From patchwork Sat Nov 10 01:38:07 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Edgecombe, Rick P" X-Patchwork-Id: 10676805 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 15B0814DB for ; Sat, 10 Nov 2018 01:36:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 023762E2AF for ; Sat, 10 Nov 2018 01:36:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E76BE2F050; Sat, 10 Nov 2018 01:36:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DBDCF2E2AF for ; Sat, 10 Nov 2018 01:36:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7C20C6B075F; Fri, 9 Nov 2018 20:36:32 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 74BCB6B0762; Fri, 9 Nov 2018 20:36:32 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 54D6C6B0763; Fri, 9 Nov 2018 20:36:32 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-pg1-f198.google.com (mail-pg1-f198.google.com [209.85.215.198]) by kanga.kvack.org (Postfix) with ESMTP id 086986B075F for ; Fri, 9 Nov 2018 20:36:32 -0500 (EST) Received: by mail-pg1-f198.google.com with SMTP id l2-v6so2357931pgp.22 for ; Fri, 09 Nov 2018 17:36:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=X+yXoRa7dyjtA1PEPWHn9Ke2eBTGNjHAfdIPgzyaQw4=; b=iYthp5u8c24UFvpZE48c+j4tm9ihJRT0T1ElaiPtfkaUwjETWjwiGM69bgPxF9NCYN m9eHQDX80r0UMxlDltXYRefQSr4FojCq4t0XnmT5meAtloqbhluqX/D9p+zesOr4oz+E P8DYJEVoaioIiGKbq5rqI1YADti5SWtDCGGmJPtnx/eaMfe1Yju3y8anJLzrLzB2CyYV 4jkGQagAHRiWN5qnRc2Vvj4urv6t7UekDqOg+OzoUlXulULDnP69L5VAkHVoNYRVr8cK eXSqXngtJoaemb418xQozyD5OlFbYlPNH9MAXW2ZFQvKlUdAmtA22Eu9TZOK9TONrJOX enxw== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of rick.p.edgecombe@intel.com designates 134.134.136.65 as permitted sender) smtp.mailfrom=rick.p.edgecombe@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Gm-Message-State: AGRZ1gKsK636yVWPY4V15YTUEpMV2teXXOaVGkqmQzIk09eD2f0mrvgy yK7DhYWFeOPM8Hz2ySm6MjPuh9w0GuRJuogpV3Zm9LJY9GQlox7gIAw399stZZcJPSJdmFcP46M cRyq3xyNWMUkI+UHtaTePCJ1n3/1NCGK+JdilXNHJ903U6wAAWlrU8asH70b/cX/dLA== X-Received: by 2002:a62:39d2:: with SMTP id u79-v6mr11419286pfj.116.1541813791641; Fri, 09 Nov 2018 17:36:31 -0800 (PST) X-Google-Smtp-Source: AJdET5eeX8G4cb5nZ0ypHaGq31lbSLXX/ddmZON1pxoLLlJUJUmYBVHLD3uKtvREp4R4afmGLIAE X-Received: by 2002:a62:39d2:: with SMTP id u79-v6mr11419215pfj.116.1541813790138; Fri, 09 Nov 2018 17:36:30 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1541813790; cv=none; d=google.com; s=arc-20160816; b=0bEBN7+vlkAnML3Qk+eDnTtLDyFDQ+W7Un6XhrsNCFVWF9AtEleh0NmDU8U4BwrhBQ F8fzw3+kPCqxOF/3XbFr2sc/9rIiq3vgCAfUDdBO83FkojiFT8jp+tefaUW+bKLlolwd gM1p95fDBz3Cf+vB2tkyL9kbVrZROdlKCWBX5pmSmia20kuJUFPX2OY59/wINHXJ1JkE hmVngNNznbsMhZhSlVmmTS2ugBla147rEDC37rXARUlrUpVcPhUwBuD3AeaW4ofrFxpG FyHo4mw8YJgqhCe01nb2t3+e08F8D6r/BxPueeKvxRaLTWsarfrKEEYlcIzW8SH5pwqt j7tQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from; bh=X+yXoRa7dyjtA1PEPWHn9Ke2eBTGNjHAfdIPgzyaQw4=; b=hYxgEcHDBGk3dkAWvKeRofwiRvXUWaY8UeZkv0pUYZ52pwhQgHeMgSm/y83Hv44D0A NVezX7ps5NGUx+Z2P1h8O9W5F8h5Ka18BnI18e5OVlU2oz4Q0vqWj+4PGS2fTRr6woIx WefFh1Bcv7cj0Ku6nm2WEcbtkAu1dmGtXtZsrwVg2Aej2lOMDhUls0sR2dVtdiFcPGlN VK2Dp6dKW8xyUS5Qf0NIwBxqeQbt4WEjjXl7BSJ4F0KMi2u7f6RyUxMfN3bJD7SnKaZx LmldsE0hJYOHUUDj8atmKEEcNrFmOT+2RpsAtD1B/zxN70CqlzNBO9Y6Kend5AOWoPRn rSxw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of rick.p.edgecombe@intel.com designates 134.134.136.65 as permitted sender) smtp.mailfrom=rick.p.edgecombe@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from mga03.intel.com (mga03.intel.com. [134.134.136.65]) by mx.google.com with ESMTPS id n32si8099080pgm.439.2018.11.09.17.36.29 