From mboxrd@z Thu Jan 1 00:00:00 1970 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=-12.8 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 autolearn=ham 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 3FBEEC433C1 for ; Sat, 20 Mar 2021 00:00:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9F47561950 for ; Sat, 20 Mar 2021 00:00:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9F47561950 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 06DC06B0083; Fri, 19 Mar 2021 20:00:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 01E376B0085; Fri, 19 Mar 2021 20:00:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DD9536B0088; Fri, 19 Mar 2021 20:00:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0026.hostedemail.com [216.40.44.26]) by kanga.kvack.org (Postfix) with ESMTP id BE6176B0083 for ; Fri, 19 Mar 2021 20:00:13 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 6DD9612EF for ; Sat, 20 Mar 2021 00:00:13 +0000 (UTC) X-FDA: 77938295106.15.C79E122 Received: from mail-ej1-f46.google.com (mail-ej1-f46.google.com [209.85.218.46]) by imf26.hostedemail.com (Postfix) with ESMTP id E95EB4080F44 for ; Sat, 20 Mar 2021 00:00:12 +0000 (UTC) Received: by mail-ej1-f46.google.com with SMTP id kt15so2832268ejb.12 for ; Fri, 19 Mar 2021 17:00:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=zTafU10YQYaIjshNkbpLe+B6v0K54rZkacG7T/BzgeA=; b=VkvFmmMJsSp7M5acOUl+XJW8UZaR058eC0KPor1xSnVbiiNh/7Zahi0TsMrJoUp0PR BaCGBNrE/KWmk5kOaLPeOVXyGzC5Dd7O1PHmNkcBDZT778gdYjfY+87DzrefSky3vbBA RUTHkEMB92cDAbbRIvmjAa/toH8/DaWosqtRkz/02e6QC4Z6G6wIjFR2XhcNVam7kNq6 V1tsZei3RzpMs4K8NZMEJvbyaqiUUMGShReinfHl3hj5O9GpxJpdZFJGppRpT6pWdRK0 NGyRrl+02lHlth/7UixVMAdvltVRHfBiSUzrm1GDVAsgJ1R7BwHPbh/I369HbdSOdSTE Zzzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=zTafU10YQYaIjshNkbpLe+B6v0K54rZkacG7T/BzgeA=; b=MQwgtc41QWKVicMTxhEsePC5oLZXaSwl2yN4mKhUDH2QUR1LPh0xFde2KV7u20IsbM SyZXOpAHK5SBISfeWur1Q1qartMKzOdxuHTG2VKyKt7hkX4f2481FM3D17yKF0YZ/I+D CXuBGUDASpi90f1uJg9F+1p4WpaBrir/7AN3SVRS0aEyAErOHy3WvDimLnljScZwvu+T oTLVGKU95dTvJEyPZeGyM5AodZc5scvtgZmI1wRRYwUqQKKRztcvAjuRsLJxHIOQXCOL ZkNKCVCe1IHVYvzl13S9pj0RxbjbCjPj52mVNqVC4GwNvGkJ+t4o6No4gDViQTTdwKPV fExQ== X-Gm-Message-State: AOAM532ItSb3w9NIyxRrlIjt5EEUNRopkm1dmCkHDQCzDJD89dud3/14 t1bjNjXLcn2+PHq7EaeY9Y6hdDP5k6/jgxHJuWQ= X-Google-Smtp-Source: ABdhPJzF7qYEup/avluFhIIVJZLCv0GDiLAOHPc2MhqDxRgx52OkzuyIwGA7dSBXmrAlSsV9WWGjeAGxX3RuwZ0ZkdA= X-Received: by 2002:a17:906:789:: with SMTP id l9mr7129296ejc.161.1616198409563; Fri, 19 Mar 2021 17:00:09 -0700 (PDT) MIME-Version: 1.0 References: <20210319005219.13595-1-zi.yan@sent.com> <20210319005219.13595-2-zi.yan@sent.com> In-Reply-To: <20210319005219.13595-2-zi.yan@sent.com> From: Yang Shi Date: Fri, 19 Mar 2021 16:59:57 -0700 Message-ID: Subject: Re: [PATCH v5 2/2] mm: huge_memory: debugfs for file-backed THP split. To: Zi Yan Cc: Linux MM , Linux Kernel Mailing List , linux-kselftest@vger.kernel.org, "Kirill A . Shutemov" , Andrew Morton , Shuah Khan , John Hubbard , Sandipan Das , David Hildenbrand , Mika Penttila Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: 5uma7nqq9c4bkrjadeeoft3me35amdfk X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: E95EB4080F44 Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf26; identity=mailfrom; envelope-from=""; helo=mail-ej1-f46.google.com; client-ip=209.85.218.46 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616198412-362955 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 Thu, Mar 18, 2021 at 5:52 PM Zi Yan wrote: > > 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 > --- > mm/huge_memory.c | 97 ++++++++++++++++++- > .../selftests/vm/split_huge_page_test.c | 79 ++++++++++++++- > 2 files changed, 168 insertions(+), 8 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 9bf9bc489228..6d6537cc8c56 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -3049,12 +3049,74 @@ 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 off_cur; > + 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_info("split file-backed THPs in file: %s, offset: [0x%lx - 0x%lx]\n", > + file_path, off_start, off_end); > + > + mapping = candidate->f_mapping; > + > + for (off_cur = off_start; off_cur < off_end;) { > + struct page *fpage = pagecache_get_page(mapping, off_cur, > + FGP_ENTRY | FGP_HEAD, 0); > + > + if (xa_is_value(fpage) || !fpage) { > + off_cur += PAGE_SIZE; > + continue; > + } > + > + if (!is_transparent_hugepage(fpage)) { > + off_cur += PAGE_SIZE; > + goto next; > + } > + total++; > + off_cur = fpage->index + thp_size(fpage); > + > + if (!trylock_page(fpage)) > + goto next; > + > + if (!split_huge_page(fpage)) > + split++; > + > + unlock_page(fpage); > +next: > + put_page(fpage); > + } > + > + filp_close(candidate, NULL); > + ret = 0; > + > + pr_info("%lu of %lu file-backed THP split\n", split, total); > +out: > + putname(file); > + return ret; > +} > + > +#define MAX_INPUT_BUF_SZ 255 As I mentioned in the first patch, you may move this to the first patch. I don't think it is necessary to add some code then remove it right in the following patch. Otherwise the patch looks good to me. Reviewed-by: Yang Shi > + > static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, > size_t count, loff_t *ppops) > { > static DEFINE_MUTEX(split_debug_mutex); > ssize_t ret; > - char input_buf[80]; /* 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; > > @@ -3064,11 +3126,40 @@ static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, > > ret = -EFAULT; > > - memset(input_buf, 0, 80); > + memset(input_buf, 0, MAX_INPUT_BUF_SZ); > if (copy_from_user(input_buf, buf, min_t(size_t, count, 80))) > goto out; > > - input_buf[79] = '\0'; > + 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) { > + pr_info("ret: %ld\n", ret); > + 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..ebdf2d738978 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 +309,65 @@ 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]; > + > + 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, 0, 1024); > + > + 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 +381,7 @@ int main(int argc, char **argv) > > split_pmd_thp(); > split_pte_mapped_thp(); > + split_file_backed_thp(); > > return 0; > } > -- > 2.30.2 >