From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f53.google.com (mail-io1-f53.google.com [209.85.166.53]) (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 B8D5D53AA for ; Mon, 29 Jan 2024 20:30:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706560234; cv=none; b=GuGHXS1CuhBpHwgIpaD0Fun1LEIFRKCjoY5DwLrmrj90OlBvrt8nk+tC9Kgx6xLsHXokDQoq6j0D3uUrYaq1EN1YW2O6hkmdTfg3HfanS1loioHRTqPLtnHALgrMlB6c4j8ADMCQM7fmFgDIcGAK3I+xMQnjUfiCQVuQL3TzVhE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706560234; c=relaxed/simple; bh=rtna5W2mngQDMY5fUo1xg7OtRajWoiov2CUKWbT6QYI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=jukPja86roOyLHR9rNrByfSrOpStvl8ykchbVrOpjcYYQj/OYBX4ItfcEVVxZRv7aXTd9kkTWdTOdajMTpb+Xl0GmN5qjtPx9R5FPy6X6r/9DM29KjJxpD9V4NDT+lhphioL9QHJ/Pphl9/gu2BhZjuqH2YKw2dHsbckccvQgIA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=PFCkibL7; arc=none smtp.client-ip=209.85.166.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="PFCkibL7" Received: by mail-io1-f53.google.com with SMTP id ca18e2360f4ac-7beeeb1ba87so49127939f.0 for ; Mon, 29 Jan 2024 12:30:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1706560229; x=1707165029; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=UbwMv5LPvIYdmT3qQloO+hwxsGlCpbQZEopYn0536Ww=; b=PFCkibL7+QjKesCKxxLa15gYnRSRv4cCu4LaiABHlaw1Dn50dds0O5BBgUa9sdCCfT 4NihsmDzqksOfoFzHx3uy3NsP0Z8BIpM6B+iaQMOB9UKVgf44G53L7wrQxOSQ3WciI7l ob0Zv4XlOZNeKDdhFEOTBopARknT7hQJH1uhmVvfvuST2hagSnKwCs7v+K8nEcSTFxkG 9ydu7exQf/vmqo0VFJjkdRVIQPPccZuxRvCV5vkbBZ0qYD1muq87B4krhBpc1k0LVfsQ XBIfGegnxIU9xOOoYXro1K1d1RsC63OUJV+/qNIU6NASDkmQtJwTKKR6fjg3ZXjGguWW m2LA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706560229; x=1707165029; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=UbwMv5LPvIYdmT3qQloO+hwxsGlCpbQZEopYn0536Ww=; b=RqeUvEs43tOFBRud55oBFyJeZSsIme+qMYbAwCsnIpPoT/61chW64iYdMyd1B35FGQ 5uF+WucyG8uoKrrczEa48afaXzGDSyHnfWRhTYDHxYK+6urMrmTgPhot203hrNZejv3b veoHKLpuypjt50lQfKOKUTlegwsXMtCBdfuKec/ELZilHCjInuzxzBaoxfSsM2az9Wf4 8JUhg6agU4mKpuCBbyvsFLVtuoEdqZf+uj0RbdtVR70qHuXahjlzTl/6iKvjHZIsB0nX ebVsv1E/R2T12bXaCe0NY17rYeZZb8/puchqLIQWzgWI98G+s7m0WFgIGbtBNuEHdntE AcZw== X-Gm-Message-State: AOJu0YwoaPNnwoEJJcmTJ/Qa8J41WZ0CAlAZzEDvEbdBsTySVF6xCwCp L7N6LkZoqmQ0NdMIsdWaEJD69qfhS/SFm22VB0NBeZ+B4UK27zULS0p+UXpUk3WJMMAcRHfOfT7 yICU= X-Google-Smtp-Source: AGHT+IHBpunw9VFXBPzKkoTiOy1o3WcIsxxFSqJJSyunPmJYLFxF1EJ1BLN8p2B1lieF+RWJj84SCA== X-Received: by 2002:a6b:f814:0:b0:7bf:4758:2a12 with SMTP id o20-20020a6bf814000000b007bf47582a12mr7197960ioh.0.1706560228818; Mon, 29 Jan 2024 12:30:28 -0800 (PST) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id i8-20020a05663815c800b0046e6a6482d2sm1952510jat.97.2024.01.29.12.30.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Jan 2024 12:30:28 -0800 (PST) From: Jens Axboe To: io-uring@vger.kernel.org Cc: asml.silence@gmail.com Subject: [PATCHSET 0/4] Limit multishot receive retries Date: Mon, 29 Jan 2024 13:23:43 -0700 Message-ID: <20240129203025.3214152-1-axboe@kernel.dk> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi, If we have multiple receive multishots pending and one/several/all of the clients are flooding us with traffic, then we can retry each multishot receive many times as we keep having data available. Some quick testing here with 8 clients over a 10gbit link, I saw one client do more than 32K retries. This causes an imbalance in how we serve traffic like that, with the result being that each client will see different throughput. 1-2 are just prep patches, no functional changes. Patch 3 doesn't do anything by itself, but it enables the fix that is in patch 4. That patch limits retries to 32, which should be enough to not cause any extra overhead, while still allowing other clients to be processed fairly. io_uring/io_uring.h | 8 +++++++- io_uring/net.c | 49 ++++++++++++++++++++++++++++++++------------- io_uring/poll.c | 49 ++++++++++++++++++++++++++------------------- 3 files changed, 70 insertions(+), 36 deletions(-) -- Jens Axboe