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 09 Nov 2018 17:36:30 -0800 (PST) Received-SPF: pass (google.com: domain of rick.p.edgecombe@intel.com designates 134.134.136.65 as permitted sender) client-ip=134.134.136.65; Authentication-Results: mx.google.com; spf=pass (google.com: domain of rick.p.edgecombe@intel.com designates 134.134.136.65 as permitted sender) smtp.mailfrom=rick.p.edgecombe@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Nov 2018 17:36:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,485,1534834800"; d="scan'208";a="105025669" Received: from rpedgeco-desk5.jf.intel.com ([10.54.75.168]) by fmsmga004.fm.intel.com with ESMTP; 09 Nov 2018 17:36:28 -0800 From: Rick Edgecombe To: akpm@linux-foundation.org, willy@infradead.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com, daniel@iogearbox.net, jannh@google.com, keescook@chromium.org Cc: kristen@linux.intel.com, dave.hansen@intel.com, arjan@linux.intel.com, Rick Edgecombe Subject: [PATCH v9 4/4] Kselftest for module text allocation benchmarking Date: Fri, 9 Nov 2018 17:38:07 -0800 Message-Id: <20181110013807.24903-5-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181110013807.24903-1-rick.p.edgecombe@intel.com> References: <20181110013807.24903-1-rick.p.edgecombe@intel.com> MIME-Version: 1.0 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: X-Virus-Scanned: ClamAV using ClamSMTP This adds a test module in lib/, and a script in kselftest that does benchmarking on the allocation of memory in the module space. Performance here would have some small impact on kernel module insertions, BPF JIT insertions and kprobes. In the case of KASLR features for the module space, this module can be used to measure the allocation performance of different configurations. This module needs to be compiled into the kernel because module_alloc is not exported. With some modification to the code, as explained in the comments, it can be enabled to measure TLB flushes as well. There are two tests in the module. One allocates until failure in order to test module capacity and the other times allocating space in the module area. They both use module sizes that roughly approximate the distribution of in-tree X86_64 modules. You can control the number of modules used in the tests like this: echo m1000>/dev/mod_alloc_test Run the test for module capacity like: echo t1>/dev/mod_alloc_test The other test will measure the allocation time, and for CONFG_X86_64 and CONFIG_RANDOMIZE_BASE, also give data on how often the “backup area" is used. Run the test for allocation time and backup area usage like: echo t2>/dev/mod_alloc_test The output will be something like this: num all(ns) last(ns) 1000 1083 1099 Last module in backup count = 0 Total modules in backup = 0 >1 module in backup count = 0 To run a suite of allocation time tests for a collection of module numbers you can run: tools/testing/selftests/bpf/test_mod_alloc.sh Signed-off-by: Rick Edgecombe --- lib/Kconfig.debug | 9 + lib/Makefile | 1 + lib/test_mod_alloc.c | 375 ++++++++++++++++++ tools/testing/selftests/bpf/test_mod_alloc.sh | 29 ++ 4 files changed, 414 insertions(+) create mode 100644 lib/test_mod_alloc.c create mode 100755 tools/testing/selftests/bpf/test_mod_alloc.sh diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1af29b8224fd..b590b2bb312f 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1886,6 +1886,15 @@ config TEST_BPF If unsure, say N. +config TEST_MOD_ALLOC + bool "Tests for module allocator/vmalloc" + help + This builds the "test_mod_alloc" module