From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f45.google.com (mail-ej1-f45.google.com [209.85.218.45]) (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 8AB2135953 for ; Sat, 1 Feb 2025 15:30:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738423825; cv=none; b=IE5HE7KG4gy1cwiSa9w83hzYCJFa4/r53+s5Fbhnz1pkrP3KIAJgK0J2kBvrkHTviF1GrBLO6KE/8grhTUxpJcYZZGog+5AlaCLRdu/6yxK7EOz3TxkAZF5TaY/pahh7PjNU8zYv0m1UgPPdAwr/JUjwrUh3bqbwDRJbj4+g7xg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738423825; c=relaxed/simple; bh=jLAFeOa4B/Ui1zQ/QRR3Ay8hxmZN3q4aytmcl4FjB88=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=j0104LFADb8yGv/7EDLCRzXDfvk35ASnRhcxnkueYU3uxxPjruBttwUs/0YIpzm+nUGT4SzGT/RFbInsoRUXCX/RnVCH1TTHxxUeTfh1WgS68FHRMYigkYFqwlMx2NXGLWRru3G5pYRuO/JBojRiASzWeWTSloDBaGth7gBFap0= 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=bDdHWCRb; arc=none smtp.client-ip=209.85.218.45 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="bDdHWCRb" Received: by mail-ej1-f45.google.com with SMTP id a640c23a62f3a-ab69bba49e2so440344066b.2 for ; Sat, 01 Feb 2025 07:30:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ionos.com; s=google; t=1738423821; x=1739028621; 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=jLAFeOa4B/Ui1zQ/QRR3Ay8hxmZN3q4aytmcl4FjB88=; b=bDdHWCRbrJTQHW/t6UBBd+9h89pXdjWvq0qaFJpE6ZI+9VV8kzyTwV6opPwZ5iJHg7 wnUz9k20njSnj06DSRkKp3JqSjkk3jByiBzMRYSIEUwx9ZW1rNem0XVRzNQPyYwDpEEC 8RYmHIeaLxSyPkndEO48GQXJ1Bew6Q3pjXanufYccN5QvVDDfVGK38HWzUx8kXDvZ+m/ ZfTIgPM30npnz3AA3oVa07Uui9I9Gl63/UptwuM5URNm32WLySsGAMk8cQJZcI2APoiB eRewXUDm/P/LBhdSPbxHuHesOSBzCettrNMCmxBMhF2V3wx4olZ1yik6Q+KQlj87R6Hs xLAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738423821; x=1739028621; 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=jLAFeOa4B/Ui1zQ/QRR3Ay8hxmZN3q4aytmcl4FjB88=; b=hV83/zbGRY5BXm8LIvov/gGnAc8jMHMTTEMf8Up5Tx6Hl8j7Me3a3i0d/cFKxAs4jp 1so3e+fmkjgPIPXBQlCY+I1DwCjg+WrizrcEiLHCYApz771JFcHWbVPVYXdxsnPz4H6K WvRg28415SgDUHzssL8nHKNY3hwzzcThejlSiOFDxZJxOv/l8L+b+doRBPdEWwX5CPRP e4CQQCR8+pok8WuOFNpbciLml5j9bz49xqvgQySprbNOzkcHlYD7kE5sHuRYpQwhKlc7 xTHqYjoMBe/3wyFEAkOiS97MESTEvnToU0pdXwYRczn13aMlFW1HAkyt44KfclFXakCY WZXQ== X-Forwarded-Encrypted: i=1; AJvYcCUvIHXn7av0fIGTJiNGCoKwKc0gY1KTVijpeHhA8944drTZUtAS/QCaXpb+TTJS4PA3IaSLzSjbkw==@vger.kernel.org X-Gm-Message-State: AOJu0YwYFrBklRc1/hr2nVBznat0WrjC7hA1DG5qihl+dU3iNGJF0kOP QE050AkI6tNlaNNdMvypjhMhEkfYVQTtpywTYGmAHn/AZZ2ea30wOzmCmFB3e8skcBZPyHwOk/2 r9op+exRyoR8+ZXdGOGD73+F32UFacrM+esoeMA== X-Gm-Gg: ASbGncuG9jxedPtZ+T2OmJz7iPQyLdaDRnfM03L+srCdeXvq21NAd7nSnOpBisU1T96 hFbxj+0PEexEth/3T6O565AYqu0flbQEM/s/01cHTKDiFURb+vBdDmWO2mXpRyw9JQyLJ2PMOgC r4y8s6/2b9Pj+xeKvnUt0/Wisazw== X-Google-Smtp-Source: AGHT+IFFfVIGpqQJoDACtjvcQRkIcsgXRPVYG0JR7kLuxe3GgL7axL6RzBLZ9L8GIQHNcLs2mhYll9C7B+CqrxPawts= X-Received: by 2002:a05:6402:5205:b0:5d9:ae5:8318 with SMTP id 4fb4d7f45d1cf-5dc5efec050mr35634701a12.20.1738423820832; Sat, 01 Feb 2025 07:30:20 -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: Sat, 1 Feb 2025 16:30:09 +0100 X-Gm-Features: AWEUYZmz9mAYxPgfq5lQNW0GlIwU_G0PYShDHmlvC05ISUvP8Ww8dmTy8WqAP3Q 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 Sat, Feb 1, 2025 at 4:26=E2=80=AFPM Jens Axboe wrote: > > Not a huge fan of adding more epoll logic to io_uring, but you are righ= t > > this case may indeed make sense as it allows you to integrate better > > that way in existing event loops. I'll take a look. > > Here's a series doing that: > > https://git.kernel.dk/cgit/linux/log/?h=3Dio_uring-epoll-wait > > Could actually work pretty well - the last patch adds multishot support > as well, which means we can avoid the write lock dance for repeated > triggers of this epoll event. That should actually end up being more > efficient than regular epoll_wait(2). Nice, thanks Jens! I will integrate this in our I/O event loop and test it next week. This will eliminate the io_uring poll wakeup overhead completely.