From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f178.google.com (mail-pl1-f178.google.com [209.85.214.178]) (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 0EFCF15B57B for ; Mon, 5 Aug 2024 18:03:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722881005; cv=none; b=Bx4RPKJ7YRB1ewUFWn7dZwVTuFj3FD+ZosGWRNHP6v95y/7oTDi2xB1eW2rDoIqyPo04GO3TxgHzOY+xMIALbTy1rwzPG8YW/KjIHibceclePl9AtprQZ9ZVXoVBzvJSoBKtrqIORcNvyKUce/PhVORjyhluFSae7DFPmn7p4gY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722881005; c=relaxed/simple; bh=as51Z7m3gx/5gWcwca8krmrjoM5BFfF8FsRSCWuV97M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Z0pM86XzteX2gJhDWDVrwVYyDCO8DnjIRET1J4FQ1pYFj7NcPgQSldYbUWLnZm755pmpO7qHEJaF88DhndfDR+ieAE0hN+JATBEDVKYrHIZ1m0KARlQ1MDNQEyUXli5d/694TpUMRJ4YTuF8YShuH1A+9c5GrIclE5ltEuQRiRM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Bvs6ptHA; arc=none smtp.client-ip=209.85.214.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Bvs6ptHA" Received: by mail-pl1-f178.google.com with SMTP id d9443c01a7336-1ff67158052so18809965ad.0 for ; Mon, 05 Aug 2024 11:03:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1722881003; x=1723485803; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=8zAWVk7ehim7FJEzwr2kwsxKiBLej/6k06J291bcYEM=; b=Bvs6ptHAGTQErvi0l9BttcaPgmGfXlxOB460f3mDYzZ8RMp7FHMST6oCUrsRRQCwtR viyCLuFtnIsdbuRinW+ofTFg0i0hU1XOZ/vLjzPQMRh7+aqDASSWCQmbDtEAHD+B1npY DdZsMPLnNiyhZvUWCDMCLuZcvELuQohZZmVYjfcKRrRkNiXOktQjU2P0rhttTIb4tHsC amA302+2MZhCrKxCapPiHFfIwKtEogczzaHxbyJ/yS0bXK/qYm+yK249//kVidunPsrV 2ZYFzQmfPyOOZHoZN9WeTKkPifYLiN1H8N86rxa5uCP+wjFVkU06D7T39imr9k2nbdff ltsw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722881003; x=1723485803; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=8zAWVk7ehim7FJEzwr2kwsxKiBLej/6k06J291bcYEM=; b=MnQoxYqqGwgv8ug5ov3SZp5vPNem4Ut8EeGgNHwaI6bO/Gght7hmB//Kh7yetXztfq mW30PEFFfA7W0aG0C7vKYXGhzibUj9JPeUzwCgNrs4d4tcqOPjHETIWtwkbbqnRJjasI TIgG53xBbIdhV96pJmgSxKxL9XhWwEdHsu3DiaAWJLWiwkqKEPnNZosJU2JVM8S/snD6 +P+DxhonLypkfS4uGTbvSXQBjkZx/JIURVt+G/sMkdfLZmrNLmX6cS5mM/LFb+u7OCKT tV1QFyYnoi7qwxyvOgOedrisCCyP5dwLUQO+pAgxUTFHCAnD4HTfDbRZddT3AWk1S+Da WgAw== X-Forwarded-Encrypted: i=1; AJvYcCX47e2Uz9G6NQjvTZsi3vBcsriBO68H/QB8AHgtdT4IIhJnU7NLCpQBGZVm5FKewsEZHrRSDpUXyysrxzSB1oS7umMgHfYtbPT0Pc3E X-Gm-Message-State: AOJu0YydmtqIPI/w+6c8U1br0RwOka69aM4o8l2cpEriMCICGpSpIqzQ aN96dxWTkSQNCJbDKpa1gp2tIbJMJ0+Y3UfYoc5b8ZPIurU8ZEA9 X-Google-Smtp-Source: AGHT+IFLBwZbjUTK2Fl4o25aXYGQ6j0cGhTnPexgTkw02M2trZp+D2C+PljbUYND4usWr44tMvsrGQ== X-Received: by 2002:a17:903:24d:b0:1fb:5e2c:986c with SMTP id d9443c01a7336-1ff573bb797mr112127225ad.45.1722881003156; Mon, 05 Aug 2024 11:03:23 -0700 (PDT) Received: from localhost (dhcp-72-235-129-167.hawaiiantel.net. [72.235.129.167]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1ff592aee71sm71026145ad.279.2024.08.05.11.03.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Aug 2024 11:03:22 -0700 (PDT) Sender: Tejun Heo Date: Mon, 5 Aug 2024 08:03:21 -1000 From: Tejun Heo To: K Prateek Nayak Cc: Peter Zijlstra , Ingo Molnar , linux-kernel@vger.kernel.org, kernel-team@meta.com, David Vernet Subject: Re: [PATCH tip/sched/core] sched/fair: Make balance_fair() test sched_fair_runnable() instead of rq->nr_running Message-ID: References: <0b8d4584-6ca2-f810-16fb-e989a0723bdc@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0b8d4584-6ca2-f810-16fb-e989a0723bdc@amd.com> Hello, On Mon, Aug 05, 2024 at 08:51:05AM +0530, K Prateek Nayak wrote: ... > When does this happen exactly? throttle_cfs_rq() calls sub_nr_running() > negating the "h_nr_running" of the throttled entity from the > rq->nr_running. Even deadline entities on being throttled dequeue the > entity (or don't enqueue them at all in enqueue_dl_entity()) and would > have the correct "rq->nr_running". Could you please highlight the path > that might hit this scenario? I just missed the sub_nr_running() call. No wonder I couldn't see behavior difference. I'll redo the patch description. Thanks. -- tejun