that performs performance + tests on the module text section allocator. The module uses X86_64 + module text sizes for simulations. + + If unsure, say N. + config FIND_BIT_BENCHMARK tristate "Test find_bit functions" help diff --git a/lib/Makefile b/lib/Makefile index db06d1237898..c447e07931b0 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -60,6 +60,7 @@ UBSAN_SANITIZE_test_ubsan.o := y obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o obj-$(CONFIG_TEST_LKM) += test_module.o +obj-$(CONFIG_TEST_MOD_ALLOC) += test_mod_alloc.o obj-$(CONFIG_TEST_OVERFLOW) += test_overflow.o obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o obj-$(CONFIG_TEST_SORT) += test_sort.o diff --git a/lib/test_mod_alloc.c b/lib/test_mod_alloc.c new file mode 100644 index 000000000000..3a6fb7999df4 --- /dev/null +++ b/lib/test_mod_alloc.c @@ -0,0 +1,375 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * This module can be used to test allocation allocation time and randomness. + * + * To interact with this module, mount debugfs, for example: + * mount -t debugfs none /sys/kernel/debug/ + * + * Then write to the file: + * /sys/kernel/debug/mod_alloc_test + * + * There are two tests: + * Test 1: Allocate until failure + * Test 2: Run 1000 iterations of a test the simulates loading modules with + * x86_64 module sizes. + * + * Configure the number (ex:1000) of modules to use per test in the tests: + * echo m1000 > /sys/kernel/debug/mod_alloc_test + * + * To run test (ex: Test 2): + * echo t2 > /sys/kernel/debug/mod_alloc_test + * + * For test 1 it will print the results of each test. For test 2 it will print + * out statistics for example: + * New module count: 1000 + * Starting 10000 iterations of 1000 modules + * num all(ns) last(ns) + * 1000 1984 2112 + * Last module in backup count = 0 + * Total modules in backup = 188 + * >1 module in backup count = 7 + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct mod { int filesize; int coresize; int initsize; }; + +/* ==== Begin optional logging ==== */ +/* + * Note: In order to get an accurate count for the tlb flushes triggered in + * vmalloc, create a counter in vmalloc.c with this method signature and export + * it. Then replace the below with: + * + * extern unsigned long get_tlb_flushes_vmalloc(void); + */ +static unsigned long get_tlb_flushes_vmalloc(void) +{ + return 0; +} + +/* ==== End optional logging ==== */ + + +#define MAX_ALLOC_CNT 20000 +#define ITERS 1000 + +struct vm_alloc { + void *core; + unsigned long core_size; + void *init; +}; + +static struct vm_alloc *allocs_vm; +static long mod_cnt; +static DEFINE_MUTEX(test_mod_alloc_mutex); + +const static int core_hist[10] = {1, 5, 21, 46, 141, 245, 597, 2224, 1875, 0}; +const static int init_hist[10] = {0, 0, 0, 0, 10, 19, 70, 914, 3906, 236}; +const static int file_hist[10] = {6, 20, 55, 86, 286, 551, 918, 2024, 1028, + 181}; + +const static int bins[10] = {5000000, 2000000, 1000000, 500000, 200000, 100000, + 50000, 20000, 10000, 5000}; +/* + * Rough approximation of the X86_64 module size distribution. + */ +static int get_mod_rand_size(const int *hist) +{ + int area_under = get_random_int() % 5155; + int i; + int last_bin = bins[0] + 1; + int sum = 0; + + for (i = 0; i <= 9; i++) { + sum += hist[i]; + if (area_under <= sum) + return bins[i] + + (get_random_int() % (last_bin - bins[i])); + last_bin = bins[i]; + } + return 4096; +} + +static struct mod get_rand_module(void) +{ + struct mod ret; + + ret.coresize = get_mod_rand_size(core_hist); + ret.initsize = get_mod_rand_size(init_hist); + ret.filesize = get_mod_rand_size(file_hist); + return ret; +} + +static void do_test_alloc_fail(void) +{ + struct vm_alloc *cur_alloc; + struct mod cur_mod; + void *file; + int mod_n, free_mod_n; + unsigned long fail = 0; + int iter; + + for (iter = 0; iter < ITERS; iter++) { + pr_info("Running iteration: %d\n", iter); + memset(allocs_vm, 0, mod_cnt * sizeof(struct vm_alloc)); + vm_unmap_aliases(); + for (mod_n = 0; mod_n < mod_cnt; mod_n++) { + cur_mod = get_rand_module(); + cur_alloc = &allocs_vm[mod_n]; + + /* Allocate */ + file = vmalloc(cur_mod.filesize); + cur_alloc->core = module_alloc(cur_mod.coresize); + cur_alloc->init = module_alloc(cur_mod.initsize); + + /* Clean up everything except core */ + if (!cur_alloc->core || !cur_alloc->init) { + fail++; + vfree(file); + if (cur_alloc->init) { + module_memfree(cur_alloc->init); + vm_unmap_aliases(); + } + break; + } + module_memfree(cur_alloc->init); + vm_unmap_aliases(); + vfree(file); + } + + /* Clean up core sizes */ + for (free_mod_n = 0; free_mod_n < mod_n; free_mod_n++) { + cur_alloc = &allocs_vm[free_mod_n]; + if (cur_alloc->core) + module_memfree(cur_alloc->core); + } + } + pr_info("Failures(%ld modules): %lu\n", mod_cnt, fail); +} + +#ifdef CONFIG_RANDOMIZE_FINE_MODULE +static int is_in_backup(void *addr) +{ + return (unsigned long)addr >= MODULES_VADDR + MODULES_RAND_LEN; +} +#else +static int is_in_backup(void *addr) +{ + return 0; +} +#endif + +static void do_test_last_perf(void) +{ + struct vm_alloc *cur_alloc; + struct mod cur_mod; + void *file; + int mod_n, mon_n_free; + unsigned long fail = 0; + int iter; + ktime_t start, diff; + ktime_t total_last = 0; + ktime_t total_all = 0; + + /* + * The number of last core allocations for each iteration that were + * allocated in the backup area. + */ + int last_in_bk = 0; + + /* + * The total number of core allocations that were in the backup area for + * all iterations. + */ + int total_in_bk = 0; + + /* The number of iterations where the count was more than 1 */ + int cnt_more_than_1 = 0; + + /* + * The number of core allocations that were in the backup area for the + * current iteration. + */ + int cur_in_bk = 0; + + unsigned long before_tlbs; + unsigned long tlb_cnt_total; + unsigned long tlb_cur; + unsigned long total_tlbs = 0; + + pr_info("Starting %d iterations of %ld modules\n", ITERS, mod_cnt); + + for (iter = 0; iter < ITERS; iter++) { + vm_unmap_aliases(); + before_tlbs = get_tlb_flushes_vmalloc(); + memset(allocs_vm, 0, mod_cnt * sizeof(struct vm_alloc)); + tlb_cnt_total = 0; + cur_in_bk = 0; + for (mod_n = 0; mod_n < mod_cnt; mod_n++) { + /* allocate how the module allocator allocates */ + + cur_mod = get_rand_module(); + cur_alloc = &allocs_vm[mod_n]; + file = vmalloc(cur_mod.filesize); + + tlb_cur = get_tlb_flushes_vmalloc(); + + start = ktime_get(); + cur_alloc->core = module_alloc(cur_mod.coresize); + diff = ktime_get() - start; + + cur_alloc->init = module_alloc(cur_mod.initsize); + + /* Collect metrics */ + if (is_in_backup(cur_alloc->core)) { + cur_in_bk++; + if (mod_n == mod_cnt - 1) + last_in_bk++; + } + total_all += diff; + + if (mod_n == mod_cnt - 1) + total_last += diff; + + tlb_cnt_total += get_tlb_flushes_vmalloc() - tlb_cur; + + /* If there is a failure, quit. init/core freed later */ + if (!cur_alloc->core || !cur_alloc->init) { + fail++; + vfree(file); + break; + } + /* Init sections do not last long so free here */ + module_memfree(cur_alloc->init); + vm_unmap_aliases(); + cur_alloc->init = NULL; + vfree(file); + } + + /* Collect per iteration metrics */ + total_in_bk += cur_in_bk; + if (cur_in_bk > 1) + cnt_more_than_1++; + total_tlbs += get_tlb_flushes_vmalloc() - before_tlbs; + + /* Collect per iteration metrics */ + for (mon_n_free = 0; mon_n_free < mod_cnt; mon_n_free++) { + cur_alloc = &allocs_vm[mon_n_free]; + module_memfree(cur_alloc->init); + module_memfree(cur_alloc->core); + } + } + + if (fail) + pr_info("There was an alloc failure, results invalid!\n"); + + pr_info("num\t\tall(ns)\t\tlast(ns)"); + pr_info("%ld\t\t%llu\t\t%llu\n", mod_cnt, + div64_s64(total_all, ITERS * mod_cnt), + div64_s64(total_last, ITERS)); + + if (IS_ENABLED(CONFIG_RANDOMIZE_FINE_MODULE)) { + pr_info("Last module in backup count = %d\n", last_in_bk); + pr_info("Total modules in backup = %d\n", total_in_bk); + pr_info(">1 module in backup count = %d\n", cnt_more_than_1); + } + /* + * This will usually hide info when the instrumentation is not in place. + */ + if (tlb_cnt_total) + pr_info("TLB Flushes: %lu\n", tlb_cnt_total); +} + +static void do_test(int test) +{ + switch (test) { + case 1: + do_test_alloc_fail(); + break; + case 2: + do_test_last_perf(); + break; + default: + pr_info("Unknown test\n"); + } +} + +static ssize_t device_file_write(struct file *filp, const char __user *user_buf, + size_t count, loff_t *offp) +{ + char buf[100]; + long input_num; + + if (count >= sizeof(buf) - 1) { + pr_info("Command too long\n"); + return count; + } + + if (!mutex_trylock(&test_mod_alloc_mutex)) { + pr_info("test_mod_alloc busy\n"); + return count; + } + + if (copy_from_user(buf, user_buf, count)) + goto error; + + buf[count] = 0; + + if (kstrtol(buf+1, 10, &input_num)) + goto error; + + switch (buf[0]) { + case 'm': + if (input_num > 0 && input_num <= MAX_ALLOC_CNT) { + pr_info("New module count: %ld\n", input_num); + mod_cnt = input_num; + if (allocs_vm) + vfree(allocs_vm); + allocs_vm = vmalloc(sizeof(struct vm_alloc) * mod_cnt); + } else + pr_info("more than %d not supported\n", MAX_ALLOC_CNT); + break; + case 't': + if (!mod_cnt) { + pr_info("Set module count first\n"); + break; + } + + do_test(input_num); + break; + default: + pr_info("Unknown command\n"); + } + goto done; +error: + pr_info("Could not process input\n"); +done: + mutex_unlock(&test_mod_alloc_mutex); + return count; +} + +static const char *dv_name = "mod_alloc_test"; +const static struct file_operations test_mod_alloc_fops = { + .owner = THIS_MODULE, + .write = device_file_write, +}; + +static int __init mod_alloc_test_init(void) +{ + debugfs_create_file(dv_name, 0400, NULL, NULL, &test_mod_alloc_fops); + + return 0; +} + +MODULE_LICENSE("GPL"); + +module_init(mod_alloc_test_init); diff --git a/tools/testing/selftests/bpf/test_mod_alloc.sh b/tools/testing/selftests/bpf/test_mod_alloc.sh new file mode 100755 index 000000000000..e9aea570de78 --- /dev/null +++ b/tools/testing/selftests/bpf/test_mod_alloc.sh @@ -0,0 +1,29 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +UNMOUNT_DEBUG_FS=0 +if ! mount | grep -q debugfs; then + if mount -t debugfs none /sys/kernel/debug/; then + UNMOUNT_DEBUG_FS=1 + else + echo "Could not mount debug fs." + exit 1 + fi +fi + +if [ ! -e /sys/kernel/debug/mod_alloc_test ]; then + echo "Test module not found, did you build kernel with TEST_MOD_ALLOC?" + exit 1 +fi + +echo "Beginning module_alloc performance tests." + +for i in `seq 1000 1000 8000`; do + echo m$i>/sys/kernel/debug/mod_alloc_test + echo t2>/sys/kernel/debug/mod_alloc_test +done + +echo "Module_alloc performance tests ended." + +if [ $UNMOUNT_DEBUG_FS -eq 1 ]; then + umount /sys/kernel/debug/ +fi