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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 3B4B3C2BA1A for ; Tue, 7 Apr 2020 03:09:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EDECC20716 for ; Tue, 7 Apr 2020 03:09:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="tsS99p3g" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EDECC20716 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A2C398E0074; Mon, 6 Apr 2020 23:09:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9DB938E0062; Mon, 6 Apr 2020 23:09:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 919238E0074; Mon, 6 Apr 2020 23:09:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0028.hostedemail.com [216.40.44.28]) by kanga.kvack.org (Postfix) with ESMTP id 771518E0062 for ; Mon, 6 Apr 2020 23:09:56 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 447BE9096 for ; Tue, 7 Apr 2020 03:09:56 +0000 (UTC) X-FDA: 76679579592.16.ants92_90edd94a8383c X-HE-Tag: ants92_90edd94a8383c X-Filterd-Recvd-Size: 5649 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Apr 2020 03:09:55 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9E1F920801; Tue, 7 Apr 2020 03:09:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586228995; bh=ILk5O13i1ENlPRf5u0i9/HwXzzgiyORpjhsPjfUhW2M=; h=Date:From:To:Subject:In-Reply-To:From; b=tsS99p3gHtc7l19oHoZGJXs1kHznjI1tFr88eo4HmNHkig4kfNxD4Vsj6mzxjL+5I A6eeGZkcyYeiyMoJj+1izyB92LGD7pKzRcD2p+hs8BS+6EBNwHvfeicBQ/IPHiMmbp BKvUPtGzTgt2R2L5GMuzv7/tN0mkmL1lj0kU3sow= Date: Mon, 06 Apr 2020 20:09:54 -0700 From: Andrew Morton To: akpm@linux-foundation.org, colin.king@canonical.com, gregkh@linuxfoundation.org, keescook@chromium.org, khlebnikov@yandex-team.ru, linux-mm@kvack.org, linux@roeck-us.net, mm-commits@vger.kernel.org, peterz@infradead.org, pmladek@suse.com, rostedt@goodmis.org, sashal@kernel.org, sergey.senozhatsky@gmail.com, torvalds@linux-foundation.org Subject: [patch 110/166] lib/test_lockup.c: add parameters for locking generic vfs locks Message-ID: <20200407030954.oGSTJTCTN%akpm@linux-foundation.org> In-Reply-To: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: Konstantin Khlebnikov Subject: lib/test_lockup.c: add parameters for locking generic vfs locks file_path= defines file or directory to open lock_inode=Y set lock_rwsem_ptr to inode->i_rwsem lock_mapping=Y set lock_rwsem_ptr to mapping->i_mmap_rwsem lock_sb_umount=Y set lock_rwsem_ptr to sb->s_umount This gives safe and simple way to see how system reacts to contention of common vfs locks and how syscalls depend on them directly or indirectly. For example to block s_umount for 60 seconds: # modprobe test_lockup file_path=. lock_sb_umount time_secs=60 state=S This is useful for checking/testing scalability issues like this: https://lore.kernel.org/lkml/158497590858.7371.9311902565121473436.stgit@buzz/ Link: http://lkml.kernel.org/r/158498153964.5621.83061779039255681.stgit@buzz Signed-off-by: Konstantin Khlebnikov Cc: Colin Ian King Cc: Greg Kroah-Hartman Cc: Guenter Roeck Cc: Kees Cook Cc: Peter Zijlstra Cc: Petr Mladek Cc: Sasha Levin Cc: Sergey Senozhatsky Cc: Steven Rostedt Signed-off-by: Andrew Morton --- lib/test_lockup.c | 45 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) --- a/lib/test_lockup.c~lib-test_lockup-add-parameters-for-locking-generic-vfs-locks +++ a/lib/test_lockup.c @@ -14,6 +14,7 @@ #include #include #include +#include static unsigned int time_secs; module_param(time_secs, uint, 0600); @@ -140,6 +141,24 @@ static bool reallocate_pages; module_param(reallocate_pages, bool, 0400); MODULE_PARM_DESC(reallocate_pages, "free and allocate pages between iterations"); +struct file *test_file; +struct inode *test_inode; +static char test_file_path[256]; +module_param_string(file_path, test_file_path, sizeof(test_file_path), 0400); +MODULE_PARM_DESC(file_path, "file path to test"); + +static bool test_lock_inode; +module_param_named(lock_inode, test_lock_inode, bool, 0400); +MODULE_PARM_DESC(lock_inode, "lock file -> inode -> i_rwsem"); + +static bool test_lock_mapping; +module_param_named(lock_mapping, test_lock_mapping, bool, 0400); +MODULE_PARM_DESC(lock_mapping, "lock file -> mapping -> i_mmap_rwsem"); + +static bool test_lock_sb_umount; +module_param_named(lock_sb_umount, test_lock_sb_umount, bool, 0400); +MODULE_PARM_DESC(lock_sb_umount, "lock file -> sb -> s_umount"); + static atomic_t alloc_pages_failed = ATOMIC_INIT(0); static atomic64_t max_lock_wait = ATOMIC64_INIT(0); @@ -490,6 +509,29 @@ static int __init test_lockup_init(void) return -EINVAL; } + if (test_file_path[0]) { + test_file = filp_open(test_file_path, O_RDONLY, 0); + if (IS_ERR(test_file)) { + pr_err("cannot find file_path\n"); + return -EINVAL; + } + test_inode = file_inode(test_file); + } else if (test_lock_inode || + test_lock_mapping || + test_lock_sb_umount) { + pr_err("no file to lock\n"); + return -EINVAL; + } + + if (test_lock_inode && test_inode) + lock_rwsem_ptr = (unsigned long)&test_inode->i_rwsem; + + if (test_lock_mapping && test_file && test_file->f_mapping) + lock_rwsem_ptr = (unsigned long)&test_file->f_mapping->i_mmap_rwsem; + + if (test_lock_sb_umount && test_inode) + lock_rwsem_ptr = (unsigned long)&test_inode->i_sb->s_umount; + pr_notice("START pid=%d time=%u +%u ns cooldown=%u +%u ns iterations=%u state=%s %s%s%s%s%s%s%s%s%s%s%s\n", main_task->pid, time_secs, time_nsecs, cooldown_secs, cooldown_nsecs, iterations, state, @@ -542,6 +584,9 @@ static int __init test_lockup_init(void) pr_notice("FINISH in %llu ns\n", local_clock() - test_start); + if (test_file) + fput(test_file); + if (signal_pending(main_task)) return -EINTR; _