From: Gavin Shan <gshan@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
david@redhat.com, osalvador@suse.de, gregkh@linuxfoundation.org,
rafael@kernel.org, dakr@kernel.org
Subject: Re: [PATCH 1/2] drivers/base/memory: Simplify add_boot_memory_block()
Date: Sat, 15 Feb 2025 09:45:05 +1000 [thread overview]
Message-ID: <a33fcf3f-0694-427a-b10c-e99a50d36e02@redhat.com> (raw)
In-Reply-To: <20250214145725.708746506f5937acc96783be@linux-foundation.org>
On 2/15/25 8:57 AM, Andrew Morton wrote:
> On Fri, 14 Feb 2025 16:35:03 +1000 Gavin Shan <gshan@redhat.com> wrote:
>
>> It's unnecessary to keep the variable @section_count in the function
>> because the device for the specific memory block will be added if
>> any of its memory section is present. The variable @section_count
>> records the number of present memory sections in the specific memory
>> block, which isn't needed.
>>
>> Simplify the function by dropping the variable @section_count. No
>> functional change intended.
>>
>> ...
>>
>> static int __init add_boot_memory_block(unsigned long base_section_nr)
>> {
>> - int section_count = 0;
>> unsigned long nr;
>>
>> for (nr = base_section_nr; nr < base_section_nr + sections_per_block;
>
> mm/sparse.c has a for_each_present_section_nr() - is that usable here?
>
It should be fine to use it. I will add one preparatory patch to expose
for_each_present_section_nr(). With it, the nested if statements can also
be avoided, Something like below.
for_each_present_section_nr(base_section_nr - 1, nr) {
if (nr >= base_section_nr + sections_per_block)
break;
return add_memory_block(memory_block_id(nr), MEM_ONLINE, NULL, NULL);
}
return 0;
>> - nr++)
>> - if (present_section_nr(nr))
>> - section_count++;
>> + nr++) {
>> + if (present_section_nr(nr)) {
>> + return add_memory_block(memory_block_id(base_section_nr),
>> + MEM_ONLINE, NULL, NULL);
>> + }
>> + }
>>
Thanks,
Gavin
next prev parent reply other threads:[~2025-02-14 23:45 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-14 6:35 [PATCH 0/2] drivers/base/memory: Two cleanups Gavin Shan
2025-02-14 6:35 ` [PATCH 1/2] drivers/base/memory: Simplify add_boot_memory_block() Gavin Shan
2025-02-14 7:53 ` David Hildenbrand
2025-02-14 23:48 ` Gavin Shan
2025-02-14 22:57 ` Andrew Morton
2025-02-14 23:45 ` Gavin Shan [this message]
2025-02-14 6:35 ` [PATCH 2/2] drivers/base/memory: Correct the field name in the header Gavin Shan
2025-02-14 7:54 ` David Hildenbrand
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