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=-11.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_SANE_2 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 197B9C433E0 for ; Tue, 4 Aug 2020 02:46:05 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 106E52065E for ; Tue, 4 Aug 2020 02:46:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="bDJ6gluw"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="Ikwe7hsm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 106E52065E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Date:To:From: Subject:Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=1fPL3Bl9SlJAwao69fO2duoc+WpiSVvE/vA6WmZE8Hs=; b=bDJ6gluwp8zctzdlovHdfz+pI cQs1XspMja76L2ysA2woWbm7onGGKLUFIOzKmtQjXQ8iaGVx5lpMfQQCF+imkiKxHr8zty4opquM6 ZzAncQS+jH8OjutR/p85pUeddQGAgAZxkuNYRMlianA3ioC8x31izBNeO3RRg11QCku/WO2LJ3fYw fTwSoG9dCFt8//IulbfAYt3Scw/o+XdG5kudg1QdtYnI6jxnFJjQcOAYAJ1f3aYyUiOLPYf7gX9HI HrqUHcWZdLyoSy+ZLDwIJaQzbAN4tFxr/yw6UxByQ/5tMRlib2EF1jiKXf6/v9BhBiPuJXOxdx2Pd z56406pbg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k2mxe-0008OC-Nj; Tue, 04 Aug 2020 02:45:54 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k2mxc-0008Mn-9g for linux-mediatek@lists.infradead.org; Tue, 04 Aug 2020 02:45:53 +0000 X-UUID: 8bde8d70ef484bf196853ecc4ba168b9-20200803 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Transfer-Encoding:MIME-Version:Content-Type:References:In-Reply-To:Date:CC:To:From:Subject:Message-ID; bh=BUJdISNL45J7vXInlHBIZKujtbVyNSjWJjnGfPo7yno=; b=Ikwe7hsmg4aezzuWK6ZshO73JfPz2vR1lOUH0CUFd/XV681nRPorQ1V3o+mbNF5roQ8RKWmXHKZiK1W1sEz5uVcAieJqIyxhGMgz00HaBXjl//ZbrZVptAmBNDVt4wDSvDgFCM7vNppt0pZjQ6gvqTgBnPr2TAxC2/4P+7F4a8c=; X-UUID: 8bde8d70ef484bf196853ecc4ba168b9-20200803 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLS) with ESMTP id 2087644307; Mon, 03 Aug 2020 18:45:49 -0800 Received: from mtkmbs08n1.mediatek.inc (172.21.101.55) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 3 Aug 2020 19:45:43 -0700 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs08n1.mediatek.inc (172.21.101.55) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 4 Aug 2020 10:45:45 +0800 Received: from [172.21.77.33] (172.21.77.33) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 4 Aug 2020 10:45:45 +0800 Message-ID: <1596509145.5207.21.camel@mtkswgap22> Subject: Re: [PATCH v6 2/3] binder: add trace at free transaction. From: Frankie Chang To: Todd Kjos Date: Tue, 4 Aug 2020 10:45:45 +0800 In-Reply-To: References: <1595252430.5899.6.camel@mtkswgap22> <1595906401-11985-1-git-send-email-Frankie.Chang@mediatek.com> <1595906401-11985-3-git-send-email-Frankie.Chang@mediatek.com> <1596424276.5207.13.camel@mtkswgap22> X-Mailer: Evolution 3.2.3-0ubuntu6 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200803_224552_592943_DFDF5986 X-CRM114-Status: GOOD ( 36.05 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wsd_upstream , Greg Kroah-Hartman , LKML , Arve =?ISO-8859-1?Q?Hj=F8nnev=E5g?= , Jian-Min Liu , linux-mediatek@lists.infradead.org, Joel Fernandes , Martijn Coenen , Christian Brauner Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Mon, 2020-08-03 at 08:12 -0700, Todd Kjos wrote: > On Sun, Aug 2, 2020 at 8:11 PM Frankie Chang wrote: > > > > On Fri, 2020-07-31 at 11:50 -0700, Todd Kjos wrote: > > > On Mon, Jul 27, 2020 at 8:28 PM Frankie Chang > > > wrote: > > > > > > > > From: "Frankie.Chang" > > > > > > > > Since the original trace_binder_transaction_received cannot > > > > precisely present the real finished time of transaction, adding a > > > > trace_binder_txn_latency_free at the point of free transaction > > > > may be more close to it. > > > > > > > > Signed-off-by: Frankie.Chang > > > > --- > > > > drivers/android/binder.c | 6 ++++++ > > > > drivers/android/binder_trace.h | 27 +++++++++++++++++++++++++++ > > > > 2 files changed, 33 insertions(+) > > > > > > > > diff --git a/drivers/android/binder.c b/drivers/android/binder.c > > > > index 2df146f..1e6fc40 100644 > > > > --- a/drivers/android/binder.c > > > > +++ b/drivers/android/binder.c > > > > @@ -1522,6 +1522,9 @@ static void binder_free_transaction(struct binder_transaction *t) > > > > * If the transaction has no target_proc, then > > > > * t->buffer->transaction has already been cleared. > > > > */ > > > > + spin_lock(&t->lock); > > > > + trace_binder_txn_latency_free(t); > > > > + spin_unlock(&t->lock); > > > > > > Hmm. I don't prefer taking the lock just to call a trace. It doesn't > > > make clear why the lock has to be taken. I'd prefer something like: > > > > > > if (trace_binder_txn_latency_free_enabled()) { > > c > > > } > > > > > > And then the trace would use the passed-in values instead of accessing > > > via t->to_proc/to_thread. > > > > > Then we still add lock protection in the hook function, when trace is > > disable ? > > I don't understand... in the example I gave, the trace doesn't get > called if disabled. What do you mean to "add lock protection when the > trace is disabled()"? > > > > > Or we also pass these to hook function, no matter the trace is enable or > > What do you mean by "hook" function? If something has attached to the > trace, then xxx_enabled() will return true. > I'm sorry for that I misunderstand this XXX_enabled(). > > not.I think this way is more clear that the lock protects @from, > > @to_proc and @to_thread.Then, there is no need to add the lock in hook > > function. > > Why is it clearer (other than the fact that I missed including t->from > under the lock)? > I think your example is clear enough. > > > > int from_proc, from_thread, to_proc, to_thread; > > > > spin_lock(&t->lock); > > from_proc = t->from ? t->from->proc->pid : 0; > > from_thread = t->from ? t->from->pid :0; > > to_proc = t->to_proc ? t->to_proc->pid : 0; > > to_thread = t->to_thread ? t->to_thread->pid : 0; > > spin_unlock(&t->lock); > > trace_binder_txn_latency_free(t, from_proc, from_thread, to_proc, > > to_pid); > > The main feedback is I'd like to see the fields dereferenced in the > same context as the lock acquisition instead of acquiring the lock and > calling the trace function, so this code would be fine. There will be > very little contention for t->lock so using xxx_enabled() is optional. > > Since trace_binder_txn_latency_free() is called twice, it would make > sense to have a helper function to do the above. > Okay, I will make a helper function to do this in next version patch. Very thanks for your help for this. > > > > > > binder_free_txn_fixups(t); > > > > kfree(t); > > > > binder_stats_deleted(BINDER_STAT_TRANSACTION); > > > > @@ -3093,6 +3096,9 @@ static void binder_transaction(struct binder_proc *proc, > > > > kfree(tcomplete); > > > > binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); > > > > err_alloc_tcomplete_failed: > > > > + spin_lock(&t->lock); > > > > + trace_binder_txn_latency_free(t); > > > > + spin_unlock(&t->lock); > > > > kfree(t); > > > > binder_stats_deleted(BINDER_STAT_TRANSACTION); > > > > err_alloc_t_failed: > > > > diff --git a/drivers/android/binder_trace.h b/drivers/android/binder_trace.h > > > > index 6731c3c..8ac87d1 100644 > > > > --- a/drivers/android/binder_trace.h > > > > +++ b/drivers/android/binder_trace.h > > > > @@ -95,6 +95,33 @@ > > > > __entry->thread_todo) > > > > ); > > > > > > > > +TRACE_EVENT(binder_txn_latency_free, > > > > + TP_PROTO(struct binder_transaction *t), > > > > + TP_ARGS(t), > > > > + TP_STRUCT__entry( > > > > + __field(int, debug_id) > > > > + __field(int, from_proc) > > > > + __field(int, from_thread) > > > > + __field(int, to_proc) > > > > + __field(int, to_thread) > > > > + __field(unsigned int, code) > > > > + __field(unsigned int, flags) > > > > + ), > > > > + TP_fast_assign( > > > > + __entry->debug_id = t->debug_id; > > > > + __entry->from_proc = t->from ? t->from->proc->pid : 0; > > > > + __entry->from_thread = t->from ? t->from->pid : 0; > > > > + __entry->to_proc = t->to_proc ? t->to_proc->pid : 0; > > > > + __entry->to_thread = t->to_thread ? t->to_thread->pid : 0; > > > > + __entry->code = t->code; > > > > + __entry->flags = t->flags; > > > > + ), > > > > + TP_printk("transaction=%d from %d:%d to %d:%d flags=0x%x code=0x%x", > > > > + __entry->debug_id, __entry->from_proc, __entry->from_thread, > > > > + __entry->to_proc, __entry->to_thread, __entry->code, > > > > + __entry->flags) > > > > +); > > > > + > > > > TRACE_EVENT(binder_transaction, > > > > TP_PROTO(bool reply, struct binder_transaction *t, > > > > struct binder_node *target_node), > > > > -- > > > > 1.7.9.5 > > _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek