From patchwork Wed Mar 31 23:53:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zi Yan X-Patchwork-Id: 12176611 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC2B7C433B4 for ; Wed, 31 Mar 2021 23:54:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ABF9661059 for ; Wed, 31 Mar 2021 23:54:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229959AbhCaXxa (ORCPT ); Wed, 31 Mar 2021 19:53:30 -0400 Received: from new3-smtp.messagingengine.com ([66.111.4.229]:49047 "EHLO new3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229497AbhCaXxU (ORCPT ); Wed, 31 Mar 2021 19:53:20 -0400 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailnew.nyi.internal (Postfix) with ESMTP id 1CD065808BE; Wed, 31 Mar 2021 19:53:20 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Wed, 31 Mar 2021 19:53:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sent.com; h=from :to:cc:subject:date:message-id:in-reply-to:references:reply-to :mime-version:content-transfer-encoding; s=fm3; bh=aMTk12SYydQOR 4tVPSaMqQA7+l6NP8cZ1IKoESLTZ5c=; b=g40iLeBK22TFPo//FglIhNO8KC3d5 CZ71TU9Er896OAlZ7CS78CwqtytEBRyiW4vdRDHFQbX7oNEtabBSuMwMZ5JBlaVj H8TjJjpRLcxvStFx7/OnPJ7Er8awYyOqASZQkda0AOXOWMujdSdmoCrv2tbvYvdR jRLz8YWCrTxurIwn4SKYIisankV94UGfPxxzdklqiQaYtXoRKds6HpihV0x2/jPu 4wEUYTinEq0CaduiufHxNQ5bhGclkyjNqKoCMoWu2wMySCq0lKQ8evpyxos7jdNc /+7skB0FUqSe5+JBkWp7yhWPlycyGOmrk9q+wwM5X+G5CaiVCJezg0lCQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:reply-to:subject :to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm2; bh=aMTk12SYydQOR4tVPSaMqQA7+l6NP8cZ1IKoESLTZ5c=; b=qCZVd6hq niY4gsQRO4A202gSiCGXFBQVwidCw4jEWVzvLXcfeuzY6aK1btNKJUxgSbD99555 G8rC8fVTcM+mJV5mhDRbQrCWHDZk4DVs4UoCtQ7qjINvAPmwWa4f7P5s4bpe/afe QoM2SoYZu9aWmUSkNNi5akc8zdt7PNqKL45jCnsC27j6wxhvdVwD/P9lfdnDdFEy m4W+/pUsC0AOhIRlL6dTDPr39t1y9uOecddMxyOfgQFSdVQHBg77Lgv9Kw+h3R0a +uqWMIaU8sEwxkrQDEuEkrE92zJFTYJj5Dkf6OGMOxvG7mY8XnroPq44HDM8N7et SkkIwQCgzY/eBQ== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrudeifedgvdehucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhephffvufffkffojghfrhgggfestdhqredtredttdenucfhrhhomhepkghiucgj rghnuceoiihirdihrghnsehsvghnthdrtghomheqnecuggftrfgrthhtvghrnhepieejue dvueduuefhgefhheeiuedvtedvuefgieegveetueeiueehtdegudehfeelnecukfhppeeh gedrudeiiedrudehledrvdejnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpe hmrghilhhfrhhomhepiihirdihrghnsehsvghnthdrtghomh X-ME-Proxy: Received: from Threadripper.local (ec2-54-166-159-27.compute-1.amazonaws.com [54.166.159.27]) by mail.messagingengine.com (Postfix) with ESMTPA id C1D4024005B; Wed, 31 Mar 2021 19:53:18 -0400 (EDT) From: Zi Yan To: Andrew Morton , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, "Kirill A . Shutemov" , Shuah Khan , John Hubbard , Sandipan Das , David Hildenbrand , Yang Shi , Mika Penttila , David Rientjes , Matthew Wilcox , Zi Yan Subject: [PATCH v8 2/2] mm: huge_memory: debugfs for file-backed THP split. Date: Wed, 31 Mar 2021 19:53:09 -0400 Message-Id: <20210331235309.332292-2-zi.yan@sent.