Messages in this thread Patch in this message | | | Subject | [PATCH] block: reduce spin_lock critical region | From | Eduardo Silva <> | Date | Thu, 19 May 2011 22:43:09 -0400 |
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the critical region is originally composed by a conditional plus a memory copy, the memory copy routine don't need protection. Moving the memcpy() outside the conditional also help to fix the 16 compiler warning messages generated in __u8 sn[16] def.
Signed-off-by: Eduardo Silva <edsiper@gmail.com> --- drivers/block/cciss.c | 19 +++++++++---------- 1 files changed, 9 insertions(+), 10 deletions(-)
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c index 9bf1398..199b35e 100644 --- a/drivers/block/cciss.c +++ b/drivers/block/cciss.c @@ -621,20 +621,19 @@ static ssize_t dev_show_unique_id(struct device *dev, spin_lock_irqsave(&h->lock, flags); if (h->busy_configuring) ret = -EBUSY; - else - memcpy(sn, drv->serial_no, sizeof(sn)); spin_unlock_irqrestore(&h->lock, flags); if (ret) return ret; - else - return snprintf(buf, 16 * 2 + 2, - "%02X%02X%02X%02X%02X%02X%02X%02X" - "%02X%02X%02X%02X%02X%02X%02X%02X\n", - sn[0], sn[1], sn[2], sn[3], - sn[4], sn[5], sn[6], sn[7], - sn[8], sn[9], sn[10], sn[11], - sn[12], sn[13], sn[14], sn[15]); + + memcpy(sn, drv->serial_no, sizeof(sn)); + return snprintf(buf, 16 * 2 + 2, + "%02X%02X%02X%02X%02X%02X%02X%02X" + "%02X%02X%02X%02X%02X%02X%02X%02X\n", + sn[0], sn[1], sn[2], sn[3], + sn[4], sn[5], sn[6], sn[7], + sn[8], sn[9], sn[10], sn[11], + sn[12], sn[13], sn[14], sn[15]); } static DEVICE_ATTR(unique_id, S_IRUGO, dev_show_unique_id, NULL); -- 1.7.4.1
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