From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Sandeen Subject: Re: [PATCH] jbd2: Fix the wrong calculation of t_max_wait in update_t_max_wait. Date: Tue, 10 May 2011 16:52:56 -0500 Message-ID: <4DC9B3B8.2040505@redhat.com> References: <1305024499-8826-1-git-send-email-tm@tao.ma> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org, Jan Kara , "Theodore Ts'o" To: Tao Ma Return-path: Received: from mx1.redhat.com ([209.132.183.28]:8952 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751361Ab1EJVxE (ORCPT ); Tue, 10 May 2011 17:53:04 -0400 In-Reply-To: <1305024499-8826-1-git-send-email-tm@tao.ma> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 5/10/11 5:48 AM, Tao Ma wrote: > From: Tao Ma > > t_max_wait is added in commit 8e85fb3f to indicate how long we > were waiting for new transaction to start. In commit 6d0bf005, > it is moved to another function named update_t_max_wait to > avoid a build warning. But the wrong thing is that the original > 'ts' is initialized in the start of function start_this_handle > and we can calculate t_max_wait in the right way. while with > this change, ts is initialized within the function and t_max_wait > can never be calculated right. > > This patch moves the initialization of ts to the original beginning > of start_this_handle and pass it to function update_t_max_wait so > that it can be calculated right and the build warning is avoided also. > > Cc: Jan Kara > Cc: "Theodore Ts'o" > Signed-off-by: Tao Ma Makes sense. Reviewed-by: Eric Sandeen > --- > fs/jbd2/transaction.c | 10 +++++----- > 1 files changed, 5 insertions(+), 5 deletions(-) > > diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c > index 05fa77a..85a055e 100644 > --- a/fs/jbd2/transaction.c > +++ b/fs/jbd2/transaction.c > @@ -82,7 +82,7 @@ jbd2_get_transaction(journal_t *journal, transaction_t *transaction) > */ > > /* > - * Update transiaction's maximum wait time, if debugging is enabled. > + * Update transaction's maximum wait time, if debugging is enabled. > * > * In order for t_max_wait to be reliable, it must be protected by a > * lock. But doing so will mean that start_this_handle() can not be > @@ -91,11 +91,10 @@ jbd2_get_transaction(journal_t *journal, transaction_t *transaction) > * means that maximum wait time reported by the jbd2_run_stats > * tracepoint will always be zero. > */ > -static inline void update_t_max_wait(transaction_t *transaction) > +static inline void update_t_max_wait(transaction_t *transaction, > + unsigned long ts) > { > #ifdef CONFIG_JBD2_DEBUG > - unsigned long ts = jiffies; > - > if (jbd2_journal_enable_debug && > time_after(transaction->t_start, ts)) { > ts = jbd2_time_diff(ts, transaction->t_start); > @@ -121,6 +120,7 @@ static int start_this_handle(journal_t *journal, handle_t *handle, > tid_t tid; > int needed, need_to_start; > int nblocks = handle->h_buffer_credits; > + unsigned long ts = jiffies; > > if (nblocks > journal->j_max_transaction_buffers) { > printk(KERN_ERR "JBD: %s wants too many credits (%d > %d)\n", > @@ -271,7 +271,7 @@ repeat: > /* OK, account for the buffers that this operation expects to > * use and add the handle to the running transaction. > */ > - update_t_max_wait(transaction); > + update_t_max_wait(transaction, ts); > handle->h_transaction = transaction; > atomic_inc(&transaction->t_updates); > atomic_inc(&transaction->t_handle_count);