From: Shawn Lin <shawn.lin@rock-chips.com>
To: Oleg Drokin <oleg.drokin@intel.com>,
Andreas Dilger <andreas.dilger@intel.com>,
lustre-devel@lists.lustre.org, devel@driverdev.osuosl.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org,
Shawn Lin <shawn.lin@rock-chips.com>
Subject: [PATCH] staging/lustre: avoid zero buf for the first time
Date: Mon, 22 Aug 2016 16:46:04 +0800 [thread overview]
Message-ID: <1471855564-15962-1-git-send-email-shawn.lin@rock-chips.com> (raw)
We only need to zero it when repeating in order to
avoid old garbage. Let's improve it by moving this
before we repeat the calculation to save some cpu
cycle.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
---
drivers/staging/lustre/lustre/obdclass/llog.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/lustre/lustre/obdclass/llog.c b/drivers/staging/lustre/lustre/obdclass/llog.c
index 1784ca0..923061f 100644
--- a/drivers/staging/lustre/lustre/obdclass/llog.c
+++ b/drivers/staging/lustre/lustre/obdclass/llog.c
@@ -248,8 +248,6 @@ repeat:
CDEBUG(D_OTHER, "index: %d last_index %d\n",
index, last_index);
- /* get the buf with our target record; avoid old garbage */
- memset(buf, 0, LLOG_CHUNK_SIZE);
last_offset = cur_offset;
rc = llog_next_block(lpi->lpi_env, loghandle, &saved_index,
index, &cur_offset, buf, LLOG_CHUNK_SIZE);
@@ -275,8 +273,11 @@ repeat:
if (rec->lrh_index == 0) {
/* probably another rec just got added? */
rc = 0;
- if (index <= loghandle->lgh_last_idx)
+ if (index <= loghandle->lgh_last_idx) {
+ /* avoid old garbage */
+ memset(buf, 0, LLOG_CHUNK_SIZE);
goto repeat;
+ }
goto out; /* no more records */
}
if (rec->lrh_len == 0 ||
--
2.3.7
next reply other threads:[~2016-08-22 8:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-22 8:46 Shawn Lin [this message]
2016-08-22 10:04 ` [PATCH] staging/lustre: avoid zero buf for the first time Greg Kroah-Hartman
2016-08-26 19:48 ` Oleg Drokin
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