From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Battersby Subject: Re: [PATCH v2 2/9] dmapool: cleanup error messages Date: Fri, 3 Aug 2018 09:41:55 -0400 Message-ID: <7a943124-c65e-f0ed-cc5c-20b23f021505@cybernetics.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Andy Shevchenko Cc: linux-scsi , Chaitra P B , Suganath Prabu Subramani , Sathya Prakash , Matthew Wilcox , linux-mm , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, MPT-FusionLinux.pdl-dY08KVG/lbpWk0Htik3J/w@public.gmane.org, Christoph Hellwig List-Id: linux-scsi@vger.kernel.org T24gMDgvMDMvMjAxOCAwNDo1NiBBTSwgQW5keSBTaGV2Y2hlbmtvIHdyb3RlOgo+IE9uIFRodSwg QXVnIDIsIDIwMTggYXQgMTA6NTcgUE0sIFRvbnkgQmF0dGVyc2J5IDx0b255YkBjeWJlcm5ldGlj cy5jb20+IHdyb3RlOgo+PiBSZW1vdmUgY29kZSBkdXBsaWNhdGlvbiBpbiBlcnJvciBtZXNzYWdl cy4gIEl0IGlzIG5vdyBzYWZlIHRvIHBhcyBhIE5VTEwKPj4gZGV2IHRvIGRldl9lcnIoKSwgc28g dGhlIGNoZWNrcyB0byBhdm9pZCBkb2luZyBzbyBhcmUgbm8gbG9uZ2VyCj4+IG5lY2Vzc2FyeS4K Pj4KPj4gRXhhbXBsZToKPj4KPj4gRXJyb3IgbWVzc2FnZSB3aXRoIGRldiAhPSBOVUxMOgo+PiAg IG1wdDNzYXMgMDAwMDowMjowMC4wOiBkbWFfcG9vbF9kZXN0cm95IGNoYWluIHBvb2wsIChfX19f cHRydmFsX19fXykgYnVzeQo+Pgo+PiBTYW1lIGVycm9yIG1lc3NhZ2Ugd2l0aCBkZXYgPT0gTlVM TCBiZWZvcmUgcGF0Y2g6Cj4+ICAgZG1hX3Bvb2xfZGVzdHJveSBjaGFpbiBwb29sLCAoX19fX3B0 cnZhbF9fX18pIGJ1c3kKPj4KPj4gU2FtZSBlcnJvciBtZXNzYWdlIHdpdGggZGV2ID09IE5VTEwg YWZ0ZXIgcGF0Y2g6Cj4+ICAgKE5VTEwgZGV2aWNlICopOiBkbWFfcG9vbF9kZXN0cm95IGNoYWlu IHBvb2wsIChfX19fcHRydmFsX19fXykgYnVzeQo+IEhhdmUgeW91IGNoZWNrZWQgYSBoaXN0b3J5 IG9mIHRoaXM/Cj4KPiBJJ20gcHJldHR5IHN1cmUgdGhpcyB3YXMgY3JlYXRlZCBpbiBhbiBvcmRl ciB0byBhdm9pZCBiYWQgbG9va2luZyAoYW5kCj4gaW4gc29tZSBjYXNlcyBmcmlnaHRlbmluZykg Ik5VTEwgZGV2aWNlICoiIHBhcnQuCj4KPiBJZiBpdCBpdCdzIHRoZSBjYXNlLCBJIHdvdWxkIHJh dGhlciBsZWF2ZSBpdCBhcyBpcywgYW5kIGV2ZW4gbm90IHRoZQo+IGNhc2UsIEknbSBzbGlnaHRs eSBtb3JlIGJlbnQgdG8gdGhlIGN1cnJlbnQgc3RhdGUuCj4KSSBkaWQuwqAgImRyaXZlcnMvYmFz ZS9kbWFwb29sLmMiLCBsYXRlciBtb3ZlZCB0byAibW0vZG1hcG9vbC5jIiwgd2FzCmFkZGVkIGlu IGxpbnV4LTIuNi4zLCBmb3Igd2hpY2ggZGV2X2VycigpIGRpZCBub3Qgd29yayB3aWxsIGEgTlVM TCBkZXYsCnNvIHRoZSBjaGVjayB3YXMgbmVjZXNzYXJ5IGJhY2sgdGhlbi7CoCBJIGFncmVlIHRo YXQgdGhlIChOVUxMIGRldmljZSAqKToKYml0IGlzIHVnbHksIGJ1dCB0aGVzZSBtZXNzYWdlcyBz aG91bGQgYmUgcHJpbnRlZCBvbmx5IGFmdGVyIGEga2VybmVsCmJ1Zywgc28gaXQgaXMgbm90IGxp a2UgdGhleSB3aWxsIGJlIG1ha2luZyBhIHJlZ3VsYXIgYXBwZWFyYW5jZSBpbgpkbWVzZy7CoCBD b25zaWRlcmluZyB0aGF0LCBJIHRoaW5rIHRoYXQgaXQgaXMgYmV0dGVyIHRvIGtlZXAgaXQgc2lt cGxlLgoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KaW9t bXUgbWFpbGluZyBsaXN0CmlvbW11QGxpc3RzLmxpbnV4LWZvdW5kYXRpb24ub3JnCmh0dHBzOi8v