From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 780FBC282EC for ; Mon, 10 Mar 2025 14:46:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D3B27280004; Mon, 10 Mar 2025 10:46:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CC0E6280001; Mon, 10 Mar 2025 10:46:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B3CA7280004; Mon, 10 Mar 2025 10:46:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 9063C280001 for ; Mon, 10 Mar 2025 10:46:39 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id CDC9F81156 for ; Mon, 10 Mar 2025 14:46:40 +0000 (UTC) X-FDA: 83205917760.04.C68B891 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf14.hostedemail.com (Postfix) with ESMTP id 28941100019 for ; Mon, 10 Mar 2025 14:46:37 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=etB0YbRV; spf=pass (imf14.hostedemail.com: domain of gmonaco@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=gmonaco@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1741617998; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=7NBn6thYETvxD4JzG7wm+CZqqHUZNZ9s0pu5TPouYvM=; b=JZMxlpfoP+2icB2C61MgeubaErWS11a/BKt9m3lqEzzb8krm+H2BOrV4OhK66ZfRXxpZ62 LVOLHH0JazVmK1FWrDSzy1HgRCpKQ10fV/jXdX0ZKPBHE8U+MFG3LE4wA3EC/w+ISbqE1h +QDbhA47XInKIN03bzomWsg7MpdoIYo= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1741617998; a=rsa-sha256; cv=none; b=NRcdphPDFs//3jE7czJywIJaFCsI3h9NjHyXE6mDIdeYKiE8S/KiDRCEMmfYZSjqnyQsn0 79DTkMVaMGdPWuexUcamsLpZHEFI29wyIaTwnWHP1NQ+/NVgrAjIAoHvv3/1hEZTeEOvcv eB/NZH9lCdCf+FBlRIlhbfi/AknBWO0= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=etB0YbRV; spf=pass (imf14.hostedemail.com: domain of gmonaco@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=gmonaco@redhat.com; dmarc=pass (policy=none) header.from=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741617996; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=7NBn6thYETvxD4JzG7wm+CZqqHUZNZ9s0pu5TPouYvM=; b=etB0YbRVMQ4XYi2GZdTtgmkA+bJMKpFctgRroPQGCE/E/xseK6wsouRTE7Uwd3Y2P68Gxx DoC17qCnUQ/GdVTEbpCmRH1/v06tZSfksdTTKj4N3HAIVlG/2jxOqZ5SyiNHIACAIwSGnP TNIArnU1L6I84wpQA3W+yXZUTLgvoFY= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-14-HRY5rIfrN6KculcAoNPgeg-1; Mon, 10 Mar 2025 10:46:35 -0400 X-MC-Unique: HRY5rIfrN6KculcAoNPgeg-1 X-Mimecast-MFC-AGG-ID: HRY5rIfrN6KculcAoNPgeg_1741617993 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-43cf446681cso6084225e9.1 for ; Mon, 10 Mar 2025 07:46:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1741617993; x=1742222793; h=mime-version:user-agent:content-transfer-encoding:autocrypt :references:in-reply-to:date:cc:to:from:subject:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7NBn6thYETvxD4JzG7wm+CZqqHUZNZ9s0pu5TPouYvM=; b=CDHWyTWZ9JedarRuC2JK3hLmqfiV2Rj+p/E0j1PFaITRFvJNTPMT3WIdrYp4gg5HdH fcjLtruYXcqFJ2qMGUyr+hQWQ5fvd6VB/kuwu958QYxpFLpwiCJJU/mvAWWQXw6CjWtj OiVQ+2SIP6qNHzjHSPrkW2M8T1vkh/HOsazZZY8vzYaZULDm0gglfrU5orq2bUSsq3r3 L1pBS+WVrmESl+FWukTEmI0KY1uY5kVVSILcXfr13EdaLlbtBaT3yXVN/GlK4f/sRCB+ SC7lUXcMzMzbzifho9PqW0IhWxED54XDjas+6FeGSQ5Evc7X4vcFskfQ3jtQlfA/J8/y u1Wg== X-Forwarded-Encrypted: i=1; AJvYcCUajl/e0wiyV1YIkvbFdzu0wVuhKY5GVAn7E+hIqFAWMH5QTqChCsqgmONEmpyRQkqkJACrxTnpXw==@kvack.org X-Gm-Message-State: AOJu0YwyMLnOEyPoWoPpPEZyQ9Ljfz/5jI2A39rwubFacYVJhKLjSR4v 8WW0eGhw3QOb58VMM/4LYjwvU9PXNDxI0Ta+RuHGNDt2kJCzaH50oaq9e7BGYpMOxXMd1BqXGls pCj0WJPTOizLMtbZU5xqG5YdsnjTnGT4P6jsUplUiMwZwqo7N X-Gm-Gg: ASbGncuPz+cQ7BT1kdQSjqD2/l3NLSdayV8nbVclmeoan9XnhPIoPOkUT7iL8qXFRWa eh/mUGvtgaVZuanDBtj+R/iUR84hng+dm+se/I51ZIWpnSwN1vb8dcqILiwNfMHpmAt71tQ0e3i rWzFYlKZjL8mUpP9Bow9UHPiYaCrWF5KZkuel2u1MSmIvnbagRSS0v37KrtUgtKPYo/Ob5DD9Ls Cn7iA3P/TSsJzMp9pg9kKU8z/jrzd0pkN/MArb58sRekEYZ/F9/wgKUdUujGcqCbloN4R69jp85 07fba67Xy3cchm3xHeoIyJ84SLz9o8A2K/XbGEQQFg== X-Received: by 2002:a05:600c:3512:b0:43d:ed:acd5 with SMTP id 5b1f17b1804b1-43d00edb082mr7759685e9.10.1741617993316; Mon, 10 Mar 2025 07:46:33 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGANFZABLGGy46eqy2gRJs9BwAJSC3qvlHZaJ0LiP+U9nBEsSDR/rVW+yl7lBsadPvWtmflfA== X-Received: by 2002:a05:600c:3512:b0:43d:ed:acd5 with SMTP id 5b1f17b1804b1-43d00edb082mr7759095e9.10.1741617992856; Mon, 10 Mar 2025 07:46:32 -0700 (PDT) Received: from gmonaco-thinkpadt14gen3.rmtit.csb ([185.107.56.42]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-43ceba8d727sm77640315e9.25.2025.03.10.07.46.