From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0ED94C83F11 for ; Tue, 29 Aug 2023 00:31:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234509AbjH2Aaz (ORCPT ); Mon, 28 Aug 2023 20:30:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234300AbjH2Aan (ORCPT ); Mon, 28 Aug 2023 20:30:43 -0400 Received: from out-248.mta1.migadu.com (out-248.mta1.migadu.com [IPv6:2001:41d0:203:375::f8]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B02BD10B for ; Mon, 28 Aug 2023 17:30:40 -0700 (PDT) Message-ID: <25be098a-dc41-7907-5590-1835308ebe28@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1693269037; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9IAzTTcmlJQyO6mSLflkzt3IVsbQUOThQfzVBiQYjgE=; b=DPm51MEZctaWaOJT9m6vaXzveCc8r6glQAgwpw6xebEcB1WEmJ9bY0NNlj6jtP3x0A1av0 OY9WOggNlkslYwD2PCp/KWnBVRhsN2Kr5xPSrsQXEDKIm4Vz5vK6NwXV51YmDuaDFr7zcK 7JFWShgPHfEPCgADkJJG0pQ6hBPEhcI= Date: Mon, 28 Aug 2023 20:30:29 -0400 MIME-Version: 1.0 Reply-To: yonghong.song@linux.dev Subject: Re: [PATCH 3/6] bpf: task_group_seq_get_next: fix the skip_if_dup_files check Content-Language: en-US To: Oleg Nesterov Cc: Andrew Morton , Yonghong Song , "Eric W. Biederman" , Linus Torvalds , Daniel Borkmann , Kui-Feng Lee , Andrii Nakryiko , Martin KaFai Lau , bpf@vger.kernel.org, linux-kernel@vger.kernel.org References: <20230825161842.GA16750@redhat.com> <20230825161947.GA16871@redhat.com> <20230825170406.GA16800@redhat.com> <20230827201909.GC28645@redhat.com> <20230828105453.GB19186@redhat.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yonghong Song In-Reply-To: <20230828105453.GB19186@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/28/23 3:54 AM, Oleg Nesterov wrote: > On 08/27, Yonghong Song wrote: >> >> On 8/27/23 1:19 PM, Oleg Nesterov wrote: >>> >>> But. if the group leader M exits then M->files == NULL. And in this case >>> task_seq_get_next() will need to "inspect" all the sub-threads even if they all >>> have the same ->files pointer. >> >> That is correct. I do not have practical experience on how much >> possibility this scenario may happen. I assume it should be very low. > > Yes. I just tried to explain why the ->files check looks confusing to me. > Nevermind. > > Could you review 6/6 as well? I think we can wait patch 6/6 after https://lore.kernel.org/all/20230824143142.GA31222@redhat.com/ is merged. > > Should I fold 1-5 into a single patch? I tried to document every change > and simplify the review, but I do not want to blow the git history. Currently, because patch 6, the whole patch set cannot be tested by bpf CI since it has a build failure: https://github.com/kernel-patches/bpf/pull/5580 I suggest you get patch 1-5 and resubmit with tag like "bpf-next v2" [Patch bpf-next v2 x/5] ... so CI can build with different architectures and compilers to ensure everything builds and runs fine. > > Oleg. >