From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH v4 04/18] kunit: test: add kunit_stream a std::stream like logger Date: Fri, 17 May 2019 10:58:41 -0700 Message-ID: <20190517175841.F3396216FD@mail.kernel.org> References: <20190514221711.248228-1-brendanhiggins@google.com> <20190514221711.248228-5-brendanhiggins@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190514221711.248228-5-brendanhiggins-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, jpoimboe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, keescook-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, kieran.bingham-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, mcgrof-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, shuah-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, tytso-3s7WtUTddSA@public.gmane.org, yamada.masahiro-uWyLwvC0a2jby3iVrkZq2A@public.gmane.org Cc: pmladek-IBi9RG/b67k@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, amir73il-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Brendan Higgins , dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, Alexander.Levin-0li6OtcxBFHby3iVrkZq2A@public.gmane.org, linux-kselftest-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, khilman-rdvid1DuHRBWk0Htik3J/w@public.gmane.org, knut.omang-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, wfg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org, rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, jdike-OPE4K8JWMJJBDgjK7y7TUQ@public.gmane.org, dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kbuild-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Tim.Bird-7U/KSKJipcs@public.gmane.org, linux-um-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org, julia.lawall-L2FTfq7BK8M@public.gmane.org, kunit-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, richard-/L3Ra7n9ekc@public.gmane.org, rdunlap-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, daniel-/w4YWyX8dFk@public.gmane.org, mpe-Gsx/Oe8HsFggBc27wqDAHg@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org Quoting Brendan Higgins (2019-05-14 15:16:57) > diff --git a/kunit/kunit-stream.c b/kunit/kunit-stream.c > new file mode 100644 > index 0000000000000..1884f1b550888 > --- /dev/null > +++ b/kunit/kunit-stream.c > @@ -0,0 +1,152 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * C++ stream style string formatter and printer used in KUnit for outputting > + * KUnit messages. > + * > + * Copyright (C) 2019, Google LLC. > + * Author: Brendan Higgins > + */ > + > +#include > +#include > +#include > + > +static const char *kunit_stream_get_level(struct kunit_stream *this) > +{ > + unsigned long flags; > + const char *level; > + > + spin_lock_irqsave(&this->lock, flags); > + level = this->level; > + spin_unlock_irqrestore(&this->lock, flags); > + > + return level; Please remove this whole function and inline it to the one call-site. > +} > + > +void kunit_stream_set_level(struct kunit_stream *this, const char *level) > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&this->lock, flags); > + this->level = level; > + spin_unlock_irqrestore(&this->lock, flags); I don't get the locking here. What are we protecting against? Are tests running in parallel using the same kunit_stream? If so, why is the level changeable in one call and then adding strings is done in a different function call? It would make sense to combine the level setting and string adding so that it's one atomic operation if it's truly a parallel operation, or remove the locking entirely. > +} > + > +void kunit_stream_add(struct kunit_stream *this, const char *fmt, ...) > +{ > + va_list args; > + struct string_stream *stream = this->internal_stream; > + > + va_start(args, fmt); > + > + if (string_stream_vadd(stream, fmt, args) < 0) > + kunit_err(this->test, "Failed to allocate fragment: %s\n", fmt); > + > + va_end(args); > +} > + > +void kunit_stream_append(struct kunit_stream *this, > + struct kunit_stream *other) > +{ > + struct string_stream *other_stream = other->internal_stream; > + const char *other_content; > + > + other_content = string_stream_get_string(other_stream); > + > + if (!other_content) { > + kunit_err(this->test, > + "Failed to get string from second argument for appending.\n"); > + return; > + } > + > + kunit_stream_add(this, other_content); > +} > + > +void kunit_stream_clear(struct kunit_stream *this) > +{ > + string_stream_clear(this->internal_stream); > +} > + > +void kunit_stream_commit(struct kunit_stream *this) Should this be rather called kunit_stream_flush()? > +{ > + struct string_stream *stream = this->internal_stream; > + struct string_stream_fragment *fragment; > + const char *level; > + char *buf; > + > + level = kunit_stream_get_level(this); > + if (!level) { > + kunit_err(this->test, > + "Stream was committed without a specified log level.\n"); Drop the full-stop? > + level = KERN_ERR; > + kunit_stream_set_level(this, level); > + } > + > + buf = string_stream_get_string(stream); > + if (!buf) { > + kunit_err(this->test, Can you grow a local variable for 'this->test'? It's used many times. Also, 'this' is not very kernel idiomatic. We usually name variables by their type instead of 'this' which is a keyword in other languages. Perhaps it could be named 'kstream'? > + "Could not allocate buffer, dumping stream:\n"); > + list_for_each_entry(fragment, &stream->fragments, node) { > + kunit_err(this->test, fragment->fragment); > + } > + kunit_err(this->test, "\n"); > + goto cleanup; > + } > + > + kunit_printk(level, this->test, buf); > + kfree(buf); > + > +cleanup: > + kunit_stream_clear(this); > +} > + > +static int kunit_stream_init(struct kunit_resource *res, void *context) > +{ > + struct kunit *test = context; > + struct kunit_stream *stream; > + > + stream = kzalloc(sizeof(*stream), GFP_KERNEL); Of course, here it's called 'stream', so maybe it should be 'kstream' here too. > + if (!stream) > + return -ENOMEM; > + > + res->allocation = stream; > + stream->test = test; > + spin_lock_init(&stream->lock); > + stream->internal_stream = new_string_stream(); Can new_string_stream() be renamed to alloc_string_stream()? Sorry, I just see so much C++ isms in here it's hard to read from the kernel developer perspective. > + > + if (!stream->internal_stream) { Nitpick: Please join this to the "allocation" event above instead of keeping it separated. > + kfree(stream); > + return -ENOMEM; > + } > + > + return 0; > +} > + > +static void kunit_stream_free(struct kunit_resource *res) > +{ > + struct kunit_stream *stream = res->allocation; > + > + if (!string_stream_is_empty(stream->internal_stream)) { > + kunit_err(stream->test, > + "End of test case reached with uncommitted stream entries.\n"); > + kunit_stream_commit(stream); > + } > + > + destroy_string_stream(stream->internal_stream); > + kfree(stream); > +} > + > +struct kunit_stream *kunit_new_stream(struct kunit *test) > +{ > + struct kunit_resource *res; > + > + res = kunit_alloc_resource(test, > + kunit_stream_init, > + kunit_stream_free, > + test); > + > + if (res) > + return res->allocation; > + else > + return NULL; Don't have if (...) return ...; else return ..., just return instead of else.