From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 773C8C11D2F for ; Mon, 24 Feb 2020 11:54:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F8FF2084E for ; Mon, 24 Feb 2020 11:54:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aUuGHZy/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727318AbgBXLyP (ORCPT ); Mon, 24 Feb 2020 06:54:15 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:42097 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726778AbgBXLyO (ORCPT ); Mon, 24 Feb 2020 06:54:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582545253; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=k1yNrKubK76pLZB/Z3cuqDBCWEfyVtNMilq8oB52aCc=; b=aUuGHZy/Tqwi1Jjw6Cin3wpTXPODkIUTthL0VHNDyuApury4JZYVJyEGjMGnrEKXm3eh1r mXeg+hUOs2o6silcW3fOoxAAwYsaw6AVpQwt7wZN7JyZEg/3P0Y7n09QqHu17c34Sd65rO qAB6JpHE+dyTb7JUGUZ7WV6BvA/0Hr4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-275-LUx_wFtWM7KhiA8XDwm_Uw-1; Mon, 24 Feb 2020 06:54:12 -0500 X-MC-Unique: LUx_wFtWM7KhiA8XDwm_Uw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BE23318C35A4; Mon, 24 Feb 2020 11:54:10 +0000 (UTC) Received: from krava (ovpn-204-56.brq.redhat.com [10.40.204.56]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3B47091840; Mon, 24 Feb 2020 11:54:06 +0000 (UTC) Date: Mon, 24 Feb 2020 12:54:03 +0100 From: Jiri Olsa To: Sebastian Andrzej Siewior Cc: Steven Rostedt , Jiri Olsa , linux-rt-users@vger.kernel.org, Thomas Gleixner , Juri Lelli , Arnaldo Carvalho de Melo Subject: Re: [PATCH RT] tracing: make preempt_lazy and migrate_disable counter smaller Message-ID: <20200224115403.GD16664@krava> References: <20200221153541.681468-1-jolsa@kernel.org> <20200221104922.5ea8bb5f@gandalf.local.home> <20200221161030.GC657629@krava> <20200221112152.031b4230@gandalf.local.home> <20200221163735.53wt2fqoajcuj2js@linutronix.de> <20200221174419.7r5zxfkvz4yrndi2@linutronix.de> <20200221204957.GE657629@krava> <20200224100104.sbupmfe2oehmsrrb@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200224100104.sbupmfe2oehmsrrb@linutronix.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On Mon, Feb 24, 2020 at 11:01:04AM +0100, Sebastian Andrzej Siewior wrote: > On 2020-02-21 21:49:57 [+0100], Jiri Olsa wrote: > > On Fri, Feb 21, 2020 at 06:44:19PM +0100, Sebastian Andrzej Siewior wrote: > > > The migrate_disable counter should not exceed 255 so it is enough to > > > store it in an 8bit field. > > > With this change we can move the `preempt_lazy_count' member into the > > > gap so the whole struct shrinks by 4 bytes to 12 bytes in total. > > > > > > Signed-off-by: Sebastian Andrzej Siewior > > > --- > > > include/linux/trace_events.h | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h > > > index f3b1ef07e4a5f..c8b3f06cb5ed7 100644 > > > --- a/include/linux/trace_events.h > > > +++ b/include/linux/trace_events.h > > > @@ -62,9 +62,9 @@ struct trace_entry { > > > unsigned char flags; > > > unsigned char preempt_count; > > > int pid; > > > - unsigned short migrate_disable; > > > - unsigned short padding; > > > + unsigned char migrate_disable; > > > unsigned char preempt_lazy_count; > > > + unsigned short padding; > > > > also we still need to put preempt_lazy_count as common field: > > > > __common_field(unsigned char, preempt_lazy_count); > > so I need to update the struct as I did (and drop the padding field like > Steven suggested) and then do the "same" change to > "trace_define_common_fields" ? yep, AFAICS that's it thanks, jirka