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Mar 2025 07:46:32 -0700 (PDT) Message-ID: <1c161066bcbc916ae9d97e7d1753ee12511da085.camel@redhat.com> Subject: Re: [PATCH v11 2/3] sched: Move task_mm_cid_work to mm work_struct From: Gabriele Monaco To: Mathieu Desnoyers Cc: Ingo Molnar , Shuah Khan , linux-kernel@vger.kernel.org, Andrew Morton , Ingo Molnar , Peter Zijlstra , "Paul E. McKenney" , linux-mm@kvack.org Date: Mon, 10 Mar 2025 15:46:30 +0100 In-Reply-To: <20250227153329.672079-3-gmonaco@redhat.com> References: <20250227153329.672079-1-gmonaco@redhat.com> <20250227153329.672079-3-gmonaco@redhat.com> Autocrypt: addr=gmonaco@redhat.com; prefer-encrypt=mutual; keydata=mDMEZuK5YxYJKwYBBAHaRw8BAQdAmJ3dM9Sz6/Hodu33Qrf8QH2bNeNbOikqYtxWFLVm0 1a0JEdhYnJpZWxlIE1vbmFjbyA8Z21vbmFjb0ByZWRoYXQuY29tPoiZBBMWCgBBFiEEysoR+AuB3R Zwp6j270psSVh4TfIFAmbiuWMCGwMFCQWjmoAFCwkIBwICIgIGFQoJCAsCBBYCAwECHgcCF4AACgk Q70psSVh4TfJzZgD/TXjnqCyqaZH/Y2w+YVbvm93WX2eqBqiVZ6VEjTuGNs8A/iPrKbzdWC7AicnK xyhmqeUWOzFx5P43S1E1dhsrLWgP User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: -sd-9UIY21-kEv1QRR4TGudApDo-EMbUtv5Dg6Q1MTY_1741617993 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Queue-Id: 28941100019 X-Stat-Signature: kqrf8ipojfdqim6ua58a7ho56goohh73 X-Rspamd-Server: rspam10 X-HE-Tag: 1741617997-183507 X-HE-Meta: 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 rdl0jVR0 moi0dmkiiT42V8wsrkXzK8L2ylm/vSKO/hY7v2Xdt5056ULVqBcPl4sh9NBXU0SEqCaK64qmNFXMdFm4G4ifWzwGsXtVyvWrewhVLNfYHt//UdFkB7YzYCiQfTly7KBCe3m64vNvgbK3kfgGba2OAZUK7xJNlzwL06VqBWhEPySMYGsE6624ZkhbQNJJ7iNZGHRVEM+C6AgV7mjpNoj0tNOMHcU6MLGkOFCf1Q1pewM90jjtRBVHcD/3T/NUDZiMcSYEf35iyevqgiYvQFyUT9fbtSHDGcIbd5SNYDEBjc5yKUTG5xlEBpoTUAYwCwbYYynu1OaRqdDFwYLdK430b9tQ30LZtTNqwQlthvVj9BmPKL5PRFruQRzNXOlA7/APovSI8xLrfEZeasgz58zCbd9ZaMowt/pqCmfCT X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, 2025-02-27 at 16:33 +0100, Gabriele Monaco wrote: > Currently, the task_mm_cid_work function is called in a task work > triggered by a scheduler tick to frequently compact the mm_cids of > each > process. This can delay the execution of the corresponding thread for > the entire duration of the function, negatively affecting the > response > in case of real time tasks. In practice, we observe task_mm_cid_work > increasing the latency of 30-35us on a 128 cores system, this order > of > magnitude is meaningful under PREEMPT_RT. >=20 > Run the task_mm_cid_work in a new work_struct connected to the > mm_struct rather than in the task context before returning to > userspace. >=20 > This work_struct is initialised with the mm and disabled before > freeing > it. The queuing of the work happens while returning to userspace in > __rseq_handle_notify_resume, maintaining the checks to avoid running > more frequently than MM_CID_SCAN_DELAY. > To make sure this happens predictably also on long running tasks, we > trigger a call to __rseq_handle_notify_resume also from the scheduler > tick if the runtime exceeded a 100ms threshold. > [...] >=20 > Fixes: 223baf9d17f2 ("sched: Fix performance regression introduced by > mm_cid") > Signed-off-by: Gabriele Monaco Is this patch missing anything? I refactored a bit to have it build in configurations without RSEQ and/or MM_CID (which was failing v10) Thanks, Gabriele