From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lj1-f182.google.com (mail-lj1-f182.google.com [209.85.208.182]) (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 BE17D18F2DD for ; Wed, 29 Jan 2025 18:01:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738173721; cv=none; b=nHUsXRxpGy4ahSUkcDoXQSkWtPay8TxI4mFcSX2kjDvnk9Q5/e75RE+dejyG6LFxgRljQv/oBnGilsPcp306KfzrdI6VsB7J+efe/nnAY68t2tF7zrbeKsbjysmbcvsMMOOqL+h56lBNMQYDXF923f3+GC6o/fcgVKoVzy0ffIs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738173721; c=relaxed/simple; bh=Rsv58VeE5zC0QN8PhuG0t9155fC5Mi9wJwqubDybmzs=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=dR41FrZptiU+bY2y+tC8rdHa0smzxiXR7AGoljbAET+G9SQhGzwZg6BfoP5WnDRw4DkXS0RRMKBRscxQE8EbjuRXNmF8En3mI8SVW1VEiRcJ3KUDFBwfVb1ENkLGoNtG5Y9EsYJ/24ZWLzy0WHjoG5Sxqu2GMgVXfGFYx+KTTwU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ionos.com; spf=pass smtp.mailfrom=ionos.com; dkim=pass (2048-bit key) header.d=ionos.com header.i=@ionos.com header.b=D8AC3OMR; arc=none smtp.client-ip=209.85.208.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ionos.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ionos.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ionos.com header.i=@ionos.com header.b="D8AC3OMR" Received: by mail-lj1-f182.google.com with SMTP id 38308e7fff4ca-3076262bfc6so72470601fa.3 for ; Wed, 29 Jan 2025 10:01:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ionos.com; s=google; t=1738173717; x=1738778517; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=Rsv58VeE5zC0QN8PhuG0t9155fC5Mi9wJwqubDybmzs=; b=D8AC3OMR/uz/srALS514fcNN8MpnSHJg0CvPJYF7Kp430dFx0FPpc2Lwk2dOTk0aqO I4aACkc/HzBO+ZE7dVLVQL2OK5Ml4jQwbd7loXxWpZU5XgrE58dltLqp3+s8Z0eyaPVg 7J4Qve59BrR5rpKgWwPGYp8ikUDKkepnOeNsX1SjZGmlDeIX9j1hBB2ubCsJDWTRUmxr aUYRP62sRVSVsmHEa+0GorFuaJ+iTao6KtEcTQOwvf2Es1qFNb+VUg9eCiSXNxQ21hcO MSuwJ3QIbcXYg/xCqiG7e437iar3luFpS2jGRwSVtAlX9z3SECvKEuvGvyIcs5omDiL4 VIEg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738173717; x=1738778517; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Rsv58VeE5zC0QN8PhuG0t9155fC5Mi9wJwqubDybmzs=; b=J8eFw6J98hyX9Hcry3DibsUjzgngQKfdfAh10ClhDqzadbRv02K7BQ8th2hQvp+TbA 0upa6+3O7NGtNsr8YuuYlNl1u81vEnSMZKDlicjkUC4pVl6do/LaXuS8o6B5NmuxnS3z i/F119vwph4Iaq/KpcWabQ3o0QD/0K17pIBP6qFaOxhMQ7vt4wO8uYHNnLO5eaonsCOV Fj9I90qt6u6byGz7PgjbGXCWiVobJufrJ2VtFahj2jn+eT9vxMprOyvigw9H8Mv8pql9 sMrJqtG3HShze3qMERCVt41d3nRL8dQf3KbwZQ9HP6xYb6psOokjUWE5nJDaH6ZQ36mQ 58xw== X-Forwarded-Encrypted: i=1; AJvYcCX7EM9VzVKdiHJJYMiEkmQ3k1GEAOupgvW17w3ajrOgC/rfOej9Fo+p58UTBgrqerqWly7E4WuOYQ==@vger.kernel.org X-Gm-Message-State: AOJu0YyFEsxHArQyhIQvQ+gniUSm43FAUWkWH/W3El43G8XlfvOmamXm IKbxFGF/PoCUS0zRJamXdIa5XSfyGlvLRTTMXpT4XDK9thH/ezb9/p9JvQxiy2gz2ajnKTzJ6yt M2Z8UE/2JffS/g27LNMMp8ws5BcwR4vuTF8k1yQ== X-Gm-Gg: ASbGncsdFT29CWzDUnszLzAEtRPR5bddGTX/byIjjEdxXQ9pE7/W/0zpj0e6CEGMikv h7XDLHc407lzy9ltMS0XE65kBC7mDDdVlU120c2gGaxKrBKoei00QHQusfv8fLZ81chRpwWsX2O 9nlD137qEYiPGDYF6FaQTAMnGPtw== X-Google-Smtp-Source: AGHT+IENHbZtfqKdacz2TNrUOowVMg9fJi5BiMkAVvxHm5n/a4zcb2hRxrG4NlKIk0EXIcJAlM1uqL9ui//0I13OXE4= X-Received: by 2002:a05:651c:1614:b0:2fb:8c9a:fe3f with SMTP id 38308e7fff4ca-307968a41d3mr18570851fa.22.1738173716252; Wed, 29 Jan 2025 10:01:56 -0800 (PST) Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20250128133927.3989681-1-max.kellermann@ionos.com> <7f046e6e-bb9d-4e72-9683-2cdfeabf51bc@kernel.dk> In-Reply-To: From: Max Kellermann Date: Wed, 29 Jan 2025 19:01:45 +0100 X-Gm-Features: AWEUYZn6QW-kL4zyjx3r3G-mpQn_W50dNn--yQd1QkzUZM6D5YIUhotanfkgquk Message-ID: Subject: Re: [PATCH 0/8] Various io_uring micro-optimizations (reducing lock contention) To: Jens Axboe Cc: asml.silence@gmail.com, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, Jan 29, 2025 at 6:45=E2=80=AFPM Jens Axboe wrote: > Why are you combining it with epoll in the first place? It's a lot more > efficient to wait on a/multiple events in io_uring_enter() rather than > go back to a serialize one-event-per-notification by using epoll to wait > on completions on the io_uring side. Yes, I wish I could do that, but that works only if everything is io_uring - all or nothing. Most of the code is built around an epoll-based loop and will not be ported to io_uring so quickly. Maybe what's missing is epoll_wait as io_uring opcode. Then I could wrap it the other way. Or am I supposed to use io_uring poll_add_multishot for that? Max