From patchwork Mon Sep 9 07:35:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 11137379 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F0F8E76 for ; Mon, 9 Sep 2019 07:37:31 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 D67A921A4C for ; Mon, 9 Sep 2019 07:37:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D67A921A4C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1i7EDY-00053n-6T; Mon, 09 Sep 2019 07:36:08 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1i7EDW-00053b-7m for xen-devel@lists.xenproject.org; Mon, 09 Sep 2019 07:36:06 +0000 X-Inumbo-ID: 783d0f12-d2d4-11e9-b299-bc764e2007e4 Received: from mx1.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 783d0f12-d2d4-11e9-b299-bc764e2007e4; Mon, 09 Sep 2019 07:36:00 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 17948ADEF; Mon, 9 Sep 2019 07:36:00 +0000 (UTC) From: Juergen Gross To: xen-devel@lists.xenproject.org Date: Mon, 9 Sep 2019 09:35:55 +0200 Message-Id: <20190909073557.16168-4-jgross@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190909073557.16168-1-jgross@suse.com> References: <20190909073557.16168-1-jgross@suse.com> Subject: [Xen-devel] [PATCH v6 3/5] xen: refactor debugtrace data X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Juergen Gross , Stefano Stabellini , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ian Jackson , Tim Deegan , Julien Grall , Jan Beulich MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" As a preparation for per-cpu buffers do a little refactoring of the debugtrace data: put the needed buffer admin data into the buffer as it will be needed for each buffer. In order not to limit buffer size switch the related fields from unsigned int to unsigned long, as on huge machines with RAM in the TB range it might be interesting to support buffers >4GB. While at it switch debugtrace_send_to_console and debugtrace_used to bool and delete an empty line. Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich --- V4: - renamed struct debugtrace_data_s (Jan Beulich) - renamed debtr_data (Jan Beulich) - remove unneeded condition (Jan Beulich) - recalc debugtrace_bytes (Jan Beulich) V6: - undo putting bytes into struct debugtrace_data (Jan Beulich) --- xen/common/debugtrace.c | 70 ++++++++++++++++++++++++++++--------------------- 1 file changed, 40 insertions(+), 30 deletions(-) diff --git a/xen/common/debugtrace.c b/xen/common/debugtrace.c index 07e2746846..51ab41f7a7 100644 --- a/xen/common/debugtrace.c +++ b/xen/common/debugtrace.c @@ -15,34 +15,40 @@ #include /* Send output direct to console, or buffer it? */ -static volatile int debugtrace_send_to_console; +static volatile bool debugtrace_send_to_console; -static char *debugtrace_buf; /* Debug-trace buffer */ -static unsigned int debugtrace_prd; /* Producer index */ -static unsigned int debugtrace_kilobytes = 128, debugtrace_bytes; -static unsigned int debugtrace_used; +struct debugtrace_data { + unsigned long prd; /* Producer index. */ + char buf[]; +}; + +static struct debugtrace_data *dt_data; + +static unsigned int debugtrace_kilobytes = 128; +static unsigned long debugtrace_bytes; static bool debugtrace_buf_empty; +static bool debugtrace_used; static DEFINE_SPINLOCK(debugtrace_lock); integer_param("debugtrace", debugtrace_kilobytes); static void debugtrace_dump_worker(void) { - if ( (debugtrace_bytes == 0) || !debugtrace_used ) + if ( !debugtrace_used ) return; printk("debugtrace_dump() starting\n"); /* Print oldest portion of the ring. */ - if ( debugtrace_buf[debugtrace_prd] != '\0' ) - console_serial_puts(&debugtrace_buf[debugtrace_prd], - debugtrace_bytes - debugtrace_prd); + if ( dt_data->buf[dt_data->prd] != '\0' ) + console_serial_puts(&dt_data->buf[dt_data->prd], + debugtrace_bytes - dt_data->prd); /* Print youngest portion of the ring. */ - debugtrace_buf[debugtrace_prd] = '\0'; - console_serial_puts(&debugtrace_buf[0], debugtrace_prd); + dt_data->buf[dt_data->prd] = '\0'; + console_serial_puts(&dt_data->buf[0], dt_data->prd); - memset(debugtrace_buf, '\0', debugtrace_bytes); - debugtrace_prd = 0; + memset(dt_data->buf, '\0', debugtrace_bytes); + dt_data->prd = 0; debugtrace_buf_empty = true; printk("debugtrace_dump() finished\n"); @@ -68,7 +74,6 @@ static void debugtrace_toggle(void) spin_unlock_irqrestore(&debugtrace_lock, flags); watchdog_enable(); - } void debugtrace_dump(void) @@ -90,26 +95,27 @@ static void debugtrace_add_to_buf(char *buf) for ( p = buf; *p != '\0'; p++ ) { - debugtrace_buf[debugtrace_prd++] = *p; - if ( debugtrace_prd == debugtrace_bytes ) - debugtrace_prd = 0; + dt_data->buf[dt_data->prd++] = *p; + if ( dt_data->prd == debugtrace_bytes ) + dt_data->prd = 0; } } void debugtrace_printk(const char *fmt, ...) { static char buf[1024], last_buf[1024]; - static unsigned int count, last_count, last_prd; + static unsigned int count, last_count; + static unsigned long last_prd; char cntbuf[24]; va_list args; unsigned long flags; unsigned int nr; - if ( debugtrace_bytes == 0 ) + if ( !dt_data ) return; - debugtrace_used = 1; + debugtrace_used = true; spin_lock_irqsave(&debugtrace_lock, flags); @@ -129,14 +135,14 @@ void debugtrace_printk(const char *fmt, ...) if ( debugtrace_buf_empty || strcmp(buf, last_buf) ) { debugtrace_buf_empty = false; - last_prd = debugtrace_prd; + last_prd = dt_data->prd; last_count = ++count; safe_strcpy(last_buf, buf); snprintf(cntbuf, sizeof(cntbuf), "%u ", count); } else { - debugtrace_prd = last_prd; + dt_data->prd = last_prd; snprintf(cntbuf, sizeof(cntbuf), "%u-%u ", last_count, ++count); } debugtrace_add_to_buf(cntbuf); @@ -154,23 +160,27 @@ static void debugtrace_key(unsigned char key) static int __init debugtrace_init(void) { int order; - unsigned int kbytes, bytes; + unsigned long kbytes; + struct debugtrace_data *data; /* Round size down to next power of two. */ while ( (kbytes = (debugtrace_kilobytes & (debugtrace_kilobytes-1))) != 0 ) debugtrace_kilobytes = kbytes; - bytes = debugtrace_kilobytes << 10; - if ( bytes == 0 ) + debugtrace_bytes = debugtrace_kilobytes << 10; + if ( debugtrace_bytes == 0 ) return 0; - order = get_order_from_bytes(bytes); - debugtrace_buf = alloc_xenheap_pages(order, 0); - ASSERT(debugtrace_buf != NULL); + order = get_order_from_bytes(debugtrace_bytes); + data = alloc_xenheap_pages(order, 0); + if ( !data ) + return -ENOMEM; - memset(debugtrace_buf, '\0', bytes); + debugtrace_bytes = PAGE_SIZE << order; + memset(data, '\0', debugtrace_bytes); + debugtrace_bytes -= sizeof(*data); - debugtrace_bytes = bytes; + dt_data = data; register_keyhandler('T', debugtrace_key, "toggle debugtrace to console/buffer", 0);