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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF4B8C433E0 for ; Sat, 6 Jun 2020 18:12:45 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 297CF20760 for ; Sat, 6 Jun 2020 18:12:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 297CF20760 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49fSKl1H5KzDqCp for ; Sun, 7 Jun 2020 04:12:43 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=permerror (SPF Permanent Error: Unknown mechanism found: ip:192.40.192.88/32) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by lists.ozlabs.org (Postfix) with ESMTP id 49fSGg0wnpzDqvg for ; Sun, 7 Jun 2020 04:10:02 +1000 (AEST) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 056I9CBj006803; Sat, 6 Jun 2020 13:09:12 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 056I9AdG006802; Sat, 6 Jun 2020 13:09:10 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Sat, 6 Jun 2020 13:09:10 -0500 From: Segher Boessenkool To: Vaibhav Jain Subject: Re: [PATCH v10 6/6] powerpc/papr_scm: Implement support for PAPR_PDSM_HEALTH Message-ID: <20200606180910.GW31009@gate.crashing.org> References: <20200604234136.253703-1-vaibhav@linux.ibm.com> <20200604234136.253703-7-vaibhav@linux.ibm.com> <20200605183655.GP1505637@iweiny-DESK2.sc.intel.com> <87wo4kfk58.fsf@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87wo4kfk58.fsf@linux.ibm.com> User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Santosh Sivaraj , linux-nvdimm@lists.01.org, "Aneesh Kumar K . V" , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Steven Rostedt , Oliver O'Halloran , Dan Williams , Ira Weiny Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Sat, Jun 06, 2020 at 06:04:11PM +0530, Vaibhav Jain wrote: > >> + /* update health struct with various flags derived from health bitmap */ > >> + health = (struct nd_papr_pdsm_health) { > >> + .dimm_unarmed = p->health_bitmap & PAPR_PMEM_UNARMED_MASK, > >> + .dimm_bad_shutdown = p->health_bitmap & PAPR_PMEM_BAD_SHUTDOWN_MASK, > >> + .dimm_bad_restore = p->health_bitmap & PAPR_PMEM_BAD_RESTORE_MASK, > >> + .dimm_encrypted = p->health_bitmap & PAPR_PMEM_ENCRYPTED, > >> + .dimm_locked = p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED, > >> + .dimm_scrubbed = p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED, > > > > Are you sure these work? These are not assignments to a bool so I don't think > > gcc will do what you want here. > Yeah, somehow this slipped by and didnt show up in my tests. I checked > the assembly dump and seems GCC was silently skipping initializing these > fields without making any noise. It's not "skipping" that, it initialises the field to 0, just like your code said it should :-) If you think GCC should warn for this, please open a PR? It is *normal* for bit-fields to be truncated from what is assigned to it, but maybe we could warn for it in the 1-bit case (we currently don't seem to, even when the bit-field type is _Bool). Thanks, Segher