From nobody Mon Feb 9 09:09:53 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 516CBC77B7A for ; Fri, 2 Jun 2023 16:09:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236369AbjFBQJg (ORCPT ); Fri, 2 Jun 2023 12:09:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236561AbjFBQJ2 (ORCPT ); Fri, 2 Jun 2023 12:09:28 -0400 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50AAD132 for ; Fri, 2 Jun 2023 09:09:26 -0700 (PDT) Received: by mail-pj1-x104a.google.com with SMTP id 98e67ed59e1d1-2566b668cc5so1567374a91.0 for ; Fri, 02 Jun 2023 09:09:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1685722166; x=1688314166; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=U16a7SsqQ7yjyv5J8Y2N4u7Ylkl11H9qatwpuhmZUgo=; b=636YoGkhL1EaD07rsMfPK9rB926Ht76M8pVZszNcRp8cSFBaHFxW4ESJErvKH1m1wQ b8SVVb+49Lm4c7lpuGUxvabzksatMUh3aHtTfXuucGjqsfAbB7x8jB5X+IIkfWd/B+pM hI1Jypk91JlkfEFB2dbGzi8Bjd9QmphZBvbPzeFfXopwyd64oFIEk7hcFeTi49fzsYb0 jMhjapC0h8n44W4QCQ7q/RI4lKIJPywJjobPFbGliUK4+jwpyLj3v9rdAbRrHTavotzv jSbTLKdo3Rd++6WRrKKX3ZluUSmLDy9wL6sxwwb/x/fXUrLPPNX7BCJ2JivFRXiwGY+V XR9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685722166; x=1688314166; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=U16a7SsqQ7yjyv5J8Y2N4u7Ylkl11H9qatwpuhmZUgo=; b=j8TsfQiCqClzJoCwWB0J6H0nT2RL3YDiL48roj3ah1+OPLhSgYfArdzeYpbSCGNRAq LsM65gYyRL5mCKSDnaF8k7CcSb1uJBy8wDMOsiuC0Yx/BJ2lIxQ0Chgr97cyQwjG252t Ubyi99NpXpbkCUZkzSvpTSw8eeWDPhMTQBL6k2+nBRM2d61ex0Cl/ABKnk7DaAUFKcet RjMKYMNlAdr3Qf038gPhYwEYojYLb5LcjtRzyy60kFR3d4e4qFr0qivYuZfUQFIyvhWF Md6N+ruPaSrdDRreIRyks0ib2o8Zhe5omtbN//8ygPpAKKp0gVJH562hDASeYZHUNMwa 35ag== X-Gm-Message-State: AC+VfDz5GVzUhSVwpfw2H3L7kR5UsoBBW3pS7AFqGZZ+A4ugNSoB0U6A 20ReweYnPLmFLWXzrqFvHwKr0Rvy6QTc X-Google-Smtp-Source: ACHHUZ5ZPLDaNjdv6ql0/d9oDMUgHRd2fE1fBqzKriMYD3yXbiA53bpGux4rVDyMUkeRamgRC/kjMfQm5qU6 X-Received: from vipin.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:479f]) (user=vipinsh job=sendgmr) by 2002:a17:90a:de04:b0:24e:18ff:5bad with SMTP id m4-20020a17090ade0400b0024e18ff5badmr42850pjv.0.1685722165847; Fri, 02 Jun 2023 09:09:25 -0700 (PDT) Date: Fri, 2 Jun 2023 09:09:01 -0700 In-Reply-To: <20230602160914.4011728-1-vipinsh@google.com> Mime-Version: 1.0 References: <20230602160914.4011728-1-vipinsh@google.com> X-Mailer: git-send-email 2.41.0.rc0.172.g3f132b7071-goog Message-ID: <20230602160914.4011728-4-vipinsh@google.com> Subject: [PATCH v2 03/16] KVM: selftests: Pass the count of read and write accesses from guest to host From: Vipin Sharma To: maz@kernel.org, oliver.upton@linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, chenhuacai@kernel.org, aleksandar.qemu.devel@gmail.com, tsbogend@alpha.franken.de, anup@brainfault.org, atishp@atishpatra.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, seanjc@google.com, pbonzini@redhat.com, dmatlack@google.com, ricarkol@google.com Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kselftest@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Vipin Sharma Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Pass the number of read and write accesses done in the memstress guest code to userspace. These counts will provide a way to measure vCPUs performance during memstress and dirty logging related tests. For example, in dirty_log_perf_test this can be used to measure how much progress vCPUs are able to do while VMM is getting and clearing dirty logs. In dirty_log_perf_test, each vCPU runs once and then waits until iteration value is incremented by main thread, therefore, these access counts will not provide much useful information except for observing read vs write counts. However, in future commits, dirty_log_perf_test behavior will be changed to allow vCPUs to execute independent of userspace iterations. This will mimic real world workload where guest keeps on executing while VMM is collecting and clearing dirty logs separately. With read and write accesses known for each vCPU, impact of get and clear dirty log APIs can be quantified. Note that access counts will not be 100% reliable in knowing vCPUs performances. Few things which can affect vCPU progress: 1. vCPUs are scheduled less by host 2. Userspace operations run for longer time which end up giving vCPUs more time to execute. Signed-off-by: Vipin Sharma --- tools/testing/selftests/kvm/lib/memstress.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/memstress.c b/tools/testing/se= lftests/kvm/lib/memstress.c index 5f1d3173c238..ac53cc6e36d7 100644 --- a/tools/testing/selftests/kvm/lib/memstress.c +++ b/tools/testing/selftests/kvm/lib/memstress.c @@ -49,6 +49,8 @@ void memstress_guest_code(uint32_t vcpu_idx) struct memstress_args *args =3D &memstress_args; struct memstress_vcpu_args *vcpu_args =3D &args->vcpu_args[vcpu_idx]; struct guest_random_state rand_state; + uint64_t write_access; + uint64_t read_access; uint64_t gva; uint64_t pages; uint64_t addr; @@ -64,6 +66,8 @@ void memstress_guest_code(uint32_t vcpu_idx) GUEST_ASSERT(vcpu_args->vcpu_idx =3D=3D vcpu_idx); =20 while (true) { + write_access =3D 0; + read_access =3D 0; for (i =3D 0; i < pages; i++) { if (args->random_access) page =3D guest_random_u32(&rand_state) % pages; @@ -72,13 +76,16 @@ void memstress_guest_code(uint32_t vcpu_idx) =20 addr =3D gva + (page * args->guest_page_size); =20 - if (guest_random_u32(&rand_state) % 100 < args->write_percent) + if (guest_random_u32(&rand_state) % 100 < args->write_percent) { *(uint64_t *)addr =3D 0x0123456789ABCDEF; - else + write_access++; + } else { READ_ONCE(*(uint64_t *)addr); + read_access++; + } } =20 - GUEST_SYNC(1); + GUEST_SYNC_ARGS(1, read_access, write_access, 0, 0); } } =20 --=20 2.41.0.rc0.172.g3f132b7071-goog