Messages in this thread | | | Date | Sat, 13 Nov 2010 14:35:51 +0800 | From | Américo Wang <> | Subject | Re: Kernel rwlock design, Multicore and IGMP |
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On Fri, Nov 12, 2010 at 07:06:47PM +0800, Cypher Wu wrote: >> >> Note, on Tile, it uses a little different algorithm. >> > >It seems that rwlock on x86 and tile have different behavior, x86 use >RW_LOCK_BIAS, when read_lock() it will test if the lock is 0, and if >so then the read_lock() have to 'spinning', otherwise it dec the lock; >when write_lock() tried it first check if lock is It seems that rwlock >on x86 and tile have different behavior, x86 use RW_LOCK_BIAS and if >so, set lock to 0 and continue, otherwise it will 'spinning'. >I'm not very familiar with x86 architecture, but the code seems like >working that way.
No, they should be the same, sorry I made a mistake in the above reply.
Although Tile uses shifts in implementation while x86 uses inc/dec, the idea is same, either writers use higher bits and readers use lower bits or vice-versa.
-- Live like a child, think like the god.
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