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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF7DAEB64DD for ; Tue, 25 Jul 2023 23:06:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231421AbjGYXGY (ORCPT ); Tue, 25 Jul 2023 19:06:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231379AbjGYXGX (ORCPT ); Tue, 25 Jul 2023 19:06:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44F5D9C; Tue, 25 Jul 2023 16:06:22 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C928861932; Tue, 25 Jul 2023 23:06:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05956C433C8; Tue, 25 Jul 2023 23:06:19 +0000 (UTC) Date: Tue, 25 Jul 2023 19:06:17 -0400 From: Steven Rostedt To: Ajay Kaher Cc: shuah@kernel.org, mhiramat@kernel.org, chinglinyu@google.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-trace-kernel@vger.kernel.org, lkp@intel.com, namit@vmware.com, oe-lkp@lists.linux.dev, amakhalov@vmware.com, er.ajay.kaher@gmail.com, srivatsa@csail.mit.edu, tkundu@vmware.com, vsirnapalli@vmware.com Subject: Re: [PATCH v5 02/10] eventfs: Implement tracefs_inode_cache Message-ID: <20230725190617.14c85997@rorschach.local.home> In-Reply-To: <1690054625-31939-3-git-send-email-akaher@vmware.com> References: <1690054625-31939-1-git-send-email-akaher@vmware.com> <1690054625-31939-3-git-send-email-akaher@vmware.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org Some more nits. On Sun, 23 Jul 2023 01:06:57 +0530 Ajay Kaher wrote: > Create a kmem cache of tracefs_inodes. To be more efficient, as there are > lots of tracefs inodes, create its own cache. This also allows to see how > many tracefs inodes have been created. > > Add helper functions: > tracefs_alloc_inode() > tracefs_free_inode() > get_tracefs() > > Signed-off-by: Ajay Kaher > Co-developed-by: Steven Rostedt (VMware) > Signed-off-by: Steven Rostedt (VMware) > Tested-by: Ching-lin Yu > --- > fs/tracefs/inode.c | 39 +++++++++++++++++++++++++++++++++++++++ > fs/tracefs/internal.h | 19 +++++++++++++++++++ > 2 files changed, 58 insertions(+) > create mode 100644 fs/tracefs/internal.h > > diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c > index 57ac8aa4a724..2508944cc4d8 100644 > --- a/fs/tracefs/inode.c > +++ b/fs/tracefs/inode.c > @@ -21,13 +21,33 @@ > #include > #include > #include > +#include "internal.h" > > #define TRACEFS_DEFAULT_MODE 0700 > +static struct kmem_cache *tracefs_inode_cachep __ro_after_init; > > static struct vfsmount *tracefs_mount; > static int tracefs_mount_count; > static bool tracefs_registered; > > +static struct inode *tracefs_alloc_inode(struct super_block *sb) > +{ > + struct tracefs_inode *ti; > + > + ti = kmem_cache_alloc(tracefs_inode_cachep, GFP_KERNEL); > + if (!ti) > + return NULL; > + > + ti->flags = 0; > + > + return &ti->vfs_inode; > +} > + > +static void tracefs_free_inode(struct inode *inode) > +{ > + kmem_cache_free(tracefs_inode_cachep, get_tracefs(inode)); > +} > + > static ssize_t default_read_file(struct file *file, char __user *buf, > size_t count, loff_t *ppos) > { > @@ -346,6 +366,9 @@ static int tracefs_show_options(struct seq_file *m, struct dentry *root) > } > > static const struct super_operations tracefs_super_operations = { > + .alloc_inode = tracefs_alloc_inode, > + .free_inode = tracefs_free_inode, > + .drop_inode = generic_delete_inode, > .statfs = simple_statfs, > .remount_fs = tracefs_remount, > .show_options = tracefs_show_options, > @@ -628,10 +651,26 @@ bool tracefs_initialized(void) > return tracefs_registered; > } > > +static void init_once(void *foo) > +{ > + struct tracefs_inode *ti = (struct tracefs_inode *) foo; > + > + inode_init_once(&ti->vfs_inode); > +} > + > static int __init tracefs_init(void) > { > int retval; > > + tracefs_inode_cachep = kmem_cache_create("tracefs_inode_cache", > + sizeof(struct tracefs_inode), > + 0, (SLAB_RECLAIM_ACCOUNT| > + SLAB_MEM_SPREAD| > + SLAB_ACCOUNT), > + init_once); > + if (!tracefs_inode_cachep) > + return -ENOMEM; > + > retval = sysfs_create_mount_point(kernel_kobj, "tracing"); > if (retval) > return -EINVAL; > diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h > new file mode 100644 > index 000000000000..49b5e8949e1c > --- /dev/null > +++ b/fs/tracefs/internal.h > @@ -0,0 +1,19 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef _TRACEFS_INTERNAL_H > +#define _TRACEFS_INTERNAL_H > + > +enum { > + TRACEFS_EVENT_INODE = BIT(1), > +}; Let's not introduce the enum until it is used. -- Steve > + > +struct tracefs_inode { > + unsigned long flags; > + void *private; > + struct inode vfs_inode; > +}; > + > +static inline struct tracefs_inode *get_tracefs(const struct inode *inode) > +{ > + return container_of(inode, struct tracefs_inode, vfs_inode); > +} > +#endif /* _TRACEFS_INTERNAL_H */