From patchwork Thu Jan 25 16:42:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 13531363 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 76807132C30; Thu, 25 Jan 2024 16:43:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706201027; cv=none; b=kcEfjWJQebgRnZ+L4FqMA8TEnkoCpi2PjcEL5wniKDfmlci7Lrqbfs8mo5XsFNecLRIcolLgg0T4YNLujy26dWOh3sMvI27TSkK6cPbBLwLt/8+anQAK5oGG8JOHwc80aWXpPvl69EIex+qTCElJtA/0zZUSYgJCLgyxuh2dRhE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706201027; c=relaxed/simple; bh=QxhkPMYB/Y18OYFzd/7q0TJlXUBDqmxZYj4MUlWYAXM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=EPhW+HflGFYzRYrQrRcCEz4ctYwjyeYtqL9FWjEHRy2yLVymIyv7hHlpbnx0GG0wRBXHrWq24As20pyqBz76buUt6GOwpuklQn+N0ZryPkrB6CP49mG97algA0v1vqk05kGGgJ3ETvkx1Bag9Ht58P4ICLj8uuDHMZxMnapLlzg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4954D152B; Thu, 25 Jan 2024 08:44:29 -0800 (PST) Received: from e121798.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5543F3F8A4; Thu, 25 Jan 2024 08:43:39 -0800 (PST) From: Alexandru Elisei To: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH RFC v3 10/35] mm: cma: Fast track allocating memory when the pages are free Date: Thu, 25 Jan 2024 16:42:31 +0000 Message-Id: <20240125164256.4147-11-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240125164256.4147-1-alexandru.elisei@arm.com> References: <20240125164256.4147-1-alexandru.elisei@arm.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 If the pages to be allocated are free, take them directly off the buddy allocator, instead of going through alloc_contig_range() and avoiding costly calls to lru_cache_disable(). Only allocations of the same size as the CMA region order are considered, to avoid taking the zone spinlock for too long. Signed-off-by: Alexandru Elisei --- Changes since rfc v2: * New patch. Reworked from the rfc v2 patch #26 ("arm64: mte: Fast track reserving tag storage when the block is free") (David Hildenbrand). include/linux/page-flags.h | 15 ++++++++++++-- mm/Kconfig | 5 +++++ mm/cma.c | 42 ++++++++++++++++++++++++++++++++++---- mm/memory-failure.c | 8 ++++---- mm/page_alloc.c | 23 ++++++++++++--------- 5 files changed, 73 insertions(+), 20 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 735cddc13d20..b7237bce7446 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -575,11 +575,22 @@ TESTSCFLAG(HWPoison, hwpoison, PF_ANY) #define MAGIC_HWPOISON 0x48575053U /* HWPS */ extern void SetPageHWPoisonTakenOff(struct page *page); extern void ClearPageHWPoisonTakenOff(struct page *page); -extern bool take_page_off_buddy(struct page *page); -extern bool put_page_back_buddy(struct page *page); +extern bool PageHWPoisonTakenOff(struct page *page); #else PAGEFLAG_FALSE(HWPoison, hwpoison) +TESTSCFLAG_FALSE(HWPoison, hwpoison) #define __PG_HWPOISON 0 +static inline void SetPageHWPoisonTakenOff(struct page *page) { } +static inline void ClearPageHWPoisonTakenOff(struct page *page) { } +static inline bool PageHWPoisonTakenOff(struct page *page) +{ + return false; +} +#endif + +#ifdef CONFIG_WANTS_TAKE_PAGE_OFF_BUDDY +extern bool take_page_off_buddy(struct page *page, bool poison); +extern bool put_page_back_buddy(struct page *page, bool unpoison); #endif #if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT) diff --git a/mm/Kconfig b/mm/Kconfig index ffc3a2ba3a8c..341cf53898db 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -745,12 +745,16 @@ config DEFAULT_MMAP_MIN_ADDR config ARCH_SUPPORTS_MEMORY_FAILURE bool +config WANTS_TAKE_PAGE_OFF_BUDDY + bool + config MEMORY_FAILURE depends on MMU depends on ARCH_SUPPORTS_MEMORY_FAILURE bool "Enable recovery from hardware memory errors" select MEMORY_ISOLATION select RAS + select WANTS_TAKE_PAGE_OFF_BUDDY help Enables code to recover from some memory failures on systems with MCA recovery. This allows a system to continue running @@ -891,6 +895,7 @@ config CMA depends on MMU select MIGRATION select MEMORY_ISOLATION + select WANTS_TAKE_PAGE_OFF_BUDDY help This enables the Contiguous Memory Allocator which allows other subsystems to allocate big physically-contiguous blocks of memory. diff --git a/mm/cma.c b/mm/cma.c index 2881bab12b01..15663f95d77b 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -444,6 +444,34 @@ static void cma_debug_show_areas(struct cma *cma) static inline void cma_debug_show_areas(struct cma *cma) { } #endif +/* Called with the cma mutex held. */ +static int cma_alloc_pages_fastpath(struct cma *cma, unsigned long start, + unsigned long end) +{ + bool success = false; + unsigned long i, j; + + /* Avoid contention on the zone lock. */ + if (start - end != 1 << cma->order_per_bit) + return -EINVAL; + + for (i = start; i < end; i++) { + if (!is_free_buddy_page(pfn_to_page(i))) + break; + success = take_page_off_buddy(pfn_to_page(i), false); + if (!success) + break; + } + + if (success) + return 0; + + for (j = start; j < i; j++) + put_page_back_buddy(pfn_to_page(j), false); + + return -EBUSY; +} + /** * cma_alloc_range() - allocate pages in a specific range * @cma: Contiguous memory region for which the allocation is performed. @@ -493,7 +521,11 @@ int cma_alloc_range(struct cma *cma, unsigned long start, unsigned long count, for (i = 0; i < tries; i++) { mutex_lock(&cma_mutex); - err = alloc_contig_range(start, start + count, MIGRATE_CMA, gfp); + err = cma_alloc_pages_fastpath(cma, start, start + count); + if (err) { + err = alloc_contig_range(start, start + count, + MIGRATE_CMA, gfp); + } mutex_unlock(&cma_mutex); if (err != -EBUSY) @@ -529,7 +561,6 @@ int cma_alloc_range(struct cma *cma, unsigned long start, unsigned long count, return err; } - /** * cma_alloc() - allocate pages from contiguous area * @cma: Contiguous memory region for which the allocation is performed. @@ -589,8 +620,11 @@ struct page *cma_alloc(struct cma *cma, unsigned long count, pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit); mutex_lock(&cma_mutex); - ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA, - GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0)); + ret = cma_alloc_pages_fastpath(cma, pfn, pfn + count); + if (ret) { + ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA, + GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0)); + } mutex_unlock(&cma_mutex); if (ret == 0) { page = pfn_to_page(pfn); diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 4f9b61f4a668..b87b533a9871 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -157,7 +157,7 @@ static int __page_handle_poison(struct page *page) zone_pcp_disable(page_zone(page)); ret = dissolve_free_huge_page(page); if (!ret) - ret = take_page_off_buddy(page); + ret = take_page_off_buddy(page, true); zone_pcp_enable(page_zone(page)); return ret; @@ -1353,7 +1353,7 @@ static int page_action(struct page_state *ps, struct page *p, return action_result(pfn, ps->type, result); } -static inline bool PageHWPoisonTakenOff(struct page *page) +bool PageHWPoisonTakenOff(struct page *page) { return PageHWPoison(page) && page_private(page) == MAGIC_HWPOISON; } @@ -2247,7 +2247,7 @@ int memory_failure(unsigned long pfn, int flags) res = get_hwpoison_page(p, flags); if (!res) { if (is_free_buddy_page(p)) { - if (take_page_off_buddy(p)) { + if (take_page_off_buddy(p, true)) { page_ref_inc(p); res = MF_RECOVERED; } else { @@ -2578,7 +2578,7 @@ int unpoison_memory(unsigned long pfn) ret = folio_test_clear_hwpoison(folio) ? 0 : -EBUSY; } else if (ghp < 0) { if (ghp == -EHWPOISON) { - ret = put_page_back_buddy(p) ? 0 : -EBUSY; + ret = put_page_back_buddy(p, true) ? 0 : -EBUSY; } else { ret = ghp; unpoison_pr_info("Unpoison: failed to grab page %#lx\n", diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0fa34bcfb1af..502ee3eb8583 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6655,7 +6655,7 @@ bool is_free_buddy_page(struct page *page) } EXPORT_SYMBOL(is_free_buddy_page); -#ifdef CONFIG_MEMORY_FAILURE +#ifdef CONFIG_WANTS_TAKE_PAGE_OFF_BUDDY /* * Break down a higher-order page in sub-pages, and keep our target out of * buddy allocator. @@ -6687,9 +6687,9 @@ static void break_down_buddy_pages(struct zone *zone, struct page *page, } /* - * Take a page that will be marked as poisoned off the buddy allocator. + * Take a page off the buddy allocator, and optionally mark it as poisoned. */ -bool take_page_off_buddy(struct page *page) +bool take_page_off_buddy(struct page *page, bool poison) { struct zone *zone = page_zone(page); unsigned long pfn = page_to_pfn(page); @@ -6710,7 +6710,8 @@ bool take_page_off_buddy(struct page *page) del_page_from_free_list(page_head, zone, page_order); break_down_buddy_pages(zone, page_head, page, 0, page_order, migratetype); - SetPageHWPoisonTakenOff(page); + if (poison) + SetPageHWPoisonTakenOff(page); if (!is_migrate_isolate(migratetype)) __mod_zone_freepage_state(zone, -1, migratetype); ret = true; @@ -6724,9 +6725,10 @@ bool take_page_off_buddy(struct page *page) } /* - * Cancel takeoff done by take_page_off_buddy(). + * Cancel takeoff done by take_page_off_buddy(), and optionally unpoison the + * page. */ -bool put_page_back_buddy(struct page *page) +bool put_page_back_buddy(struct page *page, bool unpoison) { struct zone *zone = page_zone(page); unsigned long pfn = page_to_pfn(page); @@ -6736,17 +6738,18 @@ bool put_page_back_buddy(struct page *page) spin_lock_irqsave(&zone->lock, flags); if (put_page_testzero(page)) { - ClearPageHWPoisonTakenOff(page); + VM_WARN_ON_ONCE(PageHWPoisonTakenOff(page) && !unpoison); + if (unpoison) + ClearPageHWPoisonTakenOff(page); __free_one_page(page, pfn, zone, 0, migratetype, FPI_NONE); - if (TestClearPageHWPoison(page)) { + if (!unpoison || (unpoison && TestClearPageHWPoison(page))) ret = true; - } } spin_unlock_irqrestore(&zone->lock, flags); return ret; } -#endif +#endif /* CONFIG_WANTS_TAKE_PAGE_OFF_BUDDY */ #ifdef CONFIG_ZONE_DMA bool has_managed_dma(void)