Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753778Ab3JYKeh (ORCPT ); Fri, 25 Oct 2013 06:34:37 -0400 Received: from mail-ee0-f49.google.com ([74.125.83.49]:47739 "EHLO mail-ee0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753732Ab3JYKef (ORCPT ); Fri, 25 Oct 2013 06:34:35 -0400 Date: Fri, 25 Oct 2013 12:34:32 +0200 From: Ingo Molnar To: Patrick Palka Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Paul Mackerras , Ingo Molnar Subject: Re: [PATCH] perf/ui/tui: don't force a refresh during progress update Message-ID: <20131025103432.GA4363@gmail.com> References: <1382565562-15108-1-git-send-email-patrick@parcs.ath.cx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1382565562-15108-1-git-send-email-patrick@parcs.ath.cx> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2746 Lines: 67 * Patrick Palka wrote: > Each call to tui_progress__update() would forcibly refresh the entire > screen. This is somewhat inefficient and causes noticable flickering > during the startup of perf-report, especially on large/slow terminals. > > It looks like the force-refresh in tui_progress__update() serves no > purpose other than to clear the screen so that the progress bar of a > previous operation does not subsume with that of a subsequent operation. > But we can do just that in a much more efficient manner by clearing only > the region that a previous progress bar may have occupied before > repainting the new progress bar. Then the force-refresh could be > removed with no change in visuals. > > This patch disables the slow force-refresh in tui_progress__update() and > instead calls SLsmg_fill_region() on the entire area that the progress > bar may occupy before repainting it. This change makes the startup of > perf-report much faster and appear much "smoother". > > It turns out that this was a big bottleneck in the startup speed of > perf-report -- with this patch, perf-report starts up ~1.6x faster (0.8s > vs 0.5s) on my machines. (These numbers were measured by running "time > perf report" on an 8MB perf.data and pressing 'q' immediately.) > > Cc: Peter Zijlstra > Cc: Paul Mackerras > Cc: Ingo Molnar > Signed-off-by: Patrick Palka > --- > tools/perf/ui/tui/progress.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/ui/tui/progress.c b/tools/perf/ui/tui/progress.c > index 6c2184d..641049a 100644 > --- a/tools/perf/ui/tui/progress.c > +++ b/tools/perf/ui/tui/progress.c > @@ -17,13 +17,14 @@ static void tui_progress__update(u64 curr, u64 total, const char *title) > if (total == 0) > return; > > - ui__refresh_dimensions(true); > + ui__refresh_dimensions(false); > pthread_mutex_lock(&ui__lock); > y = SLtt_Screen_Rows / 2 - 2; > SLsmg_set_color(0); > SLsmg_draw_box(y, 0, 3, SLtt_Screen_Cols); > SLsmg_gotorc(y++, 1); > SLsmg_write_string((char *)title); > + SLsmg_fill_region(y, 1, 1, SLtt_Screen_Cols - 2, ' '); > SLsmg_set_color(HE_COLORSET_SELECTED); > bar = ((SLtt_Screen_Cols - 2) * curr) / total; > SLsmg_fill_region(y, 1, 1, bar, ' '); Nice! This is something I noticed as well, never figured out the root cause of it. Acked-by: Ingo Molnar Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/