From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 3F610254861 for ; Fri, 28 Feb 2025 16:43:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740761030; cv=none; b=pIvFFwxMij4bKAINB7cWwsPwKM1DcRFVX50kBIK4b13CZnrADaPKQGbhJYwr+XxsTJLTLB7rMqtCeQ3ot55VFWs7DUJtR+6nz9/6CREvbuwA9M+zLLE2QxRO3eQZXlNwvErd8raCaT2JhcZokRMWFBDCprfpBQ4HYzEkog4OLqA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740761030; c=relaxed/simple; bh=wvv9KqhZwUsWb+lgfSj2l4+bwKH8+JdHivJEOBV4+Ys=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=b90fZp2dijku/ZG+ig57JiU2hr6Z7s/fUNYMumf3YtOsBLsCz70Wla6QeodpW5yzKfJWoPZ1GmlCY+cl4UPDOV1WVzt3SljWqyk7JuyYlPowQjveQf5CbhpN2e60gemg03pUuppHFTYvT2snzgdQXyv/aw7Y6/uPookTQBbZbWI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=MFU3hWdh; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MFU3hWdh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740761028; 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:autocrypt:autocrypt; bh=F0QGo9HdSucNqODk69QyhyvARJ/ftblyHDK9MmTLa3Q=; b=MFU3hWdh3X/HvaS6KU0UBuFbBKkyBrwmcYB0ePRzF8WnHsCF3BcY7xkdHNBgLDeaHaZBGp UfbACa54bFLu3RWHQAWGC2GIZByoR1hTHKEWICEbo2wobOgLtwfDRVjnwqva8tJvMRmgRd 9ZS313azE4VfOBaCRTqqcR/bOklKDUY= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-433-U-1xbCGQMVarsGdeXKwKiQ-1; Fri, 28 Feb 2025 11:43:46 -0500 X-MC-Unique: U-1xbCGQMVarsGdeXKwKiQ-1 X-Mimecast-MFC-AGG-ID: U-1xbCGQMVarsGdeXKwKiQ_1740761026 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-390e271517fso1339250f8f.1 for ; Fri, 28 Feb 2025 08:43:46 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740761025; x=1741365825; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :from:references:cc:to:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=F0QGo9HdSucNqODk69QyhyvARJ/ftblyHDK9MmTLa3Q=; b=mIx4DLM/myDL10c+AKDnnU2C9J8CuUVYEHazwz5pEx2O5VSkMcaPRuKswg7lgd970V L6HVD7ipvK719aatTSb0QeU1moU3w8VXiOGez1W1kO8lsIulf8/+Q4oyBrdS0zzsiQeE d7SvlgfcNumC3qb/8G2gd/xujHY6PD26BAcqRgvdUI9851AoVf4gB8vOxbvwaVrVf79+ 9swR2tuf4w9SgYKZ5Y40xqRn2l6fNquwoGStj19h+OnYWwPzLshTZQBl0oFRiTrqOuj8 E2KSk+w3Mthhj6h1nZH4YocOS+RA20LzRyYFm57C6cxdGNg2esH4WzXGR+ejuRZJ707w P/0A== X-Forwarded-Encrypted: i=1; AJvYcCX+EL8ohHv70q8o/sphQNGPAV6F3pLuZjV0eAGGbMULqY+TMT10SSd/YOnRyLijyuvEsw2fFvo=@vger.kernel.org X-Gm-Message-State: AOJu0YxUcF3L+nP2+5ZqvyA1T9WKrFJP+frZD2dFgWcgjPQPByoyNOja kt4FYBSVsAZYpEASmieYanUZnLnHLXfBG00Qg9Tn/o2OpCCbMf62G3KnTIrtPpvLuCPe44tdsHf