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[217.70.183.199]) by mx.google.com with ESMTPS id u12si5715898wmc.129.2019.02.03.10.18.05 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 03 Feb 2019 10:18:06 -0800 (PST) Received-SPF: neutral (google.com: 217.70.183.199 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) client-ip=217.70.183.199; Authentication-Results: mx.google.com; spf=neutral (google.com: 217.70.183.199 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) smtp.mailfrom=alex@ghiti.fr X-Originating-IP: 79.86.19.127 Received: from [192.168.0.11] (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay9-d.mail.gandi.net (Postfix) with ESMTPSA id 31D30FF802; Sun, 3 Feb 2019 18:17:57 +0000 (UTC) Subject: Re: [PATCH] hugetlb: allow to free gigantic pages regardless of the configuration To: akpm@linux-foundation.org, Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , x86@kernel.org, Alexander Viro , Mike Kravetz , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Cc: linux-riscv@lists.infradead.org, hch@infradead.org References: <20190117183953.5990-1-aghiti@upmem.com> From: Alex Ghiti Message-ID: <65c8ebc7-fc77-bd19-616d-e950ff6b080d@ghiti.fr> Date: Sun, 3 Feb 2019 13:17:56 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190117183953.5990-1-aghiti@upmem.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Content-Language: sv-FI X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 1/17/19 1:39 PM, Alexandre Ghiti wrote: > From: Alexandre Ghiti > > On systems without CMA or (MEMORY_ISOLATION && COMPACTION) activated but > that support gigantic pages, boottime reserved gigantic pages can not be > freed at all. This patchs simply enables the possibility to hand back > those pages to memory allocator. > > This commit then renames gigantic_page_supported and > ARCH_HAS_GIGANTIC_PAGE to make them more accurate. Indeed, those values > being false does not mean that the system cannot use gigantic pages: it > just means that runtime allocation of gigantic pages is not supported, > one can still allocate boottime gigantic pages if the architecture supports > it. > > Signed-off-by: Alexandre Ghiti > --- > > - Compiled on all architectures > - Tested on riscv architecture > > arch/arm64/Kconfig | 2 +- > arch/arm64/include/asm/hugetlb.h | 7 +++-- > arch/powerpc/include/asm/book3s/64/hugetlb.h | 4 +-- > arch/powerpc/platforms/Kconfig.cputype | 2 +- > arch/s390/Kconfig | 2 +- > arch/s390/include/asm/hugetlb.h | 7 +++-- > arch/x86/Kconfig | 2 +- > arch/x86/include/asm/hugetlb.h | 7 +++-- > fs/Kconfig | 2 +- > include/linux/gfp.h | 2 +- > mm/hugetlb.c | 43 +++++++++++++++------------- > mm/page_alloc.c | 4 +-- > 12 files changed, 48 insertions(+), 36 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index a4168d366127..18239cbd7fcd 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -18,7 +18,7 @@ config ARM64 > select ARCH_HAS_FAST_MULTIPLIER > select ARCH_HAS_FORTIFY_SOURCE > select ARCH_HAS_GCOV_PROFILE_ALL > - select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA > + select ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION if (MEMORY_ISOLATION && COMPACTION) || CMA > select ARCH_HAS_KCOV > select ARCH_HAS_MEMBARRIER_SYNC_CORE > select ARCH_HAS_PTE_SPECIAL > diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h > index fb6609875455..797fc77eabcd 100644 > --- a/arch/arm64/include/asm/hugetlb.h > +++ b/arch/arm64/include/asm/hugetlb.h > @@ -65,8 +65,11 @@ extern void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr, > > #include > > -#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE > -static inline bool gigantic_page_supported(void) { return true; } > +#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION > +static inline bool gigantic_page_runtime_allocation_supported(void) > +{ > + return true; > +} > #endif > > #endif /* __ASM_HUGETLB_H */ > diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h > index 5b0177733994..7711f0e2c7e5 100644 > --- a/arch/powerpc/include/asm/book3s/64/hugetlb.h > +++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h > @@ -32,8 +32,8 @@ static inline int hstate_get_psize(struct hstate *hstate) > } > } > > -#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE > -static inline bool gigantic_page_supported(void) > +#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION > +static inline bool gigantic_page_runtime_allocation_supported(void) > { > return true; > } > diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype > index 8c7464c3f27f..779e06bac697 100644 > --- a/arch/powerpc/platforms/Kconfig.cputype > +++ b/arch/powerpc/platforms/Kconfig.cputype > @@ -319,7 +319,7 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK > config PPC_RADIX_MMU > bool "Radix MMU Support" > depends on PPC_BOOK3S_64 > - select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA > + select ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION if (MEMORY_ISOLATION && COMPACTION) || CMA > default y > help > Enable support for the Power ISA 3.0 Radix style MMU. Currently this > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > index ed554b09eb3f..6776eef6a9ae 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -69,7 +69,7 @@ config S390 > select ARCH_HAS_ELF_RANDOMIZE > select ARCH_HAS_FORTIFY_SOURCE > select ARCH_HAS_GCOV_PROFILE_ALL > - select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA > + select ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION if (MEMORY_ISOLATION && COMPACTION) || CMA > select ARCH_HAS_KCOV > select ARCH_HAS_PTE_SPECIAL > select ARCH_HAS_SET_MEMORY > diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h > index 2d1afa58a4b6..57c952f5388e 100644 > --- a/arch/s390/include/asm/hugetlb.h > +++ b/arch/s390/include/asm/hugetlb.h > @@ -116,7 +116,10 @@ static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot) > return pte_modify(pte, newprot); > } > > -#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE > -static inline bool gigantic_page_supported(void) { return true; } > +#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION > +static inline bool gigantic_page_runtime_allocation_supported(void) > +{ > + return true; > +} > #endif > #endif /* _ASM_S390_HUGETLB_H */ > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 6185d4f33296..a88f5a4311c9 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -23,7 +23,7 @@ config X86_64 > def_bool y > depends on 64BIT > # Options that are inherently 64-bit kernel only: > - select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA > + select ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION if (MEMORY_ISOLATION && COMPACTION) || CMA > select ARCH_SUPPORTS_INT128 > select ARCH_USE_CMPXCHG_LOCKREF > select HAVE_ARCH_SOFT_DIRTY > diff --git a/arch/x86/include/asm/hugetlb.h b/arch/x86/include/asm/hugetlb.h > index 7469d321f072..5a5e7119ced4 100644 > --- a/arch/x86/include/asm/hugetlb.h > +++ b/arch/x86/include/asm/hugetlb.h > @@ -17,8 +17,11 @@ static inline void arch_clear_hugepage_flags(struct page *page) > { > } > > -#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE > -static inline bool gigantic_page_supported(void) { return true; } > +#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION > +static inline bool gigantic_page_runtime_allocation_supported(void) > +{ > + return true; > +} > #endif > > #endif /* _ASM_X86_HUGETLB_H */ > diff --git a/fs/Kconfig b/fs/Kconfig > index ac474a61be37..4192d1fde0f0 100644 > --- a/fs/Kconfig > +++ b/fs/Kconfig > @@ -207,7 +207,7 @@ config HUGETLB_PAGE > config MEMFD_CREATE > def_bool TMPFS || HUGETLBFS > > -config ARCH_HAS_GIGANTIC_PAGE > +config ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION > bool > > source "fs/configfs/Kconfig" > diff --git a/include/linux/gfp.h b/include/linux/gfp.h > index 5f5e25fd6149..79ff86fabd42 100644 > --- a/include/linux/gfp.h > +++ b/include/linux/gfp.h > @@ -589,8 +589,8 @@ static inline bool pm_suspended_storage(void) > /* The below functions must be run on a range from a single zone. */ > extern int alloc_contig_range(unsigned long start, unsigned long end, > unsigned migratetype, gfp_t gfp_mask); > -extern void free_contig_range(unsigned long pfn, unsigned nr_pages); > #endif > +extern void free_contig_range(unsigned long pfn, unsigned int nr_pages); > > #ifdef CONFIG_CMA > /* CMA stuff */ > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 745088810965..9893ba26b3b8 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1035,7 +1035,6 @@ static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed) > ((node = hstate_next_node_to_free(hs, mask)) || 1); \ > nr_nodes--) > > -#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE > static void