From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 6AF1F3ACF1E for ; Wed, 25 Feb 2026 12:24:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772022292; cv=none; b=qDrzxVycPO6NN1zZEfC+qAG+OoXEXAOwmlLMBR5jI0hlr+PgOMRsJ9AmP04i4IImlif1EyGdP486cHDgoKoM7Ay5gNb6vvjcGat8CoZMX/+WvncNQbaqGguR48UV0VSPnSUU95E3CeUWoH64o+oywAZmzV4A9kUhB5omKjQyZic= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772022292; c=relaxed/simple; bh=U257YdxdwDD5/SgQz18TMn2ak9cgpijlpsO3hFbhA88=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OPrZd9+d/Q6f+k24PK6Zresalls/d0UCIMrCdm55eFadhakM92pslgunDG67fcpt9X8qCYEvlGCmOxFXlav9kkWOioWmbpI3CycWVIgKq7vTrne27307EEvURJttVfy5siKiF+zJ5+7hBOMPm6BLcDphlCj3I48gSrNTv7A3i2w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=RkSZ4nu9; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RkSZ4nu9" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772022290; 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: in-reply-to:in-reply-to:references:references; bh=U257YdxdwDD5/SgQz18TMn2ak9cgpijlpsO3hFbhA88=; b=RkSZ4nu9iwjUGhjIyUmTT40jC31FVaUEPNewDyTjv1jh/JWHC+XO8mFbjU29tvGqkkFIch nUTd4g9297mFAEIIqA9ipx51/8yXHAVCZCSJYi36Zh/uiuTiGEn4ilVOGkhEYDodt6+xrn 4tNniQ+Bpb/3kmEsK9MWy13lCZ3Gc+U= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-522-N0jqdGwYP0SRQhDomDtz2A-1; Wed, 25 Feb 2026 07:24:46 -0500 X-MC-Unique: N0jqdGwYP0SRQhDomDtz2A-1 X-Mimecast-MFC-AGG-ID: N0jqdGwYP0SRQhDomDtz2A_1772022284 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8D83A1800464; Wed, 25 Feb 2026 12:24:43 +0000 (UTC) Received: from fedora (unknown [10.44.32.38]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 2B60319560A2; Wed, 25 Feb 2026 12:24:35 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 25 Feb 2026 13:24:43 +0100 (CET) Date: Wed, 25 Feb 2026 13:24:34 +0100 From: Oleg Nesterov To: Pavel Tikhomirov Cc: Christian Brauner , Shuah Khan , Kees Cook , Andrew Morton , David Hildenbrand , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Jan Kara , Aleksa Sarai , Andrei Vagin , Kirill Tkhai , Alexander Mikhalitsyn , Adrian Reber , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v3 1/4] pid_namespace: avoid optimization of accesses to ->child_reaper Message-ID: References: <20260224164852.306583-1-ptikhomirov@virtuozzo.com> <20260224164852.306583-2-ptikhomirov@virtuozzo.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: <20260224164852.306583-2-ptikhomirov@virtuozzo.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 On 02/24, Pavel Tikhomirov wrote: > > Also let's add ASSERT_EXCLUSIVE_WRITER before write to identify to KCSAN > that we don't expect any concurrent ->child_reaper modifications, and > those must be detected. Not sure this makes a lot of sense in this case, but I won't argue. > Suggested-by: Oleg Nesterov > Signed-off-by: Pavel Tikhomirov Acked-by: Oleg Nesterov