From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-187.mta1.migadu.com (out-187.mta1.migadu.com [95.215.58.187]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3A6824B5C1 for ; Thu, 21 Nov 2024 14:35:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.187 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732199751; cv=none; b=MCpJRiULYJoVsoGsHVIM2bn9aaWAWLRhpi3as1sfOhZe4Kofl9VCDM3AgrESeGerUPoHS06MNJX6Ko3vE4+1VaFkN5GmZOS3Dn5Es9SKUZJuBwfoVOwlBK9HKjwdmBzs3Cc8hWdU/XRIE7zb4TWEiIOX2NcS2Fn3NXHscETGO0c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732199751; c=relaxed/simple; bh=JyXn7wkLQ9cW9EoTUjDG3LcTdk6DayhCTptVALhR8b8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hobjWBuUWMafPjh5/k7PqbBMzSI/iiMuTG/NSdT44ggllVPGgMwnvDqmc9uFc/c4yJVd74UGWhTJdKQHAX/1JEsnf7JDzWlXQicLUyrOdnXpymqwCLHyNXqkpcd1lbGG32vuZbniWyxApzm+UC3dGXFaLi7h89AkfyGrCck+QvY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=i8zE/duj; arc=none smtp.client-ip=95.215.58.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="i8zE/duj" Message-ID: <482d32d5-2caa-4759-b3b1-765678ac42a2@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1732199746; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZWqqTQ7QvVcKRBwBn1GBC6WXLakVcFHdgjYGfXvoGLw=; b=i8zE/dujqOMycxCOzjPkioZQLlPtVn/qMO1wR8Zsq1SZFhcKrEw9JWBvTPnrNz4BBZm2yN KQUxqz7D1a8ie4H9yIK5bNWHcfQSo20KZxrCUwdtuPraykSshcRQQXN42SGGq60pQaIs6u aSvC8CEORxMJIjEBR1KO+LKGZzdocvw= Date: Thu, 21 Nov 2024 06:35:39 -0800 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v8 1/4] bpf: add bpf_get_cpu_time_counter kfunc To: Peter Zijlstra , Vadim Fedorenko Cc: Borislav Petkov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Thomas Gleixner , Yonghong Song , Mykola Lysenko , x86@kernel.org, bpf@vger.kernel.org, Martin KaFai Lau References: <20241121000814.3821326-1-vadfed@meta.com> <20241121000814.3821326-2-vadfed@meta.com> <20241121113202.GG24774@noisy.programming.kicks-ass.net> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Vadim Fedorenko In-Reply-To: <20241121113202.GG24774@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 21/11/2024 03:32, Peter Zijlstra wrote: > On Wed, Nov 20, 2024 at 04:08:11PM -0800, Vadim Fedorenko wrote: >> New kfunc to return ARCH-specific timecounter. For x86 BPF JIT converts >> it into rdtsc ordered call. Other architectures will get JIT >> implementation too if supported. The fallback is to >> __arch_get_hw_counter(). > > Still not a single word as to *WHY* and what you're going to do with > those values. > > NAK Did you have a chance to read cover letter?