In order to support ABD with large blocks the spl_kmem_alloc_warn
limit needs to be increased to 64K.
A 16M block requires that pointers be stored for 4096 4K-pages
on an x86_64 system. Each of these pointers is 8 bytes requiring
an allocation of 8*4096=32,768 bytes. The addition of a small
header to this structure pushes the allocation over the default
32K warning threshold.
In addition, fix a small bug where MAX was used instead of MIN
when setting the default. This ensures a reasonable limit is
still set on systems with page sizes larger then 4K.
Reviewed-by: David Quigley <david.quigley@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #571
* rate limited warning will be printed to the console for any kmem_alloc()
* which exceeds a reasonable threshold.
*
* rate limited warning will be printed to the console for any kmem_alloc()
* which exceeds a reasonable threshold.
*
- * The default warning threshold is set to eight pages but capped at 32K to
+ * The default warning threshold is set to sixteen pages but capped at 64K to
* accommodate systems using large pages. This value was selected to be small
* enough to ensure the largest allocations are quickly noticed and fixed.
* But large enough to avoid logging any warnings when a allocation size is
* accommodate systems using large pages. This value was selected to be small
* enough to ensure the largest allocations are quickly noticed and fixed.
* But large enough to avoid logging any warnings when a allocation size is
* allocations are quickly caught. These warnings may be disabled by setting
* the threshold to zero.
*/
* allocations are quickly caught. These warnings may be disabled by setting
* the threshold to zero.
*/
-unsigned int spl_kmem_alloc_warn = MAX(8 * PAGE_SIZE, 32 * 1024);
+unsigned int spl_kmem_alloc_warn = MIN(16 * PAGE_SIZE, 64 * 1024);
module_param(spl_kmem_alloc_warn, uint, 0644);
MODULE_PARM_DESC(spl_kmem_alloc_warn,
"Warning threshold in bytes for a kmem_alloc()");
module_param(spl_kmem_alloc_warn, uint, 0644);
MODULE_PARM_DESC(spl_kmem_alloc_warn,
"Warning threshold in bytes for a kmem_alloc()");