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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_REPLYTO_END_DIGIT, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 6F330C433ED for ; Thu, 20 May 2021 16:51:48 +0000 (UTC) Received: from lists.lttng.org (lists.lttng.org [167.114.26.123]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 965FD611BD for ; Thu, 20 May 2021 16:51:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 965FD611BD Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=lists.lttng.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lttng-dev-bounces@lists.lttng.org Received: from lists-lttng01.efficios.com (localhost [IPv6:::1]) by lists.lttng.org (Postfix) with ESMTP id 4FmG3k1YKQz1sCJ; Thu, 20 May 2021 12:51:46 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=lists.lttng.org; s=default; t=1621529506; bh=MYiJA0YAoCxd1ZjBNpKziOkl30SWAwOOd50M9/QHqXk=; h=References:In-Reply-To:Date:To:Cc:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From:Reply-To:From; b=QjzFCeQqSeZLRpSJCm3I0G4+gFSoSHWjMGUT09MquCS8Ol7D936u8E1r8zmQhlUsm k/bgXd4Z3i9Slizb5knHqzafp9r9DCg+sSe0sacOrQVWVj1zMOZP4hG7a7kuGN3q0q 7qZtA0xAJzHkRUH1wAtglQHiTWkV7SED8MfRTwIz7YYqWF6PfyD6sJ8HvLCYjmn50B DO5ImOfuwjPO5wRJRVYXjttbjA/C0I7HiGBhxgT0NpsxSIde5M8+psGXUk0yi+Mhbx cuYLmOYL96zrrXoG1dIT0nb9q4PDQLgG0KEJe+Gu9KQd0SiSYKZVH4SAncCljgbDzQ HwvGmBrVyRt4w== Received: from mail-oi1-x22a.google.com (mail-oi1-x22a.google.com [IPv6:2607:f8b0:4864:20::22a]) by lists.lttng.org (Postfix) with ESMTPS id 4FmG3h6QNQz1sCG for ; Thu, 20 May 2021 12:51:44 -0400 (EDT) Received: by mail-oi1-x22a.google.com with SMTP id y76so7733092oia.6 for ; Thu, 20 May 2021 09:51:44 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=qqn/lS5w114nKDlBoBYiuN4g9wxGm7wmjwfBbj2CqAo=; b=fRjmpsAgouwK7XtP0IJ2JIfJaPIS4UfiDzoS1wFLWpvkOluXhXJ6GcunSh3Unj0+mD fYiw3jZNZNyWIh8hNmCiC/prgswA46SzxaHtlPv0UaYiNDMOoLDldlAER8/a2YHazPvx uM8HfY1780WUjYtTt5ZMShmogOSZLVE1WNoy1jlDhE5ucbhxPtSeTS1FNBrp0/0gtwAq 2xtcpUEzKJPwcsZ7ZuXtig69JufvG9FOIdQvzGoHHtjaKcyiZ1WbL0q4O7SOAh+brNpT VlFygMVm7aGrVazICaGic4KWMhugssHCMgCpJK1BQJ7ZruQAG/9yd+SpnHeoBITSFVXa ytyw== X-Gm-Message-State: AOAM53356Pz3rxEPQWy4gS9gn5o30goeZpvSCXvgyxqbrNRxe+xKWoq2 n0BI6/Gr1RZUpgTbiBOknt/Q+LO3/oJ7itLLBwY= X-Google-Smtp-Source: ABdhPJwG62G5lAEj88Fpu8hi7UB/ltOwUAIl+Dbf9ZycrfG5lapbC9nHIM1cYfyp/7HOYQxQZqgJjcBlWY2fReLbNIw= X-Received: by 2002:aca:acc7:: with SMTP id v190mr3980687oie.28.1621529504093; Thu, 20 May 2021 09:51:44 -0700 (PDT) MIME-Version: 1.0 References: <20210520121807.55428-1-nolange79@gmail.com> <1600729511.52338.1621520352970.JavaMail.zimbra@efficios.com> <982122605.52445.1621524098787.JavaMail.zimbra@efficios.com> <523808152.52514.1621527935563.JavaMail.zimbra@efficios.com> In-Reply-To: <523808152.52514.1621527935563.JavaMail.zimbra@efficios.com> Date: Thu, 20 May 2021 18:51:33 +0200 Message-ID: To: Mathieu Desnoyers Cc: lttng-dev Subject: Re: [lttng-dev] [PATCH lttng-ust] Improve tracelog handling, reduce exported functions X-BeenThere: lttng-dev@lists.lttng.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: LTTng development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Norbert Lange via lttng-dev Reply-To: Norbert Lange Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: lttng-dev-bounces@lists.lttng.org Sender: "lttng-dev" Am Do., 20. Mai 2021 um 18:25 Uhr schrieb Mathieu Desnoyers : > > ----- On May 20, 2021, at 11:54 AM, Norbert Lange nolange79@gmail.com wrote: > [...] > > >> What prevents you from linking against lttng-ust.so again ? > > > > I did not poke around enough with Lttng to be confident it wont have > > side effects, > > I really don't want it active in production. It doesn't seem there is > > much public knowledge with Xenomai either. > > lttng-ust.so will spawn threads, lttng-ust-tracepoint.so is mostly passive, > > There is indeed a split between instrumentation and runtime threads done > with lttng-ust-tracepoint.so vs lttng-ust.so. > > I understand that this split is missing for tracelog and tracef, and > would be a good thing to have. > > I would be interested to move the tracelog and tracef implementation > from liblttng-ust.so to liblttng-ust-tracepoint.so, even this late > in the -rc cycle, because all users of tracelog/tracef need to link > against liblttng-ust-tracepoint.so anyway. So moving these symbols > should not affect anyone. > > Can you give it a try and let me know if it works for you ? Will take some time, whats the timeframe you need for feedback? > > So Id want a dynamic tracepoint-provider than i can dlopen (so that > > the signal masks are inherited, > > I hope you dont touch them). > > The signals are all blocked for lttng-ust listener threads. We don't > modify the signal masks in the tracepoint probes. Not sure which is > the target of your question though. The first one, if i'd preloaded lttng-ust and you dont mask signals, then those could end up in the realtime threads. Every Xenomai Thread has a background Linux Thread that's idle when realtime is active, ironically making them perfect targets for signal delivery > > > > > Of course I could just remove all lttng libraries on the production > > system aswell. Still doesnt change that > > tracelog and tracef doesnt work that way. > > Would moving the tracelog/tracef implementation to liblttng-ust-tracepoint.so > solve your issues ? Yes, definitely. They should then work identically to other tracepoints with TRACEPOINT_PROBE_DYNAMIC_LINKAGE. > > > > > I implemented my own tracelog/tracef using the normal lttng > > tracepoints for now, they totally break on source level with 2.13 > > aswell ;) > > is it ok if I do this to access them: > > > > #define TRACEPOINT_DEFINE > > #define TRACEPOINT_PROBE_DYNAMIC_LINKAGE > > // 2.12 > > // #include > > // #include > > // 2.13 > > #include > > #include > > > > ie. I would load lttng-ust.so later and can then use those tracepoints. > > Reimplementing the tracelog/tracef providers is not an intended use-case. > I'd very much prefer if we move their implementation to > liblttng-ust-tracepoint.so. FWIW it works, and ill use it for a while (cant just swap out libraries everywhere now). Of course Id love a upstream solution. Norbert _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev