From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2517054F93; Mon, 29 Jan 2024 09:24:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706520277; cv=none; b=J9BXUB33LQF1JwDZfYd07jKDDQuRkX40fW6XULlS0BxFvRPIGKFHNNJbT8JNSlUQTCmZSvjhReXDH71p5ThPLSF5W5ZtQpZV11P6XRw6590x2OngZnRDDcxb35ESxUnQ8QTYp209uLXy2vbj7wOOOYKdhdpNn7p5UAb9v+KXb+w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706520277; c=relaxed/simple; bh=inmOTze7uKfZeWIoyGwST8hZ+d0IPucCCcqmZ34CTwM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RSaub6YEpF49Y5VZS9ojZ54+jfYWYJR0RoOmNL7zwrOEEX3548X0A/DVzQ6Y8bljG8NWn3su5xFC5PNHdYNCEeQs42ufOEA62JagMQM1tuhBjxfmWFHAaWU98o+SVJwDMQxTY4jCdkhyj99xI42nxdjfB6VdDw1DAmdqz5lUsfQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 132871FB; Mon, 29 Jan 2024 01:25:18 -0800 (PST) Received: from [10.162.42.11] (a077893.blr.arm.com [10.162.42.11]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5B6393F762; Mon, 29 Jan 2024 01:24:23 -0800 (PST) Message-ID: <0a71c87a-ae2c-4a61-8adb-3a51d6369b99@arm.com> Date: Mon, 29 Jan 2024 14:54:20 +0530 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC v3 06/35] mm: cma: Make CMA_ALLOC_SUCCESS/FAIL count the number of pages Content-Language: en-US To: Alexandru Elisei , catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org References: <20240125164256.4147-1-alexandru.elisei@arm.com> <20240125164256.4147-7-alexandru.elisei@arm.com> From: Anshuman Khandual In-Reply-To: <20240125164256.4147-7-alexandru.elisei@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 1/25/24 22:12, Alexandru Elisei wrote: > The CMA_ALLOC_SUCCESS, respectively CMA_ALLOC_FAIL, are increased by one > after each cma_alloc() function call. This is done even though cma_alloc() > can allocate an arbitrary number of CMA pages. When looking at > /proc/vmstat, the number of successful (or failed) cma_alloc() calls > doesn't tell much with regards to how many CMA pages were allocated via > cma_alloc() versus via the page allocator (regular allocation request or > PCP lists refill). > > This can also be rather confusing to a user who isn't familiar with the > code, since the unit of measurement for nr_free_cma is the number of pages, > but cma_alloc_success and cma_alloc_fail count the number of cma_alloc() > function calls. > > Let's make this consistent, and arguably more useful, by having > CMA_ALLOC_SUCCESS count the number of successfully allocated CMA pages, and > CMA_ALLOC_FAIL count the number of pages the cma_alloc() failed to > allocate. > > For users that wish to track the number of cma_alloc() calls, there are > tracepoints for that already implemented. > > Signed-off-by: Alexandru Elisei > --- > mm/cma.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/cma.c b/mm/cma.c > index f49c95f8ee37..dbf7fe8cb1bd 100644 > --- a/mm/cma.c > +++ b/mm/cma.c > @@ -517,10 +517,10 @@ struct page *cma_alloc(struct cma *cma, unsigned long count, > pr_debug("%s(): returned %p\n", __func__, page); > out: > if (page) { > - count_vm_event(CMA_ALLOC_SUCCESS); > + count_vm_events(CMA_ALLOC_SUCCESS, count); > cma_sysfs_account_success_pages(cma, count); > } else { > - count_vm_event(CMA_ALLOC_FAIL); > + count_vm_events(CMA_ALLOC_FAIL, count); > if (cma) > cma_sysfs_account_fail_pages(cma, count); > } Without getting into the merits of this patch - which is actually trying to do semantics change to /proc/vmstat, wondering how is this even related to this particular series ? If required this could be debated on it's on separately.