bGlzdHMubGludXhmb3VuZGF0aW9uLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2lvbW11 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f198.google.com (mail-qt0-f198.google.com [209.85.216.198]) by kanga.kvack.org (Postfix) with ESMTP id 55C456B0005 for ; Fri, 3 Aug 2018 09:41:59 -0400 (EDT) Received: by mail-qt0-f198.google.com with SMTP id c6-v6so4277656qta.6 for ; Fri, 03 Aug 2018 06:41:59 -0700 (PDT) Received: from mail.cybernetics.com (mail.cybernetics.com. [173.71.130.66]) by mx.google.com with ESMTPS id i3-v6si445147qvg.215.2018.08.03.06.41.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 03 Aug 2018 06:41:58 -0700 (PDT) Subject: Re: [PATCH v2 2/9] dmapool: cleanup error messages References: From: Tony Battersby Message-ID: <7a943124-c65e-f0ed-cc5c-20b23f021505@cybernetics.com> Date: Fri, 3 Aug 2018 09:41:55 -0400 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: owner-linux-mm@kvack.org List-ID: To: Andy Shevchenko Cc: Matthew Wilcox , Christoph Hellwig , Marek Szyprowski , Sathya Prakash , Chaitra P B , Suganath Prabu Subramani , iommu@lists.linux-foundation.org, linux-mm , linux-scsi , MPT-FusionLinux.pdl@broadcom.com On 08/03/2018 04:56 AM, Andy Shevchenko wrote: > On Thu, Aug 2, 2018 at 10:57 PM, Tony Battersby wrote: >> Remove code duplication in error messages. It is now safe to pas a NULL >> dev to dev_err(), so the checks to avoid doing so are no longer >> necessary. >> >> Example: >> >> Error message with dev != NULL: >> mpt3sas 0000:02:00.0: dma_pool_destroy chain pool, (____ptrval____) busy >> >> Same error message with dev == NULL before patch: >> dma_pool_destroy chain pool, (____ptrval____) busy >> >> Same error message with dev == NULL after patch: >> (NULL device *): dma_pool_destroy chain pool, (____ptrval____) busy > Have you checked a history of this? > > I'm pretty sure this was created in an order to avoid bad looking (and > in some cases frightening) "NULL device *" part. > > If it it's the case, I would rather leave it as is, and even not the > case, I'm slightly more bent to the current state. > I did.A "drivers/base/dmapool.c", later moved to "mm/dmapool.c", was added in linux-2.6.3, for which dev_err() did not work will a NULL dev, so the check was necessary back then.A I agree that the (NULL device *): bit is ugly, but these messages should be printed only after a kernel bug, so it is not like they will be making a regular appearance in dmesg.A Considering that, I think that it is better to keep it simple.