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 094EB3542F6 for ; Fri, 5 Jun 2026 21:05:35 +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=1780693537; cv=none; b=l5veCGHiq6YFCACmRlzCu8PqGGhV3F4MWTVZjT2Pr488Y/m5uzkr0CYzB3MvpI1lnAqKDw+MYrSUoqfT0NH/Mc+bg2XoUbXEri8UCtMpiGGD5m2BO4+CN483/Vz0PvzQyzR8vThI8HkUIDUIanHLPOPtFn+wTVE5vGa6rxX4oOI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780693537; c=relaxed/simple; bh=mBK5MuzFQwp/2zV1ZfnDQxgcMA87d/wy7qm9TgukkCA=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=cq4Lx/kw6L78fR833rw0ZMBr0CYjbwWGjOOc/5uWiMhVX19GdGY5T7sWDL18tPHnltoTWmmab6ZdkkXhe58iSu5gWRXK10YAdKckLLW1gghWg2a1PlJOBQF+7uYWiOGUHzq0jHaeW1tz2LK//lLukCbDw8dTKaHymgeEyhtMf9M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JW8T4w3L; 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="JW8T4w3L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8AEA51F00893; Fri, 5 Jun 2026 21:05:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780693535; bh=mBK5MuzFQwp/2zV1ZfnDQxgcMA87d/wy7qm9TgukkCA=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=JW8T4w3LGA63E1vOJtI4emBZwr7w8WYuLd0PGCTMLiS7IY7rrch7bNuTpbpIK0ub7 Ud2uf5/gU5MsOcb3qy1g0JWOF3nmgAoSjVEXzzFiqS8/fvN++i5h6szJkAUYzUTaG+ T/KTa9eOV+uwBj5vuZea6g0QjYfGazN8gCN08elP4CJj1SY/rMoiAl2O5xlCbGYG+q Rc68kZtamJJ/frUOTKEnDK6XYMekVCYyolwIYQWck6XpBbBAj+BKHEUXncPlgfh6kA lZiRaOLBIcu/F2uN0AJOdZ4EO+DJCsi1JBbuwIHOUMocNXj5ipZukvJfusbyXIOs4n Q+B92Sp3JoeQw== From: sashiko-bot@kernel.org Subject: Re: [PATCH v14 4/5] perf test: Add inject ASLR test Reply-To: sashiko-reviews@lists.linux.dev To: "Ian Rogers" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20260605205649.2566948-5-irogers@google.com> References: <20260605205649.2566948-5-irogers@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 05 Jun 2026 21:05:35 +0000 Message-Id: <20260605210535.8AEA51F00893@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Medium] The kernel workload for sampling (`dd if=3D/dev/zero of=3D/dev/n= ull bs=3D1M count=3D500`) executes too quickly on modern systems, risking 0= kernel samples and causing flaky test failures. -- commit d9af52a5de1d8869d352d74aa99a8ba4f6d3011b Author: Ian Rogers perf test: Add inject ASLR test This commit adds a new shell test inject_aslr.sh to verify ASLR address remapping. The test validates sample generation and address remapping across basic operations, pipe modes, callchains, and kernel sampling. > diff --git a/tools/perf/tests/shell/inject_aslr.sh b/tools/perf/tests/she= ll/inject_aslr.sh > new file mode 100755 > index 0000000000000..d8ded16ba9052 > --- /dev/null > +++ b/tools/perf/tests/shell/inject_aslr.sh > @@ -0,0 +1,464 @@ > +#!/bin/bash > +# SPDX-License-Identifier: GPL-2.0 > +# perf inject --aslr test > + > +set -e > +set -o pipefail > + > +shelldir=3D$(dirname "$0") > +# shellcheck source=3Dlib/perf_has_symbol.sh > +. "${shelldir}"/lib/perf_has_symbol.sh > + > +sym=3D"noploop" > + > +skip_test_missing_symbol ${sym} > + > +# Create global temp directory > +temp_dir=3D$(mktemp -d /tmp/perf-test-aslr.XXXXXXXXXX) > + > +prog=3D"perf test -w noploop" > +[ "$(uname -m)" =3D "s390x" ] && prog=3D"$prog 3" > +err=3D0 > +kprog=3D"dd if=3D/dev/zero of=3D/dev/null bs=3D1M count=3D500" [Severity: Medium] Will this workload execute too quickly on modern systems? The command transfers 500MB in 1MB chunks, resulting in only 1000 syscalls which could complete in just a few milliseconds. With perf record defaulting to a ~4000Hz sampling rate, a workload completi= ng this fast might generate very few or exactly 0 task-clock:k samples, potentially causing flaky test failures. Could we replace this with a syscall-bound workload, like using the default 512B block size with a larger count, to ensure consistent kernel execution time irrespective of memory bandwidth? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260605205649.2566= 948-1-irogers@google.com?part=3D4