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210331235309.332292-1-zi.yan@sent.com> References: <20210331235309.332292-1-zi.yan@sent.com> Reply-To: Zi Yan MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Zi Yan Further extend /split_huge_pages to accept ",," for file-backed THP split tests since tmpfs may have file backed by THP that mapped nowhere. Update selftest program to test file-backed THP split too. Suggested-by: Kirill A. Shutemov Signed-off-by: Zi Yan Reviewed-by: Yang Shi --- mm/huge_memory.c | 90 ++++++++++++++++++- .../selftests/vm/split_huge_page_test.c | 82 +++++++++++++++-- 2 files changed, 166 insertions(+), 6 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1bcab247aea8..eb0f3aaf49f1 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3062,6 +3062,65 @@ static int split_huge_pages_pid(int pid, unsigned long vaddr_start, return ret; } +static int split_huge_pages_in_file(const char *file_path, pgoff_t off_start, + pgoff_t off_end) +{ + struct filename *file; + struct file *candidate; + struct address_space *mapping; + int ret = -EINVAL; + pgoff_t index; + int nr_pages = 1; + unsigned long total = 0, split = 0; + + file = getname_kernel(file_path); + if (IS_ERR(file)) + return ret; + + candidate = file_open_name(file, O_RDONLY, 0); + if (IS_ERR(candidate)) + goto out; + + pr_debug("split file-backed THPs in file: %s, page offset: [0x%lx - 0x%lx]\n", + file_path, off_start, off_end); + + mapping = candidate->f_mapping; + + for (index = off_start; index < off_end; index += nr_pages) { + struct page *fpage = pagecache_get_page(mapping, index, + FGP_ENTRY | FGP_HEAD, 0); + + nr_pages = 1; + if (xa_is_value(fpage) || !fpage) + continue; + + if (!is_transparent_hugepage(fpage)) + goto next; + + total++; + nr_pages = thp_nr_pages(fpage); + + if (!trylock_page(fpage)) + goto next; + + if (!split_huge_page(fpage)) + split++; + + unlock_page(fpage); +next: + put_page(fpage); + cond_resched(); + } + + filp_close(candidate, NULL); + ret = 0; + + pr_debug("%lu of %lu file-backed THP split\n", split, total); +out: + putname(file); + return ret; +} + #define MAX_INPUT_BUF_SZ 255 static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, @@ -3069,7 +3128,8 @@ static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, { static DEFINE_MUTEX(split_debug_mutex); ssize_t ret; - char input_buf[MAX_INPUT_BUF_SZ]; /* hold pid, start_vaddr, end_vaddr */ + /* hold pid, start_vaddr, end_vaddr or file_path, off_start, off_end */ + char input_buf[MAX_INPUT_BUF_SZ]; int pid; unsigned long vaddr_start, vaddr_end; @@ -3084,6 +3144,34 @@ static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, goto out; input_buf[MAX_INPUT_BUF_SZ - 1] = '\0'; + + if (input_buf[0] == '/') { + char *tok; + char *buf = input_buf; + char file_path[MAX_INPUT_BUF_SZ]; + pgoff_t off_start = 0, off_end = 0; + size_t input_len = strlen(input_buf); + + tok = strsep(&buf, ","); + if (tok) { + strncpy(file_path, tok, MAX_INPUT_BUF_SZ); + } else { + ret = -EINVAL; + goto out; + } + + ret = sscanf(buf, "0x%lx,0x%lx", &off_start, &off_end); + if (ret != 2) { + ret = -EINVAL; + goto out; + } + ret = split_huge_pages_in_file(file_path, off_start, off_end); + if (!ret) + ret = input_len; + + goto out; + } + ret = sscanf(input_buf, "%d,0x%lx,0x%lx", &pid, &vaddr_start, &vaddr_end); if (ret == 1 && pid == 1) { split_huge_pages_all(); diff --git a/tools/testing/selftests/vm/split_huge_page_test.c b/tools/testing/selftests/vm/split_huge_page_test.c index 2c0c18e60c57..1af16d2c2a0a 100644 --- a/tools/testing/selftests/vm/split_huge_page_test.c +++ b/tools/testing/selftests/vm/split_huge_page_test.c @@ -7,11 +7,13 @@ #define _GNU_SOURCE #include #include +#include #include #include #include #include #include +#include #include #include @@ -24,6 +26,9 @@ uint64_t pmd_pagesize; #define SMAP_PATH "/proc/self/smaps" #define INPUT_MAX 80 +#define PID_FMT "%d,0x%lx,0x%lx" +#define PATH_FMT "%s,0x%lx,0x%lx" + #define PFN_MASK ((1UL<<55)-1) #define KPF_THP (1UL<<22) @@ -87,13 +92,16 @@ static int write_file(const char *path, const char *buf, size_t buflen) return (unsigned int) numwritten; } -static void write_debugfs(int pid, uint64_t vaddr_start, uint64_t vaddr_end) +static void write_debugfs(const char *fmt, ...) { char input[INPUT_MAX]; int ret; + va_list argp; + + va_start(argp, fmt); + ret = vsnprintf(input, INPUT_MAX, fmt, argp); + va_end(argp); - ret = snprintf(input, INPUT_MAX, "%d,0x%lx,0x%lx", pid, vaddr_start, - vaddr_end); if (ret >= INPUT_MAX) { printf("%s: Debugfs input is too long\n", __func__); exit(EXIT_FAILURE); @@ -183,7 +191,8 @@ void split_pmd_thp(void) } /* split all THPs */ - write_debugfs(getpid(), (uint64_t)one_page, (uint64_t)one_page + len); + write_debugfs(PID_FMT, getpid(), (uint64_t)one_page, + (uint64_t)one_page + len); for (i = 0; i < len; i++) if (one_page[i] != (char)i) { @@ -274,7 +283,7 @@ void split_pte_mapped_thp(void) } /* split all remapped THPs */ - write_debugfs(getpid(), (uint64_t)pte_mapped, + write_debugfs(PID_FMT, getpid(), (uint64_t)pte_mapped, (uint64_t)pte_mapped + pagesize * 4); /* smap does not show THPs after mremap, use kpageflags instead */ @@ -300,6 +309,68 @@ void split_pte_mapped_thp(void) close(kpageflags_fd); } +void split_file_backed_thp(void) +{ + int status; + int fd; + ssize_t num_written; + char tmpfs_template[] = "/tmp/thp_split_XXXXXX"; + const char *tmpfs_loc = mkdtemp(tmpfs_template); + char testfile[INPUT_MAX]; + uint64_t pgoff_start = 0, pgoff_end = 1024; + + printf("Please enable pr_debug in split_huge_pages_in_file() if you need more info.\n"); + + status = mount("tmpfs", tmpfs_loc, "tmpfs", 0, "huge=always,size=4m"); + + if (status) { + printf("Unable to create a tmpfs for testing\n"); + exit(EXIT_FAILURE); + } + + status = snprintf(testfile, INPUT_MAX, "%s/thp_file", tmpfs_loc); + if (status >= INPUT_MAX) { + printf("Fail to create file-backed THP split testing file\n"); + goto cleanup; + } + + fd = open(testfile, O_CREAT|O_WRONLY); + if (fd == -1) { + perror("Cannot open testing file\n"); + goto cleanup; + } + + /* write something to the file, so a file-backed THP can be allocated */ + num_written = write(fd, tmpfs_loc, sizeof(tmpfs_loc)); + close(fd); + + if (num_written < 1) { + printf("Fail to write data to testing file\n"); + goto cleanup; + } + + /* split the file-backed THP */ + write_debugfs(PATH_FMT, testfile, pgoff_start, pgoff_end); + + status = unlink(testfile); + if (status) + perror("Cannot remove testing file\n"); + +cleanup: + status = umount(tmpfs_loc); + if (status) { + printf("Unable to umount %s\n", tmpfs_loc); + exit(EXIT_FAILURE); + } + status = rmdir(tmpfs_loc); + if (status) { + perror("cannot remove tmp dir"); + exit(EXIT_FAILURE); + } + + printf("file-backed THP split test done, please check dmesg for more information\n"); +} + int main(int argc, char **argv) { if (geteuid() != 0) { @@ -313,6 +384,7 @@ int main(int argc, char **argv) split_pmd_thp(); split_pte_mapped_thp(); + split_file_backed_thp(); return 0; }