From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B85AB3F0AAD; Thu, 28 May 2026 13:13:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779974040; cv=none; b=FNlnmr9yMj/WHG46x8qGwdxPrUjjcVy/tutiAaGrbSr94zB5m/go/7ZGcSz0FkN36vlLY+2/qPpamBxpHkWIpNJcrn1feSqM3fWtnJfYua9FjqNOCOXWTitCc6784Ha/xVjSZqPQVdpWNq3ySpOu6GjK7IuCnZo/MF2IjIxL40U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779974040; c=relaxed/simple; bh=TNt4FZNUVXbUONxH6eLUa6thNygoQjXrmnVZ2euxCQM=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=j+QPJKO69UytJxkZ4ZAGbthKPuye8Qa4ChhmDASirmZ2F2Ag58NSlJB86VvddPFyLk2Ut7qcRf+3hdNMw+6WiyudBWHkWtwRtaL9nALKc24rRh4QgV2Pf2ZvuVREtuYP8EERQY47JeofTWT11hejsKs9abQrLW5O9FhPRzopzXs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf11.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id BB1214080E; Thu, 28 May 2026 13:13:51 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf11.hostedemail.com (Postfix) with ESMTPA id B74EC2002C; Thu, 28 May 2026 13:13:49 +0000 (UTC) Date: Thu, 28 May 2026 09:13:48 -0400 From: Steven Rostedt To: Tianchen Ding Cc: Masami Hiramatsu , Mathieu Desnoyers , Shuah Khan , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v2] selftests/ftrace: Fix trace_marker_raw test on 64K page kernels Message-ID: <20260528091348.71ae3aa3@fedora> In-Reply-To: <20260528022417.1813745-1-dtcccc@linux.alibaba.com> References: <20260527095438.1794905-1-dtcccc@linux.alibaba.com> <20260528022417.1813745-1-dtcccc@linux.alibaba.com> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: 19hf81xh8jp4zxqph9uo3gmz4r1aocgx X-Rspamd-Server: rspamout08 X-Rspamd-Queue-Id: B74EC2002C X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1/8mrO9fiLpeHdufBy60toekVMt5AHvoU0= X-HE-Tag: 1779974029-622999 X-HE-Meta: U2FsdGVkX1+Wg9S6O66C7CEc8TiWRZ8DoImmg1Lf/RKCwYpsua4qiXpH5wKR9UprqgDNDtLcCAC54zlDkaa1vSoKiJfdYzn5Z35xW5rK85gW9Rvgv2c4ENjgZ+xhSR3iY4lHTv1VHI0w33gAAhYke/SOs38DRvGQOl5z+8b6/ckrdjG3bWNdwSafXDiPRUT4a5gP5QZwkhPzVuDueCQA+JUBbMK/s4YQyE1u6AFs/zK85VdKgStIfyohin84zTPhNYbSjXzkl3mB/lIjrlxTsM1baRG2lyO05i6YJiA8/m3fmd6gZZRXZXN5Eh7+IXIgoH4D/Yqk4h+gWmn5rl0LDJfQ65glQfkX On Thu, 28 May 2026 10:24:17 +0800 Tianchen Ding wrote: > > diff --git a/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc > index 8e905d4fe6dd..f68f1901f65f 100644 > --- a/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc > +++ b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc > @@ -43,8 +43,11 @@ write_buffer() { > id=$1 > size=$2 > > - # write the string into the raw marker > - make_str $id $size > trace_marker_raw > + # Pipe through dd to ensure a single atomic write() syscall > + # on architectures with 64K pages, where shell's printf builtin > + # uses stdio buffering which may split the output into multiple > + # writes. > + make_str $id $size | dd of=trace_marker_raw bs=`expr $size + 4` iflag=fullblock I was looking at this more, and I'm not comfortable with the hard coded 4 above. I rather use the length of the string. Something like: str=`make_str $id $size` len=${#str} echo "$str" | dd of=trace_marker_raw bs=$len iflag=fullblock -- Steve > } > >