AcoSail/kernel_optimize_test
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blktrace: remove the big kernel lock

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According to Jens, this code does not need the BKL at all,
it is sufficiently serialized by bd_mutex.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Arnd Bergmann 2010-09-17 20:39:22 +02:00
parent 0fc86c7bd9
commit 01b284f9b6
1 changed files with 3 additions and 11 deletions
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14
kernel/trace/blktrace.c
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@ -23,7 +23,6 @@
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/debugfs.h>
#include <linux/smp_lock.h>
#include <linux/time.h>
#include <linux/uaccess.h>
@ -639,7 +638,6 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
if (!q)
return -ENXIO;
lock_kernel();
mutex_lock(&bdev->bd_mutex);
switch (cmd) {
@ -667,7 +665,6 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
}
mutex_unlock(&bdev->bd_mutex);
unlock_kernel();
return ret;
}
@ -1652,10 +1649,9 @@ static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
struct block_device *bdev;
ssize_t ret = -ENXIO;
lock_kernel();
bdev = bdget(part_devt(p));
if (bdev == NULL)
goto out_unlock_kernel;
goto out;
q = blk_trace_get_queue(bdev);
if (q == NULL)
@ -1683,8 +1679,7 @@ static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
mutex_unlock(&bdev->bd_mutex);
out_bdput:
bdput(bdev);
out_unlock_kernel:
unlock_kernel();
out:
return ret;
}
@ -1714,11 +1709,10 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
ret = -ENXIO;
lock_kernel();
p = dev_to_part(dev);
bdev = bdget(part_devt(p));
if (bdev == NULL)
goto out_unlock_kernel;
goto out;
q = blk_trace_get_queue(bdev);
if (q == NULL)
@ -1753,8 +1747,6 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
mutex_unlock(&bdev->bd_mutex);
out_bdput:
bdput(bdev);
out_unlock_kernel:
unlock_kernel();
out:
return ret ? ret : count;
}