| Message ID | 20201124095259.58755-15-songmuchun@bytedance.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Free some vmemmap pages of hugetlb page | expand |
> -----Original Message----- > From: Muchun Song [mailto:songmuchun@bytedance.com] > Sent: Tuesday, November 24, 2020 10:53 PM > 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 > (Barry Song) <song.bao.hua@hisilicon.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 v6 14/16] mm/hugetlb: Add a kernel parameter > hugetlb_free_vmemmap > > Add a kernel parameter hugetlb_free_vmemmap to disable the feature of > freeing unused vmemmap pages associated with each hugetlb page on boot. > > Signed-off-by: Muchun Song <songmuchun@bytedance.com> > --- > Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ > Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++ > mm/hugetlb_vmemmap.c | 19 > ++++++++++++++++++- > 3 files changed, 30 insertions(+), 1 deletion(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > b/Documentation/admin-guide/kernel-parameters.txt > index 5debfe238027..d28c3acde965 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -1551,6 +1551,15 @@ > Documentation/admin-guide/mm/hugetlbpage.rst. > Format: size[KMG] > > + hugetlb_free_vmemmap= > + [KNL] When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, > + this controls freeing unused vmemmap pages associated > + with each HugeTLB page. > + Format: { on | off (default) } > + > + on: enable the feature > + off: disable the feature > + We've a parameter here. but wouldn't it be applied to "x86/mm/64/:disable Pmd page mapping of vmemmap" as well? If (hugetlb_free_vmemmap_enabled) Do Basepage mapping? > hung_task_panic= > [KNL] Should the hung task detector generate panics. > Format: 0 | 1 > diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst > b/Documentation/admin-guide/mm/hugetlbpage.rst > index f7b1c7462991..6a8b57f6d3b7 100644 > --- a/Documentation/admin-guide/mm/hugetlbpage.rst > +++ b/Documentation/admin-guide/mm/hugetlbpage.rst > @@ -145,6 +145,9 @@ default_hugepagesz > > will all result in 256 2M huge pages being allocated. Valid default > huge page size is architecture dependent. > +hugetlb_free_vmemmap > + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables > freeing > + unused vmemmap pages associated each HugeTLB page. > > When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages`` > indicates the current number of pre-allocated huge pages of the default size. > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > index 509ca451e232..b2222f8d1245 100644 > --- a/mm/hugetlb_vmemmap.c > +++ b/mm/hugetlb_vmemmap.c > @@ -131,6 +131,22 @@ typedef void (*vmemmap_pte_remap_func_t)(struct > page *reuse, pte_t *ptep, > unsigned long start, unsigned long end, > void *priv); > > +static bool hugetlb_free_vmemmap_enabled __initdata; > + > +static int __init early_hugetlb_free_vmemmap_param(char *buf) > +{ > + if (!buf) > + return -EINVAL; > + > + if (!strcmp(buf, "on")) > + hugetlb_free_vmemmap_enabled = true; > + else if (strcmp(buf, "off")) > + return -EINVAL; > + > + return 0; > +} > +early_param("hugetlb_free_vmemmap", > early_hugetlb_free_vmemmap_param); > + > static inline unsigned int vmemmap_pages_per_hpage(struct hstate *h) > { > return free_vmemmap_pages_per_hpage(h) + RESERVE_VMEMMAP_NR; > @@ -322,7 +338,8 @@ void __init hugetlb_vmemmap_init(struct hstate *h) > unsigned int order = huge_page_order(h); > unsigned int vmemmap_pages; > > - if (!is_power_of_2(sizeof(struct page))) { > + if (!is_power_of_2(sizeof(struct page)) || > + !hugetlb_free_vmemmap_enabled) { > pr_info("disable freeing vmemmap pages for %s\n", h->name); > return; > } > -- > 2.11.0 Thanks Barry
On Tue, Nov 24, 2020 at 6:54 PM Song Bao Hua (Barry Song) <song.bao.hua@hisilicon.com> wrote: > > > > > -----Original Message----- > > From: Muchun Song [mailto:songmuchun@bytedance.com] > > Sent: Tuesday, November 24, 2020 10:53 PM > > 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 > > (Barry Song) <song.bao.hua@hisilicon.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 v6 14/16] mm/hugetlb: Add a kernel parameter > > hugetlb_free_vmemmap > > > > Add a kernel parameter hugetlb_free_vmemmap to disable the feature of > > freeing unused vmemmap pages associated with each hugetlb page on boot. > > > > Signed-off-by: Muchun Song <songmuchun@bytedance.com> > > --- > > Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ > > Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++ > > mm/hugetlb_vmemmap.c | 19 > > ++++++++++++++++++- > > 3 files changed, 30 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > > b/Documentation/admin-guide/kernel-parameters.txt > > index 5debfe238027..d28c3acde965 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -1551,6 +1551,15 @@ > > Documentation/admin-guide/mm/hugetlbpage.rst. > > Format: size[KMG] > > > > + hugetlb_free_vmemmap= > > + [KNL] When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, > > + this controls freeing unused vmemmap pages associated > > + with each HugeTLB page. > > + Format: { on | off (default) } > > + > > + on: enable the feature > > + off: disable