N7Hui1qNaEyX9rtijFzYsGtGe5fdVhmIwLiMTF4kj7CZflr2oCPqFfQ== X-Gm-Gg: ASbGnctJ1nMHOhf+lotE+ZS4dFFUF03X0RwpyV3F1SPkION/SAcU/Q+0tbye7Dyvjrm HXCwrZkodfrKH0xsKU0k5u4XgTW6flWsIL+E7Kgh5IGSm8sXfra7c0spRU/eZHvvfY/Gk6XiUHO sxRO78zuukFfsPfBjiXk+bJ4/oIHH8yO5xC0MQvGPjclkdwVbE4ilDUrHIGKO37msWO0n8Ll7rA ZV/WQd0+IjCBDHDhv7LEXjOsAI09ismP9IpNFXEo01JIHr7WbAsDVrJj6kqQSHhsJUQvjosVPko Mfz72s9xJQUoKe84uNS+ X-Received: by 2002:a05:6000:1a8d:b0:390:e7d7:9669 with SMTP id ffacd0b85a97d-390ec7ccfb4mr4812436f8f.21.1740761025572; Fri, 28 Feb 2025 08:43:45 -0800 (PST) X-Google-Smtp-Source: AGHT+IFM+V0QFUXYyh2cfMC6RxPcJOHS8+pixnyA7NNsa8i7lZq3JzDKV8Sj/QMZTwmon1bEt2pH3g== X-Received: by 2002:a05:6000:1a8d:b0:390:e7d7:9669 with SMTP id ffacd0b85a97d-390ec7ccfb4mr4812401f8f.21.1740761025137; Fri, 28 Feb 2025 08:43:45 -0800 (PST) Received: from [192.168.10.48] ([151.95.152.199]) by smtp.googlemail.com with ESMTPSA id ffacd0b85a97d-390e4844adfsm5742245f8f.62.2025.02.28.08.43.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 28 Feb 2025 08:43:44 -0800 (PST) Message-ID: <3b1046fb-962c-4c15-9c4e-9356171532a0@redhat.com> Date: Fri, 28 Feb 2025 17:43:43 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCHv3 0/2] To: Keith Busch , Sean Christopherson Cc: Lei Yang , Keith Busch , kvm@vger.kernel.org, virtualization@lists.linux.dev, x86@kernel.org, netdev@vger.kernel.org References: <20250227230631.303431-1-kbusch@meta.com> From: Paolo Bonzini Content-Language: en-US Autocrypt: addr=pbonzini@redhat.com; keydata= xsEhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAc0j UGFvbG8gQm9uemluaSA8cGJvbnppbmlAcmVkaGF0LmNvbT7CwU0EEwECACMFAlRCcBICGwMH CwkIBwMCAQYVCAIJCgsEFgIDAQIeAQIXgAAKCRB+FRAMzTZpsbceDp9IIN6BIA0Ol7MoB15E 11kRz/ewzryFY54tQlMnd4xxfH8MTQ/mm9I482YoSwPMdcWFAKnUX6Yo30tbLiNB8hzaHeRj jx12K+ptqYbg+cevgOtbLAlL9kNgLLcsGqC2829jBCUTVeMSZDrzS97ole/YEez2qFpPnTV0 VrRWClWVfYh+JfzpXmgyhbkuwUxNFk421s4Ajp3d8nPPFUGgBG5HOxzkAm7xb1cjAuJ+oi/K CHfkuN+fLZl/u3E/fw7vvOESApLU5o0icVXeakfSz0LsygEnekDbxPnE5af/9FEkXJD5EoYG SEahaEtgNrR4qsyxyAGYgZlS70vkSSYJ+iT2rrwEiDlo31MzRo6Ba2FfHBSJ7lcYdPT7bbk9 AO3hlNMhNdUhoQv7M5HsnqZ6unvSHOKmReNaS9egAGdRN0/GPDWr9wroyJ65ZNQsHl9nXBqE AukZNr5oJO5vxrYiAuuTSd6UI/xFkjtkzltG3mw5ao2bBpk/V/YuePrJsnPFHG7NhizrxttB nTuOSCMo45pfHQ+XYd5K1+Cv/NzZFNWscm5htJ0HznY+oOsZvHTyGz3v91pn51dkRYN0otqr bQ4tlFFuVjArBZcapSIe6NV8C4cEiSTOwE0EVEJx7gEIAMeHcVzuv2bp9HlWDp6+RkZe+vtl