From: Oscar Salvador <osalvador@suse.de>
To: Muchun Song <songmuchun@bytedance.com>
Cc: Jonathan Corbet <corbet@lwn.net>,
Mike Kravetz <mike.kravetz@oracle.com>,
Thomas Gleixner <tglx@linutronix.de>,
mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com,
dave.hansen@linux.intel.com, luto@kernel.org,
Peter Zijlstra <peterz@infradead.org>,
viro@zeniv.linux.org.uk,
Andrew Morton <akpm@linux-foundation.org>,
paulmck@kernel.org, mchehab+huawei@kernel.org,
pawan.kumar.gupta@linux.intel.com,
Randy Dunlap <rdunlap@infradead.org>,
oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de,
Mina Almasry <almasrymina@google.com>,
David Rientjes <rientjes@google.com>,
Matthew Wilcox <willy@infradead.org>,
Michal Hocko <mhocko@suse.com>,
"Song Bao Hua (Barry Song)" <song.bao.hua@hisilicon.com>,
David Hildenbrand <david@redhat.com>,
Xiongchun duan <duanxiongchun@bytedance.com>,
linux-doc@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
Linux Memory Management List <linux-mm@kvack.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [External] Re: [PATCH v8 12/12] mm/hugetlb: Optimize the code with the help of the compiler
Date: Thu, 10 Dec 2020 14:16:08 +0100 [thread overview]
Message-ID: <20201210131608.GA7811@localhost.localdomain> (raw)
In-Reply-To: <CAMZfGtUQOXmuRumv48MYGCYh_JZn4bMPPz8HW2ExgTPCfFMMnw@mail.gmail.com>
On Thu, Dec 10, 2020 at 08:14:18PM +0800, Muchun Song wrote:
> Yeah, you are right. But if we do this check can make the code simple.
>
> For example, here is a code snippet.
>
> void func(void)
> {
> if (free_vmemmap_pages_per_hpage())
> return;
> /* Do something */
> }
>
> With this patch, the func will be optimized to null when is_power_of_2
> returns false.
>
> void func(void)
> {
> }
>
> Without this patch, the compiler cannot do this optimization.
Ok, I misread the changelog.
So, then is_hugetlb_free_vmemmap_enabled, free_huge_page_vmemmap,
free_vmemmap_pages_per_hpage and hugetlb_vmemmap_init are optimized
out, right?
--
Oscar Salvador
SUSE L3
next prev parent reply other threads:[~2020-12-10 13:17 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-10 3:55 [PATCH v8 00/12] Free some vmemmap pages of HugeTLB page Muchun Song
2020-12-10 3:55 ` [PATCH v8 01/12] mm/memory_hotplug: Factor out bootmem core functions to bootmem_info.c Muchun Song
2020-12-10 3:55 ` [PATCH v8 02/12] mm/hugetlb: Introduce a new config HUGETLB_PAGE_FREE_VMEMMAP Muchun Song
2020-12-10 3:55 ` [PATCH v8 03/12] mm/bootmem_info: Introduce free_bootmem_page helper Muchun Song
2020-12-10 14:15 ` Oscar Salvador
2020-12-10 15:22 ` [External] " Muchun Song
2020-12-10 15:26 ` Muchun Song
2020-12-10 3:55 ` [PATCH v8 04/12] mm/hugetlb: Free the vmemmap pages associated with each HugeTLB page Muchun Song
2020-12-10 14:42 ` Oscar Salvador
2020-12-10 14:44 ` Oscar Salvador
2020-12-10 15:58 ` [External] " Muchun Song
2020-12-10 15:57 ` Muchun Song
2020-12-10 3:55 ` [PATCH v8 05/12] mm/hugetlb: Defer freeing of HugeTLB pages Muchun Song
2020-12-10 3:55 ` [PATCH v8 06/12] mm/hugetlb: Allocate the vmemmap pages associated with each HugeTLB page Muchun Song
2020-12-11 9:35 ` Oscar Salvador
2020-12-11 10:52 ` David Hildenbrand
2020-12-11 13:01 ` [External] " Muchun Song
2020-12-10 3:55 ` [PATCH v8 07/12] mm/hugetlb: Set the PageHWPoison to the raw error page Muchun Song
2020-12-10 11:11 ` Muchun Song
2020-12-11 13:36 ` Oscar Salvador
2020-12-11 14:08 ` [External] " Muchun Song
2020-12-10 3:55 ` [PATCH v8 08/12] mm/hugetlb: Flush work when dissolving hugetlb page Muchun Song
2020-12-10 3:55 ` [PATCH v8 09/12] mm/hugetlb: Add a kernel parameter hugetlb_free_vmemmap Muchun Song
2020-12-10 10:04 ` Oscar Salvador
2020-12-10 12:26 ` [External] " Muchun Song
2020-12-10 3:55 ` [PATCH v8 10/12] mm/hugetlb: Introduce nr_free_vmemmap_pages in the struct hstate Muchun Song
2020-12-10 10:15 ` Oscar Salvador
2020-12-10 12:32 ` [External] " Muchun Song
2020-12-10 3:55 ` [PATCH v8 11/12] mm/hugetlb: Gather discrete indexes of tail page Muchun Song
2020-12-10 3:55 ` [PATCH v8 12/12] mm/hugetlb: Optimize the code with the help of the compiler Muchun Song
2020-12-10 10:25 ` Oscar Salvador
2020-12-10 12:14 ` [External] " Muchun Song
2020-12-10 13:16 ` Oscar Salvador [this message]
2020-12-10 13:29 ` Muchun Song
2020-12-10 16:19 ` Muchun Song
2020-12-10 9:18 ` [PATCH v8 00/12] Free some vmemmap pages of HugeTLB page Oscar Salvador
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