From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Blanchard Subject: [PATCH] ibmvscsi: Speed up kexec boot Date: Mon, 23 Dec 2013 18:28:16 +1100 Message-ID: <20131223182816.0e8985af@kryten> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from ozlabs.org ([203.10.76.45]:43337 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750730Ab3LWH2S (ORCPT ); Mon, 23 Dec 2013 02:28:18 -0500 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Brian King , Robert Jennings Cc: linux-scsi@vger.kernel.org During kexec boot we call ibmvscsi_release_crq_queue() to tear down the old CRQ from the previous kernel. ibmvscsi_release_crq_queue() does this by calling H_FREE_CRQ. The hypervisor breaks this work down so as limit the time spent in any one hcall, so we have to loop until complete. At the moment we delay 0.1 seconds between every H_FREE_CRQ call. I see us calling H_FREE_CRQ 60 times on my box which means we delayed a total of 6 seconds. This delay is overkill, we are free to handle all busy return codes from the hypervisor as we see fit. Cut the delay down to something more reasonable - 1 ms. This improves my boot time by 6 seconds. Fix the other places we have arbitrary 100 ms delays. Signed-off-by: Anton Blanchard --- diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c index fa76440..ed7b52e 100644 --- a/drivers/scsi/ibmvscsi/ibmvscsi.c +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c @@ -159,7 +159,7 @@ static void ibmvscsi_release_crq_queue(struct crq_queue *queue, tasklet_kill(&hostdata->srp_task); do { if (rc) - msleep(100); + msleep(1); rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address); } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc))); dma_unmap_single(hostdata->dev, @@ -292,7 +292,7 @@ static int ibmvscsi_reset_crq_queue(struct crq_queue *queue, /* Close the CRQ */ do { if (rc) - msleep(100); + msleep(1); rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address); } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc))); @@ -392,7 +392,7 @@ static int ibmvscsi_init_crq_queue(struct crq_queue *queue, rc = 0; do { if (rc) - msleep(100); + msleep(1); rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address); } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc))); reg_crq_failed: @@ -420,7 +420,7 @@ static int ibmvscsi_reenable_crq_queue(struct crq_queue *queue, /* Re-enable the CRQ */ do { if (rc) - msleep(100); + msleep(1); rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address); } while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));