From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 C42612E3394 for ; Wed, 2 Apr 2025 11:23:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743593038; cv=none; b=MCgg4kRvh1DlfXDBlVa8HmG1F5UhijhIj1x7Hfwr2HGsu+hrNaV7wCB4tdmW0ahJlNL1sgf5V04g6vJRzNw7aTCVN97hRLNAGG1TfwkoJ8U2nB30/vw09Y+hN1VRYO+DTZe9oPmx+jNKgajlGYGWlTL7Lx1cRBvtnyPqHj9N8XQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743593038; c=relaxed/simple; bh=/KWPVDjJCugQVxRyMdQMO4pqMQ/vWo7Ji66wG+/Klyw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rcdYu6qVvTjgCYBhnag+YfB9QBX7oGQDBZcrvylmsLufrf8d7Mo4D476o6SFEtoZ26ogF0L57OdiI7VohqsAk8lJKaqTdLx8ipgvkr0uUv7X+oL2BC13EcVj7yyzZt8nbWKsdJoqE/GG/hm43gpNbxlY1QRiFxCAXwI0VqnyjFg= 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=W2sv+4NK; arc=none smtp.client-ip=170.10.129.124 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="W2sv+4NK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1743593035; 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=/KWPVDjJCugQVxRyMdQMO4pqMQ/vWo7Ji66wG+/Klyw=; b=W2sv+4NK6hTnCRMT+GnUwRukk1F5afkEPU9Dbqb35WDA2xVoH/Jqai1MeoWY7Yp1f7P6Uy pgs9qW7HCBxBXieqTJaNWgBfwcYnBhYDhrux7H9Uoe9oW/ohFfh+oCHEC2gq2sfwlZqgQh MYpYW8zgM39xOYYB5+kgjkP94OleQgs= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-615-lfoNxvcOMzG1vRUDc15PVA-1; Wed, 02 Apr 2025 07:23:50 -0400 X-MC-Unique: lfoNxvcOMzG1vRUDc15PVA-1 X-Mimecast-MFC-AGG-ID: lfoNxvcOMzG1vRUDc15PVA_1743593029 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D1E02195608F; Wed, 2 Apr 2025 11:23:48 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.44.34.147]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 6F962195609D; Wed, 2 Apr 2025 11:23:45 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 2 Apr 2025 13:23:14 +0200 (CEST) Date: Wed, 2 Apr 2025 13:23:09 +0200 From: Oleg Nesterov To: Sebastian Sewior Cc: Andrii Nakryiko , Steven Rostedt , Peter Ziljstra , Alexei Starovoitov , Andrii Nakryiko , bpf , Jiri Olsa , Masami Hiramatsu Subject: Re: uprobe splat in PREEMP_RT Message-ID: <20250402112308.GF22091@redhat.com> References: <20250401172225.06b01b22@gandalf.local.home> <20250402103326.GD22091@redhat.com> <20250402105746.FMPvRBwL@linutronix.de> Precedence: bulk X-Mailing-List: bpf@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: <20250402105746.FMPvRBwL@linutronix.de> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On 04/02, Sebastian Sewior wrote: > > On 2025-04-02 12:33:55 [+0200], Oleg Nesterov wrote: > > > > The "writer" ri_timer() can't race with itself, right? > > On PREEMPT_RT the timer could be preempted by a task with higher > priority and invoke hprobe_expire() somewhere else. This is clear, but ri_timer() still can not race with itself, no? Oleg.