Messages in this thread | | | Date | Thu, 03 Mar 2005 19:04:22 -0500 | From | Jeff Garzik <> | Subject | Re: [PATCH][16/26] IB/mthca: mem-free doorbell record writing |
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Roland Dreier wrote: > Add a mthca_write_db_rec() to wrap writing doorbell records. On > 64-bit archs, this is just a 64-bit write, while on 32-bit archs it > splits the write into two 32-bit writes with a memory barrier to make > sure the two halves of the record are written in the correct order.
> +static inline void mthca_write_db_rec(u32 val[2], u32 *db) > +{ > + db[0] = val[0]; > + wmb(); > + db[1] = val[1]; > +} > +
Are you concerned about ordering, or write-combining?
I am unaware of a situation where writes are re-ordered into a reversed, descending order for no apparent reason.
Jeff
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