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 35596432BDA for ; Mon, 6 Jul 2026 16:37:55 +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=1783355876; cv=none; b=HvV7gxZSIaTf8/5ggTCE4AwV1tsix3aU6fWfZLtmafFrk5inl708DjODu0k9uiCi79R7wjCn7tEibFJqMmySx5c//5HBafjU427FGuAuPvX3pUt6nNwBRRc8kq0jNJfAnlIPdc3A2Z1sWLPLmPW9TxSxD+ah+AadDXHffPFbiBI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783355876; c=relaxed/simple; bh=jWBYVDypr9CPBWk43W8I2bopf/bXzcHLaIRybxKPtjQ=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=WpXN6K8CajkMM8P2TAjFMpjFfSZWhqKx/DfSX0FSkLjQInzbsbN2yG0qhitg2A9WmwG2zJ5zwB/D2FOWuCrx0We5R5OB8F0neAnLkl8c/GlqUMwJ/CSR3SNFFrcGlolSvIm4oZ1MbMLiXDaX2wwBtax++dtjWhu+zlfWo0Kci3E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Xs3Fzuvj; 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="Xs3Fzuvj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C8311F000E9; Mon, 6 Jul 2026 16:37:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783355875; bh=K7WWLLfhsJUYHWgOPRIpL/b3wvmhALqnMZPyNlUP18U=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Xs3FzuvjtXeKBxz6AKycfwSrwXqdcgZlNi+hxDeimNlHi25w10iKNN6ez65JMwI47 3Hlpw8xbbLPxgAJp4gu5aerfPbbIppN65J22cfEvY3OZCJWeulFxBYKCR4jnz++zqE jUn2sVeC1sFAX4+Ad6Ge7ItGqy3Vf9k7m5NBxjQMB8OHyUtsg5IOeKQdF8iK1UViHq TIBPUs9M64VIJjdmmaNX4kaAFDImD+hTBJcuAW4atCM8cFSPxzJT1kN7Ly6jviBlRT P4jRzwjNHGSb4Q095+QLScbe8cvESHShDs7tqBMJu0L5I7VF1rGlNoD2KvQqqwa7An 190SlM5v2Zbzw== From: sashiko-bot@kernel.org Subject: Re: [PATCH 2/2] selftests/sched_ext: Verify nohz_full tick behavior Reply-To: sashiko-reviews@lists.linux.dev To: "Andrea Righi" Cc: sched-ext@lists.linux.dev In-Reply-To: <20260706162819.650155-3-arighi@nvidia.com> References: <20260706162819.650155-1-arighi@nvidia.com> <20260706162819.650155-3-arighi@nvidia.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 06 Jul 2026 16:37:53 +0000 Message-Id: <20260706163754.3C8311F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: sched-ext@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Medium] Worker processes will spin indefinitely if the test terminates a= bnormally. -- commit 5f5f7d1cf8a2f7b2edb91658dc637840224ea1dd Author: Andrea Righi selftests/sched_ext: Verify nohz_full tick behavior This commit adds a regression test to validate proper nohz_full behavior in sched_ext. It verifies that a finite-slice EXT task restarts the periodic scheduler tick when it follows an infinite-slice task on a NOHZ_FULL CPU. > diff --git a/tools/testing/selftests/sched_ext/nohz_tick.c b/tools/testin= g/selftests/sched_ext/nohz_tick.c > new file mode 100644 > --- /dev/null > +++ b/tools/testing/selftests/sched_ext/nohz_tick.c [ ... ] > +static pid_t start_worker(int cpu) > +{ > + struct sched_param param =3D {}; > + cpu_set_t mask; > + pid_t pid; > + > + pid =3D fork(); > + if (pid !=3D 0) > + return pid; > + > + /* > + * Become EXT before touching the target so it stays idle until wakeup. > + */ > + if (sched_setscheduler(0, SCHED_EXT, ¶m)) > + _exit(1); > + > + CPU_ZERO(&mask); > + CPU_SET(cpu, &mask); > + if (sched_setaffinity(0, sizeof(mask), &mask)) > + _exit(1); > + > + for (;;) > + asm volatile("" ::: "memory"); [Severity: Medium] If the test runner terminates abnormally before reaching stop_worker(), will this orphaned child process continue to spin indefinitely? Since the child runs under the SCHED_EXT policy and is pinned to a specific CPU, an orphaned child would consume 100% of that CPU indefinitely and potentially interfere with subsequent tests. Would it be safer to use prctl(PR_SET_PDEATHSIG, SIGKILL) after forking so the worker is automatically killed if the parent test process exits unexpectedly? [ ... ] --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260706162819.6501= 55-1-arighi@nvidia.com?part=3D2