sender[cpu]); > + pass = false; > + } > + > + if (bad_irq[cpu] != -1) { > + report_info("cpu%d received wrong irq %d", > + cpu, bad_irq[cpu]); > + pass = false; > + } > + } > + > + if (missing || extra || unexpected) { > + report_info("ACKS: missing=%d extra=%d unexpected=%d", > + missing, extra, unexpected); > + pass = false; > } > > - report(false, "%s", testname); > - report_info("Timed-out (5s). ACKS: missing=%d extra=%d unexpected=%d", > - missing, extra, unexpected); > + return pass; > } > > static void check_spurious(void) > @@ -299,7 +318,8 @@ static void ipi_test_self(void) > cpumask_clear(&mask); > cpumask_set_cpu(smp_processor_id(), &mask); > gic->ipi.send_self(); > - check_acked("IPI: self", &mask); > + wait_for_interrupts(&mask); > + report(check_acked(&mask), "Interrupts received"); > report_prefix_pop(); > } > > @@ -314,7 +334,8 @@ static void ipi_test_smp(void) > for (i = smp_processor_id() & 1; i < nr_cpus; i += 2) > cpumask_clear_cpu(i, &mask); > gic_ipi_send_mask(IPI_IRQ, &mask); > - check_acked("IPI: directed", &mask); > + wait_for_interrupts(&mask); > + report(check_acked(&mask), "Interrupts received"); > report_prefix_pop(); > > report_prefix_push("broadcast"); > @@ -322,7 +343,8 @@ static void ipi_test_smp(void) > cpumask_copy(&mask, &cpu_present_mask); > cpumask_clear_cpu(smp_processor_id(), &mask); > gic->ipi.send_broadcast(); > - check_acked("IPI: broadcast", &mask); > + wait_for_interrupts(&mask); > + report(check_acked(&mask), "Interrupts received"); > report_prefix_pop(); > } >