Author: imp Date: Mon Jan 29 00:00:52 2018 New Revision: 328521 URL: https://svnweb.freebsd.org/changeset/base/328521
Log: Use atomic load and stores to ensure that the compiler doesn't optimize away these loops. Change boolean to int to match what atomic API supplies. Remove wmb() since the atomic_store_rel() on status.done ensure the prior writes to status. It also fixes the fact that there wasn't a rmb() before reading done. This should also be more efficient since wmb() is fairly heavy weight. Sponsored by: Netflix Reviewed by: kib@, jim harris Differential Revision: https://reviews.freebsd.org/D14053 Modified: head/sys/dev/nvme/nvme.c head/sys/dev/nvme/nvme_ctrlr.c head/sys/dev/nvme/nvme_private.h Modified: head/sys/dev/nvme/nvme.c ============================================================================== --- head/sys/dev/nvme/nvme.c Sun Jan 28 23:58:22 2018 (r328520) +++ head/sys/dev/nvme/nvme.c Mon Jan 29 00:00:52 2018 (r328521) @@ -469,6 +469,5 @@ nvme_completion_poll_cb(void *arg, const struct nvme_c * the request passed or failed. */ memcpy(&status->cpl, cpl, sizeof(*cpl)); - wmb(); - status->done = TRUE; + atomic_store_rel_int(&status->done, 1); } Modified: head/sys/dev/nvme/nvme_ctrlr.c ============================================================================== --- head/sys/dev/nvme/nvme_ctrlr.c Sun Jan 28 23:58:22 2018 (r328520) +++ head/sys/dev/nvme/nvme_ctrlr.c Mon Jan 29 00:00:52 2018 (r328521) @@ -404,10 +404,10 @@ nvme_ctrlr_identify(struct nvme_controller *ctrlr) { struct nvme_completion_poll_status status; - status.done = FALSE; + status.done = 0; nvme_ctrlr_cmd_identify_controller(ctrlr, &ctrlr->cdata, nvme_completion_poll_cb, &status); - while (status.done == FALSE) + while (!atomic_load_acq_int(&status.done)) pause("nvme", 1); if (nvme_completion_is_error(&status.cpl)) { nvme_printf(ctrlr, "nvme_identify_controller failed!\n"); @@ -431,10 +431,10 @@ nvme_ctrlr_set_num_qpairs(struct nvme_controller *ctrl struct nvme_completion_poll_status status; int cq_allocated, sq_allocated; - status.done = FALSE; + status.done = 0; nvme_ctrlr_cmd_set_num_queues(ctrlr, ctrlr->num_io_queues, nvme_completion_poll_cb, &status); - while (status.done == FALSE) + while (!atomic_load_acq_int(&status.done)) pause("nvme", 1); if (nvme_completion_is_error(&status.cpl)) { nvme_printf(ctrlr, "nvme_ctrlr_set_num_qpairs failed!\n"); @@ -470,20 +470,20 @@ nvme_ctrlr_create_qpairs(struct nvme_controller *ctrlr for (i = 0; i < ctrlr->num_io_queues; i++) { qpair = &ctrlr->ioq[i]; - status.done = FALSE; + status.done = 0; nvme_ctrlr_cmd_create_io_cq(ctrlr, qpair, qpair->vector, nvme_completion_poll_cb, &status); - while (status.done == FALSE) + while (!atomic_load_acq_int(&status.done)) pause("nvme", 1); if (nvme_completion_is_error(&status.cpl)) { nvme_printf(ctrlr, "nvme_create_io_cq failed!\n"); return (ENXIO); } - status.done = FALSE; + status.done = 0; nvme_ctrlr_cmd_create_io_sq(qpair->ctrlr, qpair, nvme_completion_poll_cb, &status); - while (status.done == FALSE) + while (!atomic_load_acq_int(&status.done)) pause("nvme", 1); if (nvme_completion_is_error(&status.cpl)) { nvme_printf(ctrlr, "nvme_create_io_sq failed!\n"); @@ -693,10 +693,10 @@ nvme_ctrlr_configure_aer(struct nvme_controller *ctrlr ctrlr->async_event_config.raw = 0xFF; ctrlr->async_event_config.bits.reserved = 0; - status.done = FALSE; + status.done = 0; nvme_ctrlr_cmd_get_feature(ctrlr, NVME_FEAT_TEMPERATURE_THRESHOLD, 0, NULL, 0, nvme_completion_poll_cb, &status); - while (status.done == FALSE) + while (!atomic_load_acq_int(&status.done)) pause("nvme", 1); if (nvme_completion_is_error(&status.cpl) || (status.cpl.cdw0 & 0xFFFF) == 0xFFFF || Modified: head/sys/dev/nvme/nvme_private.h ============================================================================== --- head/sys/dev/nvme/nvme_private.h Sun Jan 28 23:58:22 2018 (r328520) +++ head/sys/dev/nvme/nvme_private.h Mon Jan 29 00:00:52 2018 (r328521) @@ -128,7 +128,7 @@ extern int32_t nvme_retry_count; struct nvme_completion_poll_status { struct nvme_completion cpl; - boolean_t done; + int done; }; #define NVME_REQUEST_VADDR 1 _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
