On 06/25/2014 07:32 AM, Chuck Lever wrote: > Hi Shirley- > > On Jun 25, 2014, at 1:17 AM, Shirley Ma <shirley.ma@xxxxxxxxxx> wrote: > >> Would it be possible to delay rpcrdma_buffer_put() until LOCAL_INV request send completion? remove rpcrdma_buffer_put() from xprt_rdma_free(), add a call back after LOCAL_INV completed? > > That’s exactly what this patch does. The relevant part of > rpcrdma_buffer_put() is: > > list_add(&mw->mw_list, &buf->rb_mws); > > This is now wrapped with a reference count so that > rpcrdma_buffer_put() and the LOCAL_INV completion can run in any > order. The FRMR is added back to the list only after both of those > two have finished. What I was thinking is to run rpcrdma_buffer_put after LOCAL_INV completion without reference count. > Nothing in xprt_rdma_free() is allowed to sleep, so we can’t wait for > LOCAL_INV completion in there. > > The only alternative I can think of is having rpcrdma_buffer_get() check > fr_state as it removes FRMRs from the rb_mws list. Only if the FRMR is > marked FRMR_IS_INVALID, rpcrdma_buffer_get() will add it to the > rpcrdma_req. I thought about it too, an atomic operation would be better than a lock. > -- > Chuck Lever > chuck[dot]lever[at]oracle[dot]com > > > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
