Re: Perfromance issues
* Steve Grubb (sgrubb(a)redhat.com) wrote:
+++ linux-2.6.9~pre75/fs/attr.c
@@ -68,6 +69,8 @@
unsigned int ia_valid = attr->ia_valid;
int error = 0;
+ audit_notify_watch(inode, MAY_WRITE);
+
if (ia_valid & ATTR_SIZE) {
if (attr->ia_size != i_size_read(inode)) {
error = vmtruncate(inode, attr->ia_size);
+void audit_notify_watch(struct inode *inode, int mask)
+{
+ struct audit_inode_data *data;
+
+ if (likely(!audit_enabled))
+ return;
This means that the variables have to be pushed onto the stack, a call
performed, the enabled test, do a return instruction, and then pop the stack.
Its probably faster to do:
+ if (unlikely(audit_enabled))
+ audit_notify_watch(inode, MAY_WRITE);
+
Any micro optimisation needs to be benchmarked to show whether it's really
useful (I'd expect this one to be in the noise even though assembly
inspection should show improvement). IMO, a better choice would be
a static inline stub to keep from cluttering call sites. Smth. like:
static inline void audit_notify_watch(struct inode *inode, int mask)
{
if (likely(!audit_enabled))
return;
__audit_notify_watch(inode, mask);
}
thanks,
-chris