From: Muchun Song <songmuchun@bytedance.com>
To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de,
mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com,
dave.hansen@linux.intel.com, luto@kernel.org,
peterz@infradead.org, viro@zeniv.linux.org.uk,
akpm@linux-foundation.org, paulmck@kernel.org,
mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com,
rdunlap@infradead.org, oneukum@suse.com,
anshuman.khandual@arm.com, jroedel@suse.de,
almasrymina@google.com, rientjes@google.com, willy@infradead.org,
osalvador@suse.de, mhocko@suse.com, song.bao.hua@hisilicon.com,
david@redhat.com
Cc: duanxiongchun@bytedance.com, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org,
Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH v8 12/12] mm/hugetlb: Optimize the code with the help of the compiler
Date: Thu, 10 Dec 2020 11:55:26 +0800 [thread overview]
Message-ID: <20201210035526.38938-13-songmuchun@bytedance.com> (raw)
In-Reply-To: <20201210035526.38938-1-songmuchun@bytedance.com>
We cannot optimize if a "struct page" crosses page boundaries. If
it is true, we can optimize the code with the help of a compiler.
When free_vmemmap_pages_per_hpage() returns zero, most functions are
optimized by the compiler.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
include/linux/hugetlb.h | 3 ++-
mm/hugetlb_vmemmap.c | 3 +++
mm/hugetlb_vmemmap.h | 2 +-
3 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 7295f6b3d55e..adc17765e0e9 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -791,7 +791,8 @@ extern bool hugetlb_free_vmemmap_enabled;
static inline bool is_hugetlb_free_vmemmap_enabled(void)
{
- return hugetlb_free_vmemmap_enabled;
+ return hugetlb_free_vmemmap_enabled &&
+ is_power_of_2(sizeof(struct page));
}
#else
static inline bool is_hugetlb_free_vmemmap_enabled(void)
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 7f0b9e002be4..819ab9bb9298 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -208,6 +208,9 @@ bool hugetlb_free_vmemmap_enabled;
static int __init early_hugetlb_free_vmemmap_param(char *buf)
{
+ if (!is_power_of_2(sizeof(struct page)))
+ return 0;
+
if (!buf)
return -EINVAL;
diff --git a/mm/hugetlb_vmemmap.h b/mm/hugetlb_vmemmap.h
index 0a1c0d33a316..5f5e90c81cd2 100644
--- a/mm/hugetlb_vmemmap.h
+++ b/mm/hugetlb_vmemmap.h
@@ -21,7 +21,7 @@ void free_huge_page_vmemmap(struct hstate *h, struct page *head);
*/
static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h)
{
- return h->nr_free_vmemmap_pages;
+ return h->nr_free_vmemmap_pages && is_power_of_2(sizeof(struct page));
}
#else
static inline void hugetlb_vmemmap_init(struct hstate *h)
--
2.11.0
next prev parent reply other threads:[~2020-12-10 4:01 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 ` Muchun Song [this message]
2020-12-10 10:25 ` [PATCH v8 12/12] mm/hugetlb: Optimize the code with the help of the compiler Oscar Salvador
2020-12-10 12:14 ` [External] " Muchun Song
2020-12-10 13:16 ` Oscar Salvador
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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