From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752429AbaEVWoq (ORCPT ); Thu, 22 May 2014 18:44:46 -0400 Received: from e39.co.us.ibm.com ([32.97.110.160]:60512 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751873AbaEVWop (ORCPT ); Thu, 22 May 2014 18:44:45 -0400 From: Cody P Schafer To: Benjamin Herrenschmidt , Cody P Schafer , Michael Ellerman Cc: peterz@infradead.org, michael@ellerman.id.au, mingo@redhat.com, paulus@samba.org, acme@ghostprotocols.net, scottwood@freescale.com, sfr@canb.auug.org.au, imunsie@au1.ibm.com, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v2] powerpc/perf/hv-24x7: use kmem_cache instead of aligned stack allocations Date: Thu, 22 May 2014 15:44:25 -0700 Message-Id: <1400798673-27522-1-git-send-email-cody@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <537E78AD.1040409@linux.vnet.ibm.com> References: <537E78AD.1040409@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14052222-9332-0000-0000-000000E0AFE9 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ian pointed out the use of __aligned(4096) caused rather large stack consumption in single_24x7_request(), so use the kmem_cache hv_page_cache (which we've already got set up for other allocations) insead of allocating locally. Reported-by: Ian Munsie Signed-off-by: Cody P Schafer --- In v2: - remove duplicate exit path arch/powerpc/perf/hv-24x7.c | 48 +++++++++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c index e0766b8..998863b 100644 --- a/arch/powerpc/perf/hv-24x7.c +++ b/arch/powerpc/perf/hv-24x7.c @@ -294,7 +294,7 @@ static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix, u16 lpar, u64 *res, bool success_expected) { - unsigned long ret; + unsigned long ret = -ENOMEM; /* * request_buffer and result_buffer are not required to be 4k aligned, @@ -304,7 +304,27 @@ static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix, struct reqb { struct hv_24x7_request_buffer buf; struct hv_24x7_request req; - } __packed __aligned(4096) request_buffer = { + } __packed *request_buffer; + struct resb { + struct hv_24x7_data_result_buffer buf; + struct hv_24x7_result res; + struct hv_24x7_result_element elem; + __be64 result; + } __packed *result_buffer; + + BUILD_BUG_ON(sizeof(*request_buffer) > 4096); + BUILD_BUG_ON(sizeof(*result_buffer) > 4096); + + request_buffer = kmem_cache_alloc(hv_page_cache, GFP_USER); + + if (!request_buffer) + goto out_reqb; + + result_buffer = kmem_cache_zalloc(hv_page_cache, GFP_USER); + if (!result_buffer) + goto out_resb; + + *request_buffer = (struct reqb) { .buf = { .interface_version = HV_24X7_IF_VERSION_CURRENT, .num_requests = 1, @@ -320,28 +340,26 @@ static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix, } }; - struct resb { - struct hv_24x7_data_result_buffer buf; - struct hv_24x7_result res; - struct hv_24x7_result_element elem; - __be64 result; - } __packed __aligned(4096) result_buffer = {}; - ret = plpar_hcall_norets(H_GET_24X7_DATA, - virt_to_phys(&request_buffer), sizeof(request_buffer), - virt_to_phys(&result_buffer), sizeof(result_buffer)); + virt_to_phys(request_buffer), sizeof(*request_buffer), + virt_to_phys(result_buffer), sizeof(*result_buffer)); if (ret) { if (success_expected) pr_err_ratelimited("hcall failed: %d %#x %#x %d => 0x%lx (%ld) detail=0x%x failing ix=%x\n", domain, offset, ix, lpar, ret, ret, - result_buffer.buf.detailed_rc, - result_buffer.buf.failing_request_ix); - return ret; + result_buffer->buf.detailed_rc, + result_buffer->buf.failing_request_ix); + goto out_hcall; } - *res = be64_to_cpu(result_buffer.result); + *res = be64_to_cpu(result_buffer->result); +out_hcall: + kfree(result_buffer); +out_resb: + kfree(request_buffer); +out_reqb: return ret; } -- 1.9.3