From patchwork Wed Feb 23 19:38:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 545408 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71B3EC433FE for ; Wed, 23 Feb 2022 19:38:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244471AbiBWTih (ORCPT ); Wed, 23 Feb 2022 14:38:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233923AbiBWTig (ORCPT ); Wed, 23 Feb 2022 14:38:36 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFFB348E6A for ; Wed, 23 Feb 2022 11:38:08 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 803371F37E; Wed, 23 Feb 2022 19:38:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1645645087; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=s5ZN7uI6UG6Di2iSINpGQFR90gjSNoFjkDK2XKHJmb8=; b=PCa6oGDrQ1n2qcRHF5a73W6x6YgnrbQsuD32eUczTD2snckw0qWUf22KsXT0Pv7dQ+Jhaa CE7FslEwt4wDJywN4UCFyNds61jSLj7sjcsSrnCX+ECjRe0izJewbRoHLsrspAW1pupja9 5XnM9sJTjDmPeWP8YwYmK2Tl6/D5oKo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1645645087; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=s5ZN7uI6UG6Di2iSINpGQFR90gjSNoFjkDK2XKHJmb8=; b=Jx64EzN+aniD/z/Ga2FsNuAbxSPpCLCdhHw+MhW2Vu5gLLuGu9Va55v559ikUYFAK9dQ/t hSlW0/dUP53WjDCw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 47FD513DAC; Wed, 23 Feb 2022 19:38:07 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id WOaNEB+NFmKfUgAAMHmgww (envelope-from ); Wed, 23 Feb 2022 19:38:07 +0000 From: Thomas Zimmermann To: daniel@ffwll.ch, deller@gmx.de, javierm@redhat.com, geert@linux-m68k.org, sam@ravnborg.org, kraxel@redhat.com, ppaalanen@gmail.com Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, Thomas Zimmermann Subject: [PATCH v3 1/5] fbdev: Improve performance of sys_fillrect() Date: Wed, 23 Feb 2022 20:38:00 +0100 Message-Id: <20220223193804.18636-2-tzimmermann@suse.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220223193804.18636-1-tzimmermann@suse.de> References: <20220223193804.18636-1-tzimmermann@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Improve the performance of sys_fillrect() by using word-aligned 32/64-bit mov instructions. While the code tried to implement this, the compiler failed to create fast instructions. The resulting binary instructions were even slower than cfb_fillrect(), which uses the same algorithm, but operates on I/O memory. A microbenchmark measures the average number of CPU cycles for sys_fillrect() after a stabilizing period of a few minutes (i7-4790, FullHD, simpledrm, kernel with debugging). The value for CFB is given as a reference. sys_fillrect(), new: 26586 cycles sys_fillrect(), old: 166603 cycles cfb_fillrect(): 41012 cycles In the optimized case, sys_fillrect() is now ~6x faster than before and ~1.5x faster than the CFB implementation. Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Reviewed-by: Sam Ravnborg --- drivers/video/fbdev/core/sysfillrect.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/drivers/video/fbdev/core/sysfillrect.c b/drivers/video/fbdev/core/sysfillrect.c index 33ee3d34f9d2..bcdcaeae6538 100644 --- a/drivers/video/fbdev/core/sysfillrect.c +++ b/drivers/video/fbdev/core/sysfillrect.c @@ -50,19 +50,9 @@ bitfill_aligned(struct fb_info *p, unsigned long *dst, int dst_idx, /* Main chunk */ n /= bits; - while (n >= 8) { - *dst++ = pat; - *dst++ = pat; - *dst++ = pat; - *dst++ = pat; - *dst++ = pat; - *dst++ = pat; - *dst++ = pat; - *dst++ = pat; - n -= 8; - } - while (n--) - *dst++ = pat; + memset_l(dst, pat, n); + dst += n; + /* Trailing bits */ if (last) *dst = comp(pat, *dst, last); From patchwork Wed Feb 23 19:38:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 545407 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0F0DC4332F for ; Wed, 23 Feb 2022 19:38:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244474AbiBWTih (ORCPT ); Wed, 23 Feb 2022 14:38:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238574AbiBWTih (ORCPT ); Wed, 23 Feb 2022 14:38:37 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2FFB848E6B for ; Wed, 23 Feb 2022 11:38:09 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id BD17B1F44C; Wed, 23 Feb 2022 19:38:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1645645087; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N+GbnOGSeR3X9TVxFGABxV5nEPCZ3RUvOlA//TY0ScI=; b=nYz7FNsAjd1IIOARUyXyPa+7heUpaOGS7DQ1SFaIasN1VX3DQ6ROtnFIZpLgqzqSGvzags TRPaT8RN7BzyJzxvRVlTp+/+e/msZPGWd9eu8gbCnmv+AuYigrdJuZPzn3zKTC4vdalN9Q j1/rHR99mURusjp2N95xv6UH3GbIrFI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1645645087; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N+GbnOGSeR3X9TVxFGABxV5nEPCZ3RUvOlA//TY0ScI=; b=cpJfvzZ3AXcc30GzjxW9hlXVk6MDPiAK8GhocIRZuGfWMMdauSjPcTYW/J22NbOIxIkF5b YAZy/a0eI1UNSbBA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 856FF13C7B; Wed, 23 Feb 2022 19:38:07 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id IDODHx+NFmKfUgAAMHmgww (envelope-from ); Wed, 23 Feb 2022 19:38:07 +0000 From: Thomas Zimmermann To: daniel@ffwll.ch, deller@gmx.de, javierm@redhat.com, geert@linux-m68k.org, sam@ravnborg.org, kraxel@redhat.com, ppaalanen@gmail.com Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, Thomas Zimmermann Subject: [PATCH v3 2/5] fbdev: Improve performance of sys_imageblit() Date: Wed, 23 Feb 2022 20:38:01 +0100 Message-Id: <20220223193804.18636-3-tzimmermann@suse.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220223193804.18636-1-tzimmermann@suse.de> References: <20220223193804.18636-1-tzimmermann@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Improve the performance of sys_imageblit() by manually unrolling the inner blitting loop and moving some invariants out. The compiler failed to do this automatically. The resulting binary code was even slower than the cfb_imageblit() helper, which uses the same algorithm, but operates on I/O memory. A microbenchmark measures the average number of CPU cycles for sys_imageblit() after a stabilizing period of a few minutes (i7-4790, FullHD, simpledrm, kernel with debugging). The value for CFB is given as a reference. sys_imageblit(), new: 25934 cycles sys_imageblit(), old: 35944 cycles cfb_imageblit(): 30566 cycles In the optimized case, sys_imageblit() is now ~30% faster than before and ~20% faster than cfb_imageblit(). v2: * move switch out of inner loop (Gerd) * remove test for alignment of dst1 (Sam) Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Acked-by: Sam Ravnborg --- drivers/video/fbdev/core/sysimgblt.c | 49 +++++++++++++++++++++------- 1 file changed, 38 insertions(+), 11 deletions(-) diff --git a/drivers/video/fbdev/core/sysimgblt.c b/drivers/video/fbdev/core/sysimgblt.c index a4d05b1b17d7..722c327a381b 100644 --- a/drivers/video/fbdev/core/sysimgblt.c +++ b/drivers/video/fbdev/core/sysimgblt.c @@ -188,23 +188,29 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p, { u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel; u32 ppw = 32/bpp, spitch = (image->width + 7)/8; - u32 bit_mask, end_mask, eorx, shift; + u32 bit_mask, eorx; const char *s = image->data, *src; u32 *dst; - const u32 *tab = NULL; + const u32 *tab; + size_t tablen; + u32 colortab[16]; int i, j, k; switch (bpp) { case 8: tab = fb_be_math(p) ? cfb_tab8_be : cfb_tab8_le; + tablen = 16; break; case 16: tab = fb_be_math(p) ? cfb_tab16_be : cfb_tab16_le; + tablen = 4; break; case 32: - default: tab = cfb_tab32; + tablen = 2; break; + default: + return; } for (i = ppw-1; i--; ) { @@ -218,19 +224,40 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p, eorx = fgx ^ bgx; k = image->width/ppw; + for (i = 0; i < tablen; ++i) + colortab[i] = (tab[i] & eorx) ^ bgx; + for (i = image->height; i--; ) { dst = dst1; - shift = 8; src = s; - for (j = k; j--; ) { - shift -= ppw; - end_mask = tab[(*src >> shift) & bit_mask]; - *dst++ = (end_mask & eorx) ^ bgx; - if (!shift) { - shift = 8; - src++; + switch (ppw) { + case 4: /* 8 bpp */ + for (j = k; j; j -= 2, ++src) { + *dst++ = colortab[(*src >> 4) & bit_mask]; + *dst++ = colortab[(*src >> 0) & bit_mask]; + } + break; + case 2: /* 16 bpp */ + for (j = k; j; j -= 4, ++src) { + *dst++ = colortab[(*src >> 6) & bit_mask]; + *dst++ = colortab[(*src >> 4) & bit_mask]; + *dst++ = colortab[(*src >> 2) & bit_mask]; + *dst++ = colortab[(*src >> 0) & bit_mask]; + } + break; + case 1: /* 32 bpp */ + for (j = k; j; j -= 8, ++src) { + *dst++ = colortab[(*src >> 7) & bit_mask]; + *dst++ = colortab[(*src >> 6) & bit_mask]; + *dst++ = colortab[(*src >> 5) & bit_mask]; + *dst++ = colortab[(*src >> 4) & bit_mask]; + *dst++ = colortab[(*src >> 3) & bit_mask]; + *dst++ = colortab[(*src >> 2) & bit_mask]; + *dst++ = colortab[(*src >> 1) & bit_mask]; + *dst++ = colortab[(*src >> 0) & bit_mask]; } + break; } dst1 += p->fix.line_length; s += spitch; From patchwork Wed Feb 23 19:38:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 545406 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46B2FC433FE for ; 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Wed, 23 Feb 2022 19:38:08 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 0PHwECCNFmKfUgAAMHmgww (envelope-from ); Wed, 23 Feb 2022 19:38:08 +0000 From: Thomas Zimmermann To: daniel@ffwll.ch, deller@gmx.de, javierm@redhat.com, geert@linux-m68k.org, sam@ravnborg.org, kraxel@redhat.com, ppaalanen@gmail.com Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, Thomas Zimmermann Subject: [PATCH v3 5/5] drm: Add TODO item for optimizing format helpers Date: Wed, 23 Feb 2022 20:38:04 +0100 Message-Id: <20220223193804.18636-6-tzimmermann@suse.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220223193804.18636-1-tzimmermann@suse.de> References: <20220223193804.18636-1-tzimmermann@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Add a TODO item for optimizing blitting and format-conversion helpers in DRM and fbdev. There's always demand for faster graphics output. Signed-off-by: Thomas Zimmermann Acked-by: Sam Ravnborg Reviewed-by: Javier Martinez Canillas --- Documentation/gpu/todo.rst | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 7bf7f2111696..7f113c6a02dd 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -241,6 +241,28 @@ Contact: Thomas Zimmermann , Daniel Vetter Level: Advanced +Benchmark and optimize blitting and format-conversion function +-------------------------------------------------------------- + +Drawing to dispay memory quickly is crucial for many applications' +performance. + +On at least x86-64, sys_imageblit() is significantly slower than +cfb_imageblit(), even though both use the same blitting algorithm and +the latter is written for I/O memory. It turns out that cfb_imageblit() +uses movl instructions, while sys_imageblit apparently does not. This +seems to be a problem with gcc's optimizer. DRM's format-conversion +heleprs might be subject to similar issues. + +Benchmark and optimize fbdev's sys_() helpers and DRM's format-conversion +helpers. In cases that can be further optimized, maybe implement a different +algorithm, For micro-optimizations, use movl/movq instructions explicitly. +That might possibly require architecture specific helpers (e.g., storel() +storeq()). + +Contact: Thomas Zimmermann + +Level: Intermediate drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup -----------------------------------------------------------------