From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755443AbcBIDIt (ORCPT ); Mon, 8 Feb 2016 22:08:49 -0500 Received: from e18.ny.us.ibm.com ([129.33.205.208]:59602 "EHLO e18.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755059AbcBIDIs (ORCPT ); Mon, 8 Feb 2016 22:08:48 -0500 X-IBM-Helo: d01dlp01.pok.ibm.com X-IBM-MailFrom: sukadev@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org Date: Mon, 8 Feb 2016 19:08:30 -0800 From: Sukadev Bhattiprolu To: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH] powerpc/perf/hv-gpci: Increase request buffer size Message-ID: <20160209030830.GA4815@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Operating-System: Linux 2.0.32 on an i486 User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16020903-0045-0000-0000-00000344D73E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>From 31edd352fb7c2a72913f1977fa1bf168109089ad Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Tue, 9 Feb 2016 02:47:45 -0500 Subject: [PATCH] powerpc/perf/hv-gpci: Increase request buffer size The GPCI hcall allows for a 4K buffer but we limit the buffer to 1K. The problem with a 1K buffer is if a request results in returning more values than can be accomodated in the 1K buffer the request will fail. The buffer we are using is currently allocated on the stack and hence limited in size. Instead use a per-CPU 4K buffer like we do with 24x7 counters (hv-24x7.c). Signed-off-by: Sukadev Bhattiprolu --- arch/powerpc/perf/hv-gpci.c | 37 ++++++++++++++++++++++--------------- 1 file changed, 22 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c index 856fe6e..e6fad73 100644 --- a/arch/powerpc/perf/hv-gpci.c +++ b/arch/powerpc/perf/hv-gpci.c @@ -127,8 +127,16 @@ static const struct attribute_group *attr_groups[] = { NULL, }; +#define HGPCI_REQ_BUFFER_SIZE 4096 #define GPCI_MAX_DATA_BYTES \ - (1024 - sizeof(struct hv_get_perf_counter_info_params)) + (HGPCI_REQ_BUFFER_SIZE - sizeof(struct hv_get_perf_counter_info_params)) + +DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE]) __aligned(sizeof(uint64_t)); + +struct hv_gpci_request_buffer { + struct hv_get_perf_counter_info_params params; + uint8_t bytes[1]; +} __packed; static unsigned long single_gpci_request(u32 req, u32 starting_index, u16 secondary_index, u8 version_in, u32 offset, u8 length, @@ -137,24 +145,21 @@ static unsigned long single_gpci_request(u32 req, u32 starting_index, unsigned long ret; size_t i; u64 count; + struct hv_gpci_request_buffer *arg; + + arg = (void *)get_cpu_var(hv_gpci_reqb); + memset(arg, 0, HGPCI_REQ_BUFFER_SIZE); - struct { - struct hv_get_perf_counter_info_params params; - uint8_t bytes[GPCI_MAX_DATA_BYTES]; - } __packed __aligned(sizeof(uint64_t)) arg = { - .params = { - .counter_request = cpu_to_be32(req), - .starting_index = cpu_to_be32(starting_index), - .secondary_index = cpu_to_be16(secondary_index), - .counter_info_version_in = version_in, - } - }; + arg->params.counter_request = cpu_to_be32(req); + arg->params.starting_index = cpu_to_be32(starting_index); + arg->params.secondary_index = cpu_to_be16(secondary_index); + arg->params.counter_info_version_in = version_in; ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO, - virt_to_phys(&arg), sizeof(arg)); + virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE); if (ret) { pr_devel("hcall failed: 0x%lx\n", ret); - return ret; + goto out; } /* @@ -163,9 +168,11 @@ static unsigned long single_gpci_request(u32 req, u32 starting_index, */ count = 0; for (i = offset; i < offset + length; i++) - count |= arg.bytes[i] << (i - offset); + count |= arg->bytes[i] << (i - offset); *value = count; +out: + put_cpu_var(hv_gpci_reqb); return ret; } -- 1.8.3.1