From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f72.google.com (mail-it0-f72.google.com [209.85.214.72]) by kanga.kvack.org (Postfix) with ESMTP id 855E26B0006 for ; Fri, 16 Feb 2018 13:10:07 -0500 (EST) Received: by mail-it0-f72.google.com with SMTP id k19so2305011ita.8 for ; Fri, 16 Feb 2018 10:10:07 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id d3sor862113itf.14.2018.02.16.10.10.06 for (Google Transport Security); Fri, 16 Feb 2018 10:10:06 -0800 (PST) Date: Fri, 16 Feb 2018 12:09:58 -0600 From: Dennis Zhou Subject: [PATCH v2 3/3] percpu: allow select gfp to be passed to underlying allocators Message-ID: <20180216180958.GB81034@localhost> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo , Christoph Lameter Cc: Daniel Borkmann , linux-mm@kvack.org, linux-kernel@vger.kernel.org The prior patch added support for passing gfp flags through to the underlying allocators. This patch allows users to pass along gfp flags (currently only __GFP_NORETRY and __GFP_NOWARN) to the underlying allocators. This should allow users to decide if they are ok with failing allocations recovering in a more graceful way. Additionally, gfp passing was done as additional flags in the previous patch. Instead, change this to caller passed semantics. GFP_KERNEL is also removed as the default flag. It continues to be used for internally caused underlying percpu allocations. V2: Removed gfp_percpu_mask in favor of doing it inline. Removed GFP_KERNEL as a default flag for __alloc_percpu_gfp. Signed-off-by: Dennis Zhou Suggested-by: Daniel Borkmann --- mm/percpu-km.c | 2 +- mm/percpu-vm.c | 4 ++-- mm/percpu.c | 16 +++++++--------- 3 files changed, 10 insertions(+), 12 deletions(-) diff --git a/mm/percpu-km.c b/mm/percpu-km.c index 0d88d7b..38de70a 100644 --- a/mm/percpu-km.c +++ b/mm/percpu-km.c @@ -56,7 +56,7 @@ static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp) if (!chunk) return NULL; - pages = alloc_pages(gfp | GFP_KERNEL, order_base_2(nr_pages)); + pages = alloc_pages(gfp, order_base_2(nr_pages)); if (!pages) { pcpu_free_chunk(chunk); return NULL; diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c index 0af71eb..d8078de 100644 --- a/mm/percpu-vm.c +++ b/mm/percpu-vm.c @@ -37,7 +37,7 @@ static struct page **pcpu_get_pages(void) lockdep_assert_held(&pcpu_alloc_mutex); if (!pages) - pages = pcpu_mem_zalloc(pages_size, 0); + pages = pcpu_mem_zalloc(pages_size, GFP_KERNEL); return pages; } @@ -86,7 +86,7 @@ static int pcpu_alloc_pages(struct pcpu_chunk *chunk, unsigned int cpu, tcpu; int i; - gfp |= GFP_KERNEL | __GFP_HIGHMEM; + gfp |= __GFP_HIGHMEM; for_each_possible_cpu(cpu) { for (i = page_start; i < page_end; i++) { diff --git a/mm/percpu.c b/mm/percpu.c index f97443d..fa3f854 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -454,9 +454,6 @@ static void pcpu_next_fit_region(struct pcpu_chunk *chunk, int alloc_bits, * This is to facilitate passing through whitelisted flags. The * returned memory is always zeroed. * - * CONTEXT: - * Does GFP_KERNEL allocation. - * * RETURNS: * Pointer to the allocated area on success, NULL on failure. */ @@ -466,10 +463,9 @@ static void *pcpu_mem_zalloc(size_t size, gfp_t gfp) return NULL; if (size <= PAGE_SIZE) - return kzalloc(size, gfp | GFP_KERNEL); + return kzalloc(size, gfp); else - return __vmalloc(size, gfp | GFP_KERNEL | __GFP_ZERO, - PAGE_KERNEL); + return __vmalloc(size, gfp | __GFP_ZERO, PAGE_KERNEL); } /** @@ -1344,6 +1340,8 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, gfp_t gfp) { + /* whitelisted flags that can be passed to the backing allocators */ + gfp_t pcpu_gfp = gfp & (GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN); bool is_atomic = (gfp & GFP_KERNEL) != GFP_KERNEL; bool do_warn = !(gfp & __GFP_NOWARN); static int warn_limit = 10; @@ -1426,7 +1424,7 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, } if (list_empty(&pcpu_slot[pcpu_nr_slots - 1])) { - chunk = pcpu_create_chunk(0); + chunk = pcpu_create_chunk(pcpu_gfp); if (!chunk) { err = "failed to allocate new chunk"; goto fail; @@ -1455,7 +1453,7 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, page_start, page_end) { WARN_ON(chunk->immutable); - ret = pcpu_populate_chunk(chunk, rs, re, 0); + ret = pcpu_populate_chunk(chunk, rs, re, pcpu_gfp); spin_lock_irqsave(&pcpu_lock, flags); if (ret) { @@ -1576,7 +1574,7 @@ void __percpu *__alloc_reserved_percpu(size_t size, size_t align) static void pcpu_balance_workfn(struct work_struct *work) { /* gfp flags passed to underlying allocators */ - const gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN; + const gfp_t gfp = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN; LIST_HEAD(to_free); struct list_head *free_head = &pcpu_slot[pcpu_nr_slots - 1]; struct pcpu_chunk *chunk, *next; -- 1.8.3.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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