From d3b9e8ad425cfd5b9116732e057f1b48e4d3bcb8 Mon Sep 17 00:00:00 2001 From: Max Gurtovoy Date: Mon, 5 Mar 2018 20:09:48 +0200 Subject: RDMA/core: Reduce poll batch for direct cq polling Fix warning limit for kernel stack consumption: drivers/infiniband/core/cq.c: In function 'ib_process_cq_direct': drivers/infiniband/core/cq.c:78:1: error: the frame size of 1032 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] Using smaller ib_wc array on the stack brings us comfortably below that limit again. Fixes: 246d8b184c10 ("IB/cq: Don't force IB_POLL_DIRECT poll context for ib_process_cq_direct") Reported-by: Arnd Bergmann Reviewed-by: Sergey Gorenko Signed-off-by: Max Gurtovoy Signed-off-by: Leon Romanovsky Reviewed-by: Bart Van Assche Acked-by: Arnd Bergmann Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/cq.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) (limited to 'drivers/infiniband/core/cq.c') diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c index bc79ca8215d7..af5ad6a56ae4 100644 --- a/drivers/infiniband/core/cq.c +++ b/drivers/infiniband/core/cq.c @@ -17,6 +17,7 @@ /* # of WCs to poll for with a single call to ib_poll_cq */ #define IB_POLL_BATCH 16 +#define IB_POLL_BATCH_DIRECT 8 /* # of WCs to iterate over before yielding */ #define IB_POLL_BUDGET_IRQ 256 @@ -25,18 +26,18 @@ #define IB_POLL_FLAGS \ (IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS) -static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *poll_wc) +static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *wcs, + int batch) { int i, n, completed = 0; - struct ib_wc *wcs = poll_wc ? : cq->wc; /* * budget might be (-1) if the caller does not * want to bound this call, thus we need unsigned * minimum here. */ - while ((n = ib_poll_cq(cq, min_t(u32, IB_POLL_BATCH, - budget - completed), wcs)) > 0) { + while ((n = ib_poll_cq(cq, min_t(u32, batch, + budget - completed), wcs)) > 0) { for (i = 0; i < n; i++) { struct ib_wc *wc = &wcs[i]; @@ -48,8 +49,7 @@ static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *poll_wc) completed += n; - if (n != IB_POLL_BATCH || - (budget != -1 && completed >= budget)) + if (n != batch || (budget != -1 && completed >= budget)) break; } @@ -72,9 +72,9 @@ static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *poll_wc) */ int ib_process_cq_direct(struct ib_cq *cq, int budget) { - struct ib_wc wcs[IB_POLL_BATCH]; + struct ib_wc wcs[IB_POLL_BATCH_DIRECT]; - return __ib_process_cq(cq, budget, wcs); + return __ib_process_cq(cq, budget, wcs, IB_POLL_BATCH_DIRECT); } EXPORT_SYMBOL(ib_process_cq_direct); @@ -88,7 +88,7 @@ static int ib_poll_handler(struct irq_poll *iop, int budget) struct ib_cq *cq = container_of(iop, struct ib_cq, iop); int completed; - completed = __ib_process_cq(cq, budget, NULL); + completed = __ib_process_cq(cq, budget, cq->wc, IB_POLL_BATCH); if (completed < budget) { irq_poll_complete(&cq->iop); if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0) @@ -108,7 +108,8 @@ static void ib_cq_poll_work(struct work_struct *work) struct ib_cq *cq = container_of(work, struct ib_cq, work); int completed; - completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE, NULL); + completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE, cq->wc, + IB_POLL_BATCH); if (completed >= IB_POLL_BUDGET_WORKQUEUE || ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0) queue_work(ib_comp_wq, &cq->work); -- cgit v1.2.3-59-g8ed1b