From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1313E3BD65D for ; Mon, 5 Oct 2026 08:53:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791190403; cv=none; b=PE4PP0PM45cgh0f90BwnnOJAiP9nC8Bcex00+T3p37YXRj8ge+Wjdy4mqLdBkJQgCLej5hcgPtD2FwAYGmMLvWy3Qv6jaetrQSBvC+MeYGr2cV55C/VKSfhuXDdoUhDgVJx4SS8Wa+dvdSL++py1xXIhUirW94+TDIGNNi0xRcM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791190403; c=relaxed/simple; bh=73e0GzCo6tU7Be9TmYg6VzR1qt0Xkf94+tBNd/Q7rAM=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=Sl7ow+Jt+DYMCPKS5lMvde9PwvOdHUprW9Ikk5QHDV6bX/A3f8mxzFHb7Vjry3/c7HWUxymCQ0/quvzaRj75p5HWlt200NiVN8Nyiq0jMreyUiAukDomCeFj16mTHvb3NmOa8bIJRoydGIcwXTH6Ym5boMlOmOdNztAEJCMsTHM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lV5Spktu; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lV5Spktu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6E5C1F000FF; Mon, 5 Oct 2026 08:53:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791190401; bh=FJP7kEK8LyND5+M8FG3WSfzBgSlxPDbimt7LRGZH+AM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=lV5Spktu0M/XjuPkxxC1Ws81x+Wji4KyoNzf0WOrArFYltCm7CGCaZ0wflyiVVG5g E25P9HOJTbMoiGFLuga2cETk7tEydPZQvspltZwfTuzsG+TcQOhJppWg5FbyfSci5B Yeb6wmiPZ42Ki5R3yvP+gElMxFT0XmdGtnMPY9Jdwk7CMRnMAW0/Hw09qIe20iYOuP wPhKcR92UzUFKk86qWkKYCAROSSx/fINGaQ3Vqeq205vvVYMsm2i7xkkJOu2l2khtn XMS4vt0mYjKRPn/V6ej19Ei8S6i0DoGcWY7tx+QAUHhUTqVvFGEHuzlpvqWAS+97xI X99j0OarP03bw== From: sashiko-bot@kernel.org Subject: Re: [RFC PATCH v4 1/9] mm/damon/paddr: remove page_fault access check primitive Reply-To: sashiko-reviews@lists.linux.dev To: "Ravi Jonnalagadda" Cc: damon@lists.linux.dev In-Reply-To: <20261005-damon-perf-rfc-v3-send-2026-10-03-v4-1-b03452e137f3@gmail.com> References: <20261005-damon-perf-rfc-v3-send-2026-10-03-v4-0-b03452e137f3@gmail.com> <20261005-damon-perf-rfc-v3-send-2026-10-03-v4-1-b03452e137f3@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 05 Oct 2026 08:53:21 +0000 Message-Id: <20261005085321.C6E5C1F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: > The page_fault access check primitive reports faults through > damon_report_page_fault() into the global, mutex-protected > damon_access_reports[] buffer. A later patch in this series replaces that > buffer with per-context rings fed only by perf-event probes, which leaves > the page-fault producer with nowhere to report. Remove the producer here > so no report is silently dropped. >=20 > Remove damon_pa_prepare_access_checks_faults() and its supporting > damon_pa_change_protection()/damon_pa_change_protection_one() helpers, > and the page_fault dispatch in damon_pa_prepare_access_checks(). Remove > damon_report_page_fault() and its sole caller, do_damon_page(), along > with the two page-fault-handler dispatch sites in mm/memory.c that > selected it over the ordinary NUMA-hinting fault path. >=20 > Writing Y to the sysfs page_fault file now returns -EOPNOTSUPP, and core > validation rejects a context with page_fault set, so a configuration > cannot select a primitive that no longer reports and have every region > read as cold. With page_fault gone, page_table is the only access check > primitive left, so a context must enable it. This leaves MM_CP_DAMON > with no user that sets it; its check in mm/mprotect.c is left for a > separate cleanup. >=20 > Signed-off-by: Ravi Jonnalagadda Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261005-damon-perf= -rfc-v3-send-2026-10-03-v4-0-b03452e137f3@gmail.com?part=3D1