From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EAF6713AA27; Tue, 6 Feb 2024 12:09:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707221365; cv=none; b=QZZKC95rDKtGOE1lwJM7T9lyPshhPb+3hd/dt7WtCzQEo87AmLjL4Nft3kkZ2dP2G+dARdLNZ/tCdiUB7l2uOi0xc3uyNflkPqar8W9tilLloj3KLN58RYbhHqqSPm0Bd7nvTPimJFsTSHg9K5RyNrIb3c/VWA/BWmMz2zbfYPc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707221365; c=relaxed/simple; bh=KBGhBIbjsMRKtn4hdiJH0PuIBiRoV1R54hmlDTiI6ZI=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=hNqqS3brInlMhz58Js5IMEZcTU/ASKdW/2OwdP1C6kijrAg7otTpV2s7vw8373Sg7dhX1zdL8erdgFLvv5s1xlVvPEIT7miFZ3bsL+IioLvfJNyc0hI4ZatqI0fVZPho/RxzCXHQHYVawmBa2Md6xV9CMJYW3xvTMjPTckjx3uY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE464C4167E; Tue, 6 Feb 2024 12:09:24 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1rXKGv-00000006bLq-0naA; Tue, 06 Feb 2024 07:09:53 -0500 Message-ID: <20240206120953.046426517@rostedt.homelinux.com> User-Agent: quilt/0.67 Date: Tue, 06 Feb 2024 07:09:46 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Linus Torvalds , Greg Kroah-Hartman , Sasha Levin , Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Al Viro , Christian Brauner Subject: [v6.6][PATCH 41/57] eventfs: Shortcut eventfs_iterate() by skipping entries already read References: <20240206120905.570408983@rostedt.homelinux.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: "Steven Rostedt (Google)" As the ei->entries array is fixed for the duration of the eventfs_inode, it can be used to skip over already read entries in eventfs_iterate(). That is, if ctx->pos is greater than zero, there's no reason in doing the loop across the ei->entries array for the entries less than ctx->pos. Instead, start the lookup of the entries at the current ctx->pos. Link: https://lore.kernel.org/all/CAHk-=wiKwDUDv3+jCsv-uacDcHDVTYsXtBR9=6sGM5mqX+DhOg@mail.gmail.com/ Link: https://lore.kernel.org/linux-trace-kernel/20240104220048.494956957@goodmis.org Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Al Viro Cc: Christian Brauner Cc: Greg Kroah-Hartman Suggested-by: Linus Torvalds Signed-off-by: Steven Rostedt (Google) (cherry picked from commit 1de94b52d5e8d8b32f0252f14fad1f1edc2e71f1) --- fs/tracefs/event_inode.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index a1934e0eea3b..fdff53d5a1f8 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -746,21 +746,15 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx) if (!ei || !ei_dentry) goto out; - ret = 0; - /* * Need to create the dentries and inodes to have a consistent * inode number. */ - for (i = 0; i < ei->nr_entries; i++) { - void *cdata = ei->data; - - if (c > 0) { - c--; - continue; - } + ret = 0; - ctx->pos++; + /* Start at 'c' to jump over already read entries */ + for (i = c; i < ei->nr_entries; i++, ctx->pos++) { + void *cdata = ei->data; entry = &ei->entries[i]; name = entry->name; @@ -769,7 +763,7 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx) /* If ei->is_freed then just bail here, nothing more to do */ if (ei->is_freed) { mutex_unlock(&eventfs_mutex); - goto out_dec; + goto out; } r = entry->callback(name, &mode, &cdata, &fops); mutex_unlock(&eventfs_mutex); @@ -778,14 +772,17 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx) dentry = create_file_dentry(ei, i, ei_dentry, name, mode, cdata, fops); if (!dentry) - goto out_dec; + goto out; ino = dentry->d_inode->i_ino; dput(dentry); if (!dir_emit(ctx, name, strlen(name), ino, DT_REG)) - goto out_dec; + goto out; } + /* Subtract the skipped entries above */ + c -= min((unsigned int)c, (unsigned int)ei->nr_entries); + list_for_each_entry_srcu(ei_child, &ei->children, list, srcu_read_lock_held(&eventfs_srcu)) { -- 2.43.0