From bb77a077232e78476d7bc39c080f9e6685cbfd3c Mon Sep 17 00:00:00 2001 From: Mike Marciniszyn Date: Mon, 7 May 2012 14:02:42 -0400 Subject: IB/qib: Optimize pio ack buffer allocation This patch optimizes pio buffer allocation in the kernel. For qib, kernel pio buffers are used for sending acks. The code to allocate the buffer would always start at 0 until it found a buffer. This means that an average of 64 comparisions were done on each allocate, since the busy bit won't be cleared until the bits are refreshed when buffers are exhausted. This patch adds two new fields in the devdata struct, last_pio and min_kernel_pio. last_pio is the last buffer that was allocated. min_kernel_pio is the lowest potential available buffer. min_kernel_pio is modifed as contexts are allocated and deallocted. Reviewed-by: Ramkrishna Vepa Signed-off-by: Mike Marciniszyn Signed-off-by: Roland Dreier --- drivers/infiniband/hw/qib/qib_iba7322.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/infiniband/hw/qib/qib_iba7322.c') diff --git a/drivers/infiniband/hw/qib/qib_iba7322.c b/drivers/infiniband/hw/qib/qib_iba7322.c index 060b9606446..e7b9ad34fe2 100644 --- a/drivers/infiniband/hw/qib/qib_iba7322.c +++ b/drivers/infiniband/hw/qib/qib_iba7322.c @@ -6379,6 +6379,7 @@ static int qib_init_7322_variables(struct qib_devdata *dd) dd->cspec->sdmabufcnt; dd->lastctxt_piobuf = dd->cspec->lastbuf_for_pio - sbufs; dd->cspec->lastbuf_for_pio--; /* range is <= , not < */ + dd->last_pio = dd->cspec->lastbuf_for_pio; dd->pbufsctxt = (dd->cfgctxts > dd->first_user_ctxt) ? dd->lastctxt_piobuf / (dd->cfgctxts - dd->first_user_ctxt) : 0; -- cgit v1.2.3-70-g09d2