the feature > > + > > We've a parameter here. but wouldn't it be applied to "x86/mm/64/:disable > Pmd page mapping of vmemmap" as well? > If (hugetlb_free_vmemmap_enabled) > Do Basepage mapping? Oh, yeah, we can. Thanks. > > > hung_task_panic= > > [KNL] Should the hung task detector generate panics. > > Format: 0 | 1 > > diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst > > b/Documentation/admin-guide/mm/hugetlbpage.rst > > index f7b1c7462991..6a8b57f6d3b7 100644 > > --- a/Documentation/admin-guide/mm/hugetlbpage.rst > > +++ b/Documentation/admin-guide/mm/hugetlbpage.rst > > @@ -145,6 +145,9 @@ default_hugepagesz > > > > will all result in 256 2M huge pages being allocated. Valid default > > huge page size is architecture dependent. > > +hugetlb_free_vmemmap > > + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables > > freeing > > + unused vmemmap pages associated each HugeTLB page. > > > > When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages`` > > indicates the current number of pre-allocated huge pages of the default size. > > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > > index 509ca451e232..b2222f8d1245 100644 > > --- a/mm/hugetlb_vmemmap.c > > +++ b/mm/hugetlb_vmemmap.c > > @@ -131,6 +131,22 @@ typedef void (*vmemmap_pte_remap_func_t)(struct > > page *reuse, pte_t *ptep, > > unsigned long start, unsigned long end, > > void *priv); > > > > +static bool hugetlb_free_vmemmap_enabled __initdata; > > + > > +static int __init early_hugetlb_free_vmemmap_param(char *buf) > > +{ > > + if (!buf) > > + return -EINVAL; > > + > > + if (!strcmp(buf, "on")) > > + hugetlb_free_vmemmap_enabled = true; > > + else if (strcmp(buf, "off")) > > + return -EINVAL; > > + > > + return 0; > > +} > > +early_param("hugetlb_free_vmemmap", > > early_hugetlb_free_vmemmap_param); > > + > > static inline unsigned int vmemmap_pages_per_hpage(struct hstate *h) > > { > > return free_vmemmap_pages_per_hpage(h) + RESERVE_VMEMMAP_NR; > > @@ -322,7 +338,8 @@ void __init hugetlb_vmemmap_init(struct hstate *h) > > unsigned int order = huge_page_order(h); > > unsigned int vmemmap_pages; > > > > - if (!is_power_of_2(sizeof(struct page))) { > > + if (!is_power_of_2(sizeof(struct page)) || > > + !hugetlb_free_vmemmap_enabled) { > > pr_info("disable freeing vmemmap pages for %s\n", h->name); > > return; > > } > > -- > > 2.11.0 > > Thanks > Barry >
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 5debfe238027..d28c3acde965 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1551,6 +1551,15 @@ Documentation/admin-guide/mm/hugetlbpage.rst. Format: size[KMG] + hugetlb_free_vmemmap= + [KNL] When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, + this controls freeing unused vmemmap pages associated + with each HugeTLB page. + Format: { on | off (default) } + + on: enable the feature + off: disable the feature + hung_task_panic= [KNL] Should the hung task detector generate panics. Format: 0 | 1 diff --git a/Documentation/admin-guide/mm/hugetlbpage.rst b/Documentation/admin-guide/mm/hugetlbpage.rst index f7b1c7462991..6a8b57f6d3b7 100644 --- a/Documentation/admin-guide/mm/hugetlbpage.rst +++ b/Documentation/admin-guide/mm/hugetlbpage.rst @@ -145,6 +145,9 @@ default_hugepagesz will all result in 256 2M huge pages being allocated. Valid default huge page size is architecture dependent. +hugetlb_free_vmemmap + When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables freeing + unused vmemmap pages associated each HugeTLB page. When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages`` indicates the current number of pre-allocated huge pages of the default size. diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 509ca451e232..b2222f8d1245 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -131,6 +131,22 @@ typedef void (*vmemmap_pte_remap_func_t)(struct page *reuse, pte_t *ptep, unsigned long start, unsigned long end, void *priv); +static bool hugetlb_free_vmemmap_enabled __initdata; + +static int __init early_hugetlb_free_vmemmap_param(char *buf) +{ + if (!buf) + return -EINVAL; + + if (!strcmp(buf, "on")) + hugetlb_free_vmemmap_enabled = true; + else if (strcmp(buf, "off")) + return -EINVAL; + + return 0; +} +early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param); + static inline unsigned int vmemmap_pages_per_hpage(struct hstate *h) { return free_vmemmap_pages_per_hpage(h) + RESERVE_VMEMMAP_NR; @@ -322,7 +338,8 @@ void __init hugetlb_vmemmap_init(struct hstate *h) unsigned int order = huge_page_order(h); unsigned int vmemmap_pages; - if (!is_power_of_2(sizeof(struct page))) { + if (!is_power_of_2(sizeof(struct page)) || + !hugetlb_free_vmemmap_enabled) { pr_info("disable freeing vmemmap pages for %s\n", h->name); return; }
Add a kernel parameter hugetlb_free_vmemmap to disable the feature of freeing unused vmemmap pages associated with each hugetlb page on boot. Signed-off-by: Muchun Song <songmuchun@bytedance.com> --- Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++ Documentation/admin-guide/mm/hugetlbpage.rst | 3 +++ mm/hugetlb_vmemmap.c | 19 ++++++++++++++++++- 3 files changed, 30 insertions(+), 1 deletion(-)