From owner-freebsd-drivers@freebsd.org Fri Aug 30 10:54:55 2019 Return-Path: Delivered-To: freebsd-drivers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 8E6F0CAD85; Fri, 30 Aug 2019 10:54:55 +0000 (UTC) (envelope-from shreyankfbsd@gmail.com) Received: from mail-yw1-xc29.google.com (mail-yw1-xc29.google.com [IPv6:2607:f8b0:4864:20::c29]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46KbwG4W1tz402s; Fri, 30 Aug 2019 10:54:54 +0000 (UTC) (envelope-from shreyankfbsd@gmail.com) Received: by mail-yw1-xc29.google.com with SMTP id 129so1600117ywb.8; Fri, 30 Aug 2019 03:54:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to:cc; bh=rG84iHW20UnQWjFBxnIGlbit+94wIaS18Dg1CC5iWQQ=; b=qxPeUuZKVdBA5FQ7N5T5c0Q2miMlDe9UVNsgdJex/bdOHHVWyDkr53iPvClK3YqaOV 5UD40Pgqyf9Y2ZJePudAfTH5sh6aH8ejetFvftPXwBOVpQ4Ew9p8hEk7bkgziiIAkEnF UB4Q/m81WP791kD+lZ81LPit7ceUpLrduXiXwUbaueWx9wx9zRuQ0IpEn0WMY+1bfqi9 KQA6bX5U+FDiSkd1JQbrVCEJuIcxbZFxDrK4vM+Q9PYf06qLGBWSyrGZ6JQepK87o1CI JdMlyThv4Op8ix/h0i419oadQUnyhGLqCxIVzPLztGjjbJYl1Y2/8K8HjyZqXRMTsJhM i4PA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=rG84iHW20UnQWjFBxnIGlbit+94wIaS18Dg1CC5iWQQ=; b=J5DhyMTgNIYasVShbCGxkXqoQp5f1kwYbeD5EmWyWS1WPX6uBJPV1ZFKiAKLWXHcFX UETITjs5DOD0RQbnQp9ZajPOSDkSgOB6xqUHpTotCtSWpnqI/53rGUa7wnRH/DFSLi0T iUsz/p5mtkPuSjPbgWYhjKoSS9obxWhtlMvH8OvBGwjTSLcqocDeJizJTqmsae0ZhK4l D3CnxqwhYGfVTzLHlK82QTuv0+ASojwOfNHIZpI9zOs8Tf+QTx1yxQQELnGrQvs59F0q jD9YDF4CF++0EozDPOJQVt4CBcoUg7R8VYWxsOudQKeVws4yybZpwm8Rf8Ysk7530nMf LKyA== X-Gm-Message-State: APjAAAWuFkqatVI/SgwBJDvXHZXAYP9e5HgTdppS+XuLs4KaFq+FSznE WC0ZHr+ddtuIn6YsfAWTOkI0OkaM0by8EtQul4+/cO4= X-Google-Smtp-Source: APXvYqx5MXMH3I2pRxWpzcg7EuAv504Ks+UjYFiKHY63yX/VO9W53nRjX3v1zpv51QPUy2yh9f1ojYpQJOZOLNblTsI= X