Re: [PATCH v1 1/6] mm: Section numbers use the type "unsigned long"
From: Christophe Leroy <hidden>
Date: 2019-06-15 08:07:26
Also in:
linux-acpi, linux-mm, lkml
Le 14/06/2019 à 21:00, Andrew Morton a écrit :
On Fri, 14 Jun 2019 12:01:09 +0200 David Hildenbrand [off-list ref] wrote:quoted
We are using a mixture of "int" and "unsigned long". Let's make this consistent by using "unsigned long" everywhere. We'll do the same with memory block ids next. ... - int i, ret, section_count = 0; + unsigned long i; ... - unsigned int i; + unsigned long i;Maybe I did too much fortran back in the day, but I think the expectation is that a variable called "i" has type "int". This? s/unsigned long i/unsigned long section_nr/
From my point of view you degrade readability by doing that. section_nr_to_pfn(mem->start_section_nr + section_nr); Three times the word 'section_nr' in one line, is that worth it ? Gives me headache. Codying style says the following, which makes full sense in my opinion: LOCAL variable names should be short, and to the point. If you have some random integer loop counter, it should probably be called ``i``. Calling it ``loop_counter`` is non-productive, if there is no chance of it being mis-understood. What about just naming it 'nr' if we want to use something else than 'i' ? Christophe
quoted hunk ↗ jump to hunk
--- a/drivers/base/memory.c~mm-section-numbers-use-the-type-unsigned-long-fix +++ a/drivers/base/memory.c@@ -131,17 +131,17 @@ static ssize_t phys_index_show(struct de static ssize_t removable_show(struct device *dev, struct device_attribute *attr, char *buf) { - unsigned long i, pfn; + unsigned long section_nr, pfn; int ret = 1; struct memory_block *mem = to_memory_block(dev); if (mem->state != MEM_ONLINE) goto out; - for (i = 0; i < sections_per_block; i++) { - if (!present_section_nr(mem->start_section_nr + i)) + for (section_nr = 0; section_nr < sections_per_block; section_nr++) { + if (!present_section_nr(mem->start_section_nr + section_nr)) continue; - pfn = section_nr_to_pfn(mem->start_section_nr + i); + pfn = section_nr_to_pfn(mem->start_section_nr + section_nr); ret &= is_mem_section_removable(pfn, PAGES_PER_SECTION); }@@ -695,12 +695,12 @@ static int add_memory_block(unsigned lon { int ret, section_count = 0; struct memory_block *mem; - unsigned long i; + unsigned long section_nr; - for (i = base_section_nr; - i < base_section_nr + sections_per_block; - i++) - if (present_section_nr(i)) + for (section_nr = base_section_nr; + section_nr < base_section_nr + sections_per_block; + section_nr++) + if (present_section_nr(section_nr)) section_count++; if (section_count == 0)@@ -823,7 +823,7 @@ static const struct attribute_group *mem */ int __init memory_dev_init(void) { - unsigned long i; + unsigned long section_nr; int ret; int err; unsigned long block_sz;@@ -840,9 +840,9 @@ int __init memory_dev_init(void) * during boot and have been initialized */ mutex_lock(&mem_sysfs_mutex); - for (i = 0; i <= __highest_present_section_nr; - i += sections_per_block) { - err = add_memory_block(i); + for (section_nr = 0; section_nr <= __highest_present_section_nr; + section_nr += sections_per_block) { + err = add_memory_block(section_nr); if (!ret) ret = err; }_