From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f201.google.com (mail-qt1-f201.google.com [209.85.160.201]) (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 ADD9C265625 for ; Fri, 14 Feb 2025 13:59:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739541556; cv=none; b=c/ekXMDEMJ7slTs9ft2ln3N+HDuoJAd+AuoURBzhzV9lBE9ydRgVwgzI0Y/1TTMT4CV5obc1T0jBio4JrdeKotDQOyRbWCvCsixqeoapzbjGxAiHzCs/iG23tDA9CSx5P8bLad56nMjXfpqYAU/1v2Ap1SS8cGE9D3kuyruaBKc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739541556; c=relaxed/simple; bh=c4hwPm5I+iGag5k57vo9RtkUDn2qEco9aG2ZzSyswBk=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=OppaEQ19SK0c43l5+TpjCJC8/X5yxEeUG1sVktluJgjxfjM3o0iKZmZ8EsEsOJsK1GypG3mIxYn3iTtvJwbw3frod/i1hulbwBn9KMDNg/yYA/mpY4EHubjRmmSvNaOHYVAbNSYigR99o6qPxmxfbZZgI7MoxbwDEWDX9Sy/4u4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=iKdponA8; arc=none smtp.client-ip=209.85.160.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="iKdponA8" Received: by mail-qt1-f201.google.com with SMTP id d75a77b69052e-471c9a003d7so27121211cf.3 for ; Fri, 14 Feb 2025 05:59:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1739541553; x=1740146353; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=FsJUg6tFTkRM0/Q5BqHPBoWfjSFSVcg/i86iZPbawaw=; b=iKdponA8T3jNkFW6XIzLV/XVS76a6lHLa6qCynLcfxZlgZU856O8uwGdEdWVz6gm12 aockpmXrMYaZad86pXh+9X6E42PQfP5DnsnR3RtORaC92kmODNzHB1BvHpFOktJWQ0Sw t3XqNTwakxmKp7lXaJTsEf5qZMvUm4nmU+zKvaSlGtvUmAhjypzMmYJ7gSJzlrVx4hFE kWKJ5uqZ1jyaunc62r1MWJ5vdi9YPE/CbmUC7Uswlfd5cfi/ov0QGcKiQvhCYKF4hcyq WF0DW2Bl4LOduWgZqDRjDz3MaQ1uZ0HLEUm5zhd56xIsBrb1y/CMPDA2c2fe3COF0mau vtdQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739541553; x=1740146353; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=FsJUg6tFTkRM0/Q5BqHPBoWfjSFSVcg/i86iZPbawaw=; b=jNPhxHH8ACvVjNBK28AYGcY6LkHtD1cOocmpxBGafQM8wzgWj5UOwXqC5E07aA1Rew E6rEf6OgIB7FaNSkVdLqxvoquTLu8mSjDfpIX31pZ1/gl7Bd0VQOX81j0/Wm0IZSuAbJ Z2ukP7LXgs02JCTTRfWcIaydiOGZgQ+aDGc62jVqvE4d1YNt73AezEQMQBkRLDEIDOFR U3yQt6T59pCek8Q/p5SEF7alQyWCKHj8sSHnU26rUjYSy1rbxSYq0J2cByRLWa4jIo4w les+ToXc6G80nPcOqBYPhMeCaQDCWuIh69iNv11vM/Icb56hpVw4c5crK1IZN/jjEsXr 0yNw== X-Gm-Message-State: AOJu0YxoisyUWYCp2ty6+ZoxZ4qrzVW8n6zPx4vLsouwgr/sWyEK5W0b tKp2afNOcUcZuxrrHl4I77otogS+fUpbXsXmwtGGxVLCtI/Xp2ybSFCr6n7Jy/iRlGkOxToIEuW 3CEFEQzm1Ag== X-Google-Smtp-Source: AGHT+IF0SW9cv4wdhw79cskfWrvEh1gegUQWimZPIDU2g9CBcGCoTv+56o1d7VmX0BwaFYzA2dL3onZo0FFcmA== X-Received: from qtyf15.prod.google.com ([2002:a05:622a:114f:b0:471:c812:f7f]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:622a:242:b0:467:5ea8:83df with SMTP id d75a77b69052e-471b063f751mr168149501cf.30.1739541553575; Fri, 14 Feb 2025 05:59:13 -0800 (PST) Date: Fri, 14 Feb 2025 13:59:09 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.48.1.601.g30ceb7b040-goog Message-ID: <20250214135911.2037402-1-edumazet@google.com> Subject: [PATCH 0/2] posix-timers: Reduce spinlock contention From: Eric Dumazet To: Anna-Maria Behnsen , Frederic Weisbecker , Thomas Gleixner Cc: linux-kernel , Benjamin Segall , Eric Dumazet , Eric Dumazet Content-Type: text/plain; charset="UTF-8" We had incidents involving gazillions of concurrent posix timers. Benjamin Segall is planning to add a cond_resched() in exit_itimers() In this small series, I am reducing hash_lock contention in posix_timer_add() Eric Dumazet (2): posix-timers: Make next_posix_timer_id an atomic_t posix-timers: Use RCU in posix_timer_add() include/linux/sched/signal.h | 2 +- kernel/time/posix-timers.c | 21 +++++++++++++++++---- 2 files changed, 18 insertions(+), 5 deletions(-) -- 2.48.1.601.g30ceb7b040-goog