From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f53.google.com (mail-oa1-f53.google.com [209.85.160.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8DCB823EAB0 for ; Wed, 22 Apr 2026 01:11:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776820263; cv=none; b=s+PNhn3ugYBaRaF0HJCIKZSOelCuv6m896tNaT5vZaO7BY1JOqkNH8DVrA+RUc5lByxGOJCS1tpexxwI6i4sbR/W9WM7UhANfDhR9TU/i3GYhHQ77gZSuyKzuebDi8ZNm6m/UmiRrk063l5PyvVOFuZ94wb4KbIhJHqy7T5CRgk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776820263; c=relaxed/simple; bh=DUKgx1rCLE6m0SecaQACluSgGEikDeAjV1aFQ/pVo18=; h=Mime-Version:Content-Type:Date:Message-Id:Cc:Subject:From:To: References:In-Reply-To; b=SbNIkw1t20YEIVlEmzZNWEwEWKQUTfhG9tf8IOCOBXyvvq5jq1m7IJ+z9o6JP5bXVC0smthSKrN5SVgYggmLIjpEfqs6M5GKcN9JpW1qcf5Y2JbHmbGItmpOj88760VVioP/vKRPTd7hIExpJISoQcTgoP5c8YUx++SlEAHDULY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=rpemtFLH; arc=none smtp.client-ip=209.85.160.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rpemtFLH" Received: by mail-oa1-f53.google.com with SMTP id 586e51a60fabf-40ee9b945d5so3855492fac.0 for ; Tue, 21 Apr 2026 18:11:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1776820261; x=1777425061; darn=vger.kernel.org; h=in-reply-to:references:to:from:subject:cc:message-id:date :content-transfer-encoding:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=l4KKy+GeCNYRz5/9NiO9N9jwB8Q0FzgbWoQqLXr4fGM=; b=rpemtFLHxwVT9Vaw9DgNw0Ss3zadVySCaJ0yE8CkNU0/6DY2o0dOS/gA5Pr15zA5bR 85hoVO0rdiwd9DUTtjuL8kylX+gXK+5sbCI9VMp1j8K+xgsH2tdm/VtKFfgGUbCelP2s w8Sa4L8ifowriPNlycHgzk7lyASHjBYPN5HkkQmxyuo//Eqkk7WWfxIp5JydpU9wqDSr CQ4gmB6clzL6ld3VB4z+7k2NlY/IVTQ8/2HhHt46s4CFhx5VDZIHCugq2gd9QzzcoiRC b+6yvbBOrF5RztNYCgWJj2K9gienbwLsUUhIy+66p27I++9szzDsyX5j+mDJ7b0IEdQk O4bw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776820261; x=1777425061; h=in-reply-to:references:to:from:subject:cc:message-id:date :content-transfer-encoding:mime-version:x-gm-gg:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=l4KKy+GeCNYRz5/9NiO9N9jwB8Q0FzgbWoQqLXr4fGM=; b=Phei3nPux2Oc2uXY+3bYVZNINjgUHCxUWxdVD8fzCUjYmSunSB9F4fwycbtNIArHVv HH4Jk2sbv9MlRrPP2A3cb8OexnGcfVx2FBHLHnbh8KpcMgzHo6f9Wvc+sD9dP2j9Tqj7 JYCk4ixpeAmxvVAFCWDwoxxW7YEm4v9fMfgGcNwHUEymDijKAegFm9fvhGp0UTcCpq9C REDbX/laO/jSoKUuch6N/sD5qcM3asqOIoxzxOi85p1Oi/FyLOB+ARKnBk7iYYTYwQ+3 HOZHPtjJOVjnUWDRCocyoNK7Puda1L+/Hk9oRgEgTRCp9LkF8zMWWcHLmQYSJuj1B/62 MWoQ== X-Forwarded-Encrypted: i=1; AFNElJ+2+tu2hkjj4YpsC6zdmO0dwzfRf9adUWSL7fITAsr/xDwHaqwJA6QtmWbzK7pZOH5SlAE=@vger.kernel.org X-Gm-Message-State: AOJu0Ywh83GWbywTDnB1+ph9PQUQhoDhgEBd+7oLf+BovIFsGMaLXv6I jHY7hiIAJuJTueTz0XlhXrDFu0HX+RhaWXGF8ExfCa6QXPsA/3xUMgamSI64uA== X-Gm-Gg: AeBDievrjU2XwjfRKW9XgOPToRozNH2WfIL3j8V9M8V4zdVJ2AMrgco8MP7rhrVaBhn mIXHvA4R7IpTGvefLs4BB4yzXIHhEj+v59YVRaZDjZlSXTlFTRbeY4smcsSKZPUhGICO+uOL0jX LxwzF7CdN2GY0MU63uBORmNg4v/dOe4iE3RivHgM7a4O2UwQlTFlPpD1XSliU6NuuEpTTSIyTnu aRfG1g0VPewPhP/NN2iQ7/SZk1tBYf3aQaAXWj6XM1ad+xt81Zbe/1nSooIZeCLJXq0Iy4yRWY2 nARlEAVSI/2jVsklukS2wqxULB1Sinj+DkqU6sUOtAD04XNiJ8xCdyXq2eUaxqJ/w9f959/UGYC BS4qDNl0Cw+mMehg6PGEgp1I5+8Ml/7o0iEHbcRSUHYKDHI9fCHPDOPqerhIEvByBsX3N4yJqdc cflL1QEdSynhMeqnrFAOKdcKCYMN56n4Lis5LgQhrUsYTOxRwcpy6xHCj/gpLbKo8+5rXXth+wU b5LbPgTOkJt29FhB5YpDck/3lh+ X-Received: by 2002:a05:6870:8108:b0:41b:f7f5:e8a7 with SMTP id 586e51a60fabf-42abf2ec957mr12919832fac.15.1776820261416; Tue, 21 Apr 2026 18:11:01 -0700 (PDT) Received: from localhost ([2a03:2880:10ff:74::]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-42b934a2e8esm13931079fac.10.2026.04.21.18.10.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 21 Apr 2026 18:11:00 -0700 (PDT) Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Tue, 21 Apr 2026 18:10:59 -0700 Message-Id: Cc: "Puranjay Mohan" , "Alexei Starovoitov" , "Andrii Nakryiko" , "Daniel Borkmann" , "Martin KaFai Lau" , "Eduard Zingerman" , "Kumar Kartikeya Dwivedi" , "Mykyta Yatsenko" , "Fei Chen" , "Taruna Agrawal" , "Nikhil Dixit Limaye" , "Nikita V. Shirokov" , Subject: Re: [RFC PATCH bpf-next 2/6] selftests/bpf: Add BPF batch-timing library From: "Alexei Starovoitov" To: "Puranjay Mohan" , X-Mailer: aerc References: <20260420111726.2118636-1-puranjay@kernel.org> <20260420111726.2118636-3-puranjay@kernel.org> In-Reply-To: <20260420111726.2118636-3-puranjay@kernel.org> On Mon Apr 20, 2026 at 4:17 AM PDT, Puranjay Mohan wrote: > +#define BENCH_BPF_LOOP(body, reset) ({ \ > + __u64 __bench_start =3D bpf_get_cpu_time_counter(); \ > + int __bench_result; \ > + \ > + bpf_repeat(batch_iters) { \ > + __bench_result =3D (body); \ > + reset; \ > + } \ You're trying to save a nsec by relying on bpf_get_cpu_time_counter, but then wasting a lot more by using bpf_repeat. It should have been bpf_ktime_get_ns(). I see no value in bpf_get_cpu_time_counter() here. I bet the numbers should be the same. But please use plain loop and may_goto if necessary. For tiny (body) it may be noticeable. > + \ > + bench_record_sample(bpf_cpu_time_counter_to_ns( \ > + bpf_get_cpu_time_counter() - __bench_start)); \ > + \ > + __bench_result =3D (body); \ > + __bench_result; \ > +}) > + > +#endif /* __BENCH_BPF_TIMING_BPF_H__ */