destroy_compound_gigantic_page(struct page *page, > unsigned int order) > { > @@ -1058,6 +1057,7 @@ static void free_gigantic_page(struct page *page, unsigned int order) > free_contig_range(page_to_pfn(page), 1 << order); > } > > +#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION > static int __alloc_gigantic_page(unsigned long start_pfn, > unsigned long nr_pages, gfp_t gfp_mask) > { > @@ -1143,22 +1143,19 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, > static void prep_new_huge_page(struct hstate *h, struct page *page, int nid); > static void prep_compound_gigantic_page(struct page *page, unsigned int order); > > -#else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */ > -static inline bool gigantic_page_supported(void) { return false; } > +#else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE_RUNTIME_ALLOCATION */ > +static inline bool gigantic_page_runtime_allocation_supported(void) > +{ > + return false; > +} > static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask, > int nid, nodemask_t *nodemask) { return NULL; } > -static inline void free_gigantic_page(struct page *page, unsigned int order) { } > -static inline void destroy_compound_gigantic_page(struct page *page, > - unsigned int order) { } > #endif > > static void update_and_free_page(struct hstate *h, struct page *page) > { > int i; > > - if (hstate_is_gigantic(h) && !gigantic_page_supported()) > - return; > - > h->nr_huge_pages--; > h->nr_huge_pages_node[page_to_nid(page)]--; > for (i = 0; i < pages_per_huge_page(h); i++) { > @@ -2276,13 +2273,20 @@ static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, > } > > #define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages) > -static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count, > +static int set_max_huge_pages(struct hstate *h, unsigned long count, > nodemask_t *nodes_allowed) > { > unsigned long min_count, ret; > > - if (hstate_is_gigantic(h) && !gigantic_page_supported()) > - return h->max_huge_pages; > + if (hstate_is_gigantic(h) && > + !gigantic_page_runtime_allocation_supported()) { > + spin_lock(&hugetlb_lock); > + if (count > persistent_huge_pages(h)) { > + spin_unlock(&hugetlb_lock); > + return -EINVAL; > + } > + goto decrease_pool; > + } > > /* > * Increase the pool size > @@ -2322,6 +2326,7 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count, > goto out; > } > > +decrease_pool: > /* > * Decrease the pool size > * First return free pages to the buddy allocator (being careful > @@ -2350,9 +2355,10 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count, > break; > } > out: > - ret = persistent_huge_pages(h); > + h->max_huge_pages = persistent_huge_pages(h); > spin_unlock(&hugetlb_lock); > - return ret; > + > + return 0; > } > > #define HSTATE_ATTR_RO(_name) \ > @@ -2404,11 +2410,6 @@ static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, > int err; > NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY); > > - if (hstate_is_gigantic(h) && !gigantic_page_supported()) { > - err = -EINVAL; > - goto out; > - } > - > if (nid == NUMA_NO_NODE) { > /* > * global hstate attribute > @@ -2428,7 +2429,9 @@ static ssize_t __nr_hugepages_store_common(bool obey_mempolicy, > } else > nodes_allowed = &node_states[N_MEMORY]; > > - h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed); > + err = set_max_huge_pages(h, count, nodes_allowed); > + if (err) > + goto out; > > if (nodes_allowed != &node_states[N_MEMORY]) > NODEMASK_FREE(nodes_allowed); > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index cde5dac6229a..81b931db85a1 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -8241,8 +8241,9 @@ int alloc_contig_range(unsigned long start, unsigned long end, > pfn_max_align_up(end), migratetype); > return ret; > } > +#endif > > -void free_contig_range(unsigned long pfn, unsigned nr_pages) > +void free_contig_range(unsigned long pfn, unsigned int nr_pages) > { > unsigned int count = 0; > > @@ -8254,7 +8255,6 @@ void free_contig_range(unsigned long pfn, unsigned nr_pages) > } > WARN(count != 0, "%d pages are still in use!\n", count); > } > -#endif > > #ifdef CONFIG_MEMORY_HOTPLUG > /* Hi Andrew, Can you consider this patch for inclusion in mm tree ? It lacks reviews from some arch maintainers and has been reviewed by Mike Kravetz. Tell me if I can do something to help, Thanks, Alex