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[99.151.34.247]) by smtp.gmail.com with ESMTPSA id f17-20020a170902ce9100b001e219142f18sm1189888plg.114.2024.04.05.08.03.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Apr 2024 08:03:16 -0700 (PDT) From: Ian Forbes To: dri-devel@lists.freedesktop.org Cc: bcm-kernel-feedback-list@broadcom.com, zack.rusin@broadcom.com, martin.krastev@broadcom.com, maaz.mombasawala@broadcom.com, Ian Forbes , stable@vger.kernel.org Subject: [PATCH v2] drm/vmwgfx: Don't memcmp equivalent pointers Date: Fri, 5 Apr 2024 10:02:45 -0500 Message-Id: <20240405150245.1797-1-ian.forbes@broadcom.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240328190716.27367-1-ian.forbes@broadcom.com> References: <20240328190716.27367-1-ian.forbes@broadcom.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" These pointers are frequently the same and memcmp does not compare the pointers before comparing their contents so this was wasting cycles comparing 16 KiB of memory which will always be equal. Fixes: bb6780aa5a1d ("drm/vmwgfx: Diff cursors when using cmds") Signed-off-by: Ian Forbes Cc: # v6.2+ --- v2: Fix code and commit message formatting. -- drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c index cd4925346ed4..ef0af10c4968 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c @@ -216,7 +216,7 @@ static bool vmw_du_cursor_plane_has_changed(struct vmw_plane_state *old_vps, new_image = vmw_du_cursor_plane_acquire_image(new_vps); changed = false; - if (old_image && new_image) + if (old_image && new_image && old_image != new_image) changed = memcmp(old_image, new_image, size) != 0; return changed;