[Linux-ia64] RE: ia64 rwsem using atomic primitive

From: Chen, Kenneth W <kenneth.w.chen_at_intel.com>
Date: 2003-02-20 05:31:33
Here is a patch against 2.5.60.  It has one new function added __downgrade_write() for 2.5.

- Ken

 <<rwsem.2.5.60.patch>> 

>  -----Original Message-----
> From: 	Chen, Kenneth W  
> Sent:	Wednesday, February 19, 2003 10:30 AM
> To:	'linux-ia64@linuxia64.org'
> Subject:	ia64 rwsem using atomic primitive
> 
> I have converted rw semaphore from current generic spin_lock implementation to use architecture specific atomic operation on ia64.  This new scheme speeds up all the semaphore operations in the fast path with atomic instruction and fall back to a heavy function when there are read/write contention.  I've also taken some raw measurement how fast it improves.  The most significant gain comes from parallel reader lock acquire/release which has around 6.6X speed up with the new version.  Here is a patch against 2.4.20.
> 
>  << File: rwsem.2.4.20.patch >> 
> - Ken
> 



Received on Wed Feb 19 10:31:37 2003

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