KwAHplb/WH59j2wyG8V6i33+6MlSSJMOFnYUCCL77bucx9uImI5nX24PIlqT+zasVEEVGSRF m8dgkcJDB7Tps0IkNrUi4yof3B3shR+vMY3i3Ip0e41zKx0CvlAhMOo6otaHmcxr35sWq1Jk tLkbn3wG+fPQCVudJJECvVQ//UAthSSEklA50QtD2sBkmQ14ZryEyTHQ+E42K3j2IUmOLriF dNr9NvE1QGmGyIcbw2NIVEBOK/GWxkS5+dmxM2iD4Jdaf2nSn3jlHjEXoPwpMs0KZsgdU0pP JQzMUMwmB1wM8JxovFlPYrhNT9MAEQEAAcLBMwQYAQIACQUCVEJx7gIbDAAKCRB+FRAMzTZp sadRDqCctLmYICZu4GSnie4lKXl+HqlLanpVMOoFNnWs9oRP47MbE2wv8OaYh5pNR9VVgyhD OG0AU7oidG36OeUlrFDTfnPYYSF/mPCxHttosyt8O5kabxnIPv2URuAxDByz+iVbL+RjKaGM GDph56ZTswlx75nZVtIukqzLAQ5fa8OALSGum0cFi4ptZUOhDNz1onz61klD6z3MODi0sBZN Aj6guB2L/+2ZwElZEeRBERRd/uommlYuToAXfNRdUwrwl9gRMiA0WSyTb190zneRRDfpSK5d usXnM/O+kr3Dm+Ui+UioPf6wgbn3T0o6I5BhVhs4h4hWmIW7iNhPjX1iybXfmb1gAFfjtHfL xRUr64svXpyfJMScIQtBAm0ihWPltXkyITA92ngCmPdHa6M1hMh4RDX+Jf1fiWubzp1voAg0 JBrdmNZSQDz0iKmSrx8xkoXYfA3bgtFN8WJH2xgFL28XnqY4M6dLhJwV3z08tPSRqYFm4NMP dRsn0/7oymhneL8RthIvjDDQ5ktUjMe8LtHr70OZE/TT88qvEdhiIVUogHdo4qBrk41+gGQh b906Dudw5YhTJFU3nC6bbF2nrLlB4C/XSiH76ZvqzV0Z/cAMBo5NF/w= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/28/25 16:36, Keith Busch wrote: > On Fri, Feb 28, 2025 at 07:29:45AM -0800, Sean Christopherson wrote: >> On Fri, Feb 28, 2025, Keith Busch wrote: >>> On Fri, Feb 28, 2025 at 06:32:47AM -0800, Sean Christopherson wrote: >>>>> @@ -35,10 +35,12 @@ static inline int call_once(struct once *once, int (*cb)(struct once *)) >>>>> return 0; >>>>> >>>>> guard(mutex)(&once->lock); >>>>> - WARN_ON(atomic_read(&once->state) == ONCE_RUNNING); >>>>> - if (atomic_read(&once->state) != ONCE_NOT_STARTED) >>>>> + if (WARN_ON(atomic_read(&once->state) == ONCE_RUNNING)) >>>>> return -EINVAL; >>>>> >>>>> + if (atomic_read(&once->state) == ONCE_COMPLETED) >>>>> + return 0; >>>>> + >>>>> atomic_set(&once->state, ONCE_RUNNING); >>>>> r = cb(once); >>>>> if (r) >>> >>> Possible suggestion since it seems odd to do an atomic_read twice on the >>> same value. >> >> Yeah, good call. At the risk of getting too cute, how about this? > > Sure, that also looks good to me. Just to overthink it a bit more, I'm changing "if (r)" to "if (r < 0)". Not because it's particularly useful to return a meaningful nonzero value on the first initialization, but more because 0+ for success and -errno for failure is a more common. Queued with this change, thanks. (Keith, I haven't forgotten about AVX by the way). Paolo