From patchwork Wed Aug 17 10:14:11 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: akash.goel@intel.com X-Patchwork-Id: 9285479 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 10D506086A for ; Wed, 17 Aug 2016 10:01:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0089228895 for ; Wed, 17 Aug 2016 10:01:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E9DBB288A9; Wed, 17 Aug 2016 10:01:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 1CC7128895 for ; Wed, 17 Aug 2016 10:01:04 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 095CD6E7E0; Wed, 17 Aug 2016 10:01:03 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTP id EF80F6E7E0 for ; Wed, 17 Aug 2016 10:00:56 +0000 (UTC) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga101.fm.intel.com with ESMTP; 17 Aug 2016 03:00:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,529,1464678000"; d="scan'208";a="749856233" Received: from akashgoe-desktop.iind.intel.com ([10.223.82.36]) by FMSMGA003.fm.intel.com with ESMTP; 17 Aug 2016 03:00:55 -0700 From: akash.goel@intel.com To: intel-gfx@lists.freedesktop.org Date: Wed, 17 Aug 2016 15:44:11 +0530 Message-Id: <1471428859-10339-12-git-send-email-akash.goel@intel.com> X-Mailer: git-send-email 1.9.2 In-Reply-To: <1471428859-10339-1-git-send-email-akash.goel@intel.com> References: <1471428859-10339-1-git-send-email-akash.goel@intel.com> Cc: Akash Goel Subject: [Intel-gfx] [PATCH 11/19] drm/i915: Optimization to reduce the sampling time of GuC log buffer X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP From: Akash Goel GuC firmware sends an interrupt to flush the log buffer when it becomes half full, so Driver doesn't really need to sample the complete buffer and can just copy only the newly written data by GuC into the local buffer, i.e. as per the read & write pointer values. Moreover the flush interrupt would generally come for one type of log buffer, when it becomes half full, so at that time the other 2 types of log buffer would comparatively have much lesser unread data in them. In case of overflow reported by GuC, Driver do need to copy the entire buffer as the whole buffer would contain the unread data. v2: Rebase. v3: Fix the blooper of doing the copy twice. (Tvrtko) v4: Add curlies for 'else' case also, matching the 'if'. (Tvrtko) Signed-off-by: Akash Goel Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_guc_submission.c | 40 +++++++++++++++++++++++++----- 1 file changed, 34 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index 8b53a22..e46828b 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -1011,8 +1011,9 @@ static void guc_read_update_log_buffer(struct intel_guc *guc) struct guc_log_buffer_state *log_buffer_state, *log_buffer_snapshot_state; struct guc_log_buffer_state log_buffer_state_local; void *src_data_ptr, *dst_data_ptr; - unsigned int buffer_size; + unsigned int buffer_size, read_offset, write_offset, bytes_to_copy; enum guc_log_buffer_type type; + bool new_overflow; if (WARN_ON(!guc->log.buf_addr)) return; @@ -1035,11 +1036,14 @@ static void guc_read_update_log_buffer(struct intel_guc *guc) memcpy(&log_buffer_state_local, log_buffer_state, sizeof(struct guc_log_buffer_state)); buffer_size = guc_get_log_buffer_size(type); + read_offset = log_buffer_state_local.read_ptr; + write_offset = log_buffer_state_local.sampled_write_ptr; /* Bookkeeping stuff */ guc->log.flush_count[type] += log_buffer_state_local.flush_to_file; if (log_buffer_state_local.buffer_full_cnt != guc->log.prev_overflow_count[type]) { + new_overflow = 1; guc->log.total_overflow_count[type] += (log_buffer_state_local.buffer_full_cnt - guc->log.prev_overflow_count[type]); @@ -1053,6 +1057,8 @@ static void guc_read_update_log_buffer(struct intel_guc *guc) guc->log.prev_overflow_count[type] = log_buffer_state_local.buffer_full_cnt; DRM_ERROR_RATELIMITED("GuC log buffer overflow\n"); + } else { + new_overflow = 0; } if (log_buffer_snapshot_state) { @@ -1065,13 +1071,36 @@ static void guc_read_update_log_buffer(struct intel_guc *guc) * for consistency set the write pointer value to same * value of sampled_write_ptr in the snapshot buffer. */ - log_buffer_snapshot_state->write_ptr = - log_buffer_snapshot_state->sampled_write_ptr; + log_buffer_snapshot_state->write_ptr = write_offset; log_buffer_snapshot_state++; /* Now copy the actual logs. */ - memcpy(dst_data_ptr, src_data_ptr, buffer_size); + if (unlikely(new_overflow)) { + /* copy the whole buffer in case of overflow */ + read_offset = 0; + write_offset = buffer_size; + } else if (unlikely((read_offset > buffer_size) || + (write_offset > buffer_size))) { + DRM_ERROR("invalid log buffer state\n"); + /* copy whole buffer as offsets are unreliable */ + read_offset = 0; + write_offset = buffer_size; + } + + /* Just copy the newly written data */ + if (read_offset <= write_offset) { + bytes_to_copy = write_offset - read_offset; + memcpy(dst_data_ptr + read_offset, + src_data_ptr + read_offset, bytes_to_copy); + } else { + bytes_to_copy = buffer_size - read_offset; + memcpy(dst_data_ptr + read_offset, + src_data_ptr + read_offset, bytes_to_copy); + + bytes_to_copy = write_offset; + memcpy(dst_data_ptr, src_data_ptr, bytes_to_copy); + } src_data_ptr += buffer_size; dst_data_ptr += buffer_size; @@ -1080,8 +1109,7 @@ static void guc_read_update_log_buffer(struct intel_guc *guc) /* FIXME: invalidate/flush for log buffer needed */ /* Update the read pointer in the shared log buffer */ - log_buffer_state->read_ptr = - log_buffer_state_local.sampled_write_ptr; + log_buffer_state->read_ptr = write_offset; /* Clear the 'flush to file' flag */ log_buffer_state->flush_to_file = 0;