From 48bee8a6c98e34367fa9d5e1be14109c92cbbb3b Mon Sep 17 00:00:00 2001 From: Cody P Schafer Date: Tue, 30 Sep 2014 23:03:17 -0700 Subject: [PATCH] powerpc/perf/hv-24x7: use kmem_cache instead of aligned stack allocations 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. CC: Haren Myneni Reported-by: Ian Munsie Signed-off-by: Cody P Schafer Signed-off-by: Sukadev Bhattiprolu Signed-off-by: Michael Ellerman --- arch/powerpc/perf/hv-24x7.c | 55 +++++++++++++++++++++++++------------ 1 file changed, 37 insertions(+), 18 deletions(-) diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c index 70d4f748b54b..697759d8eb16 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 { + 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_zalloc(hv_page_cache, GFP_USER); + if (!request_buffer) + goto out; + + result_buffer = kmem_cache_zalloc(hv_page_cache, GFP_USER); + if (!result_buffer) + goto out_free_request_buffer; + + *request_buffer = (struct reqb) { .buf = { .interface_version = HV_24X7_IF_VERSION_CURRENT, .num_requests = 1, @@ -320,28 +340,27 @@ 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; + 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); + goto out_free_result_buffer; } - *res = be64_to_cpu(result_buffer.result); + *res = be64_to_cpu(result_buffer->result); + +out_free_result_buffer: + kfree(result_buffer); +out_free_request_buffer: + kfree(request_buffer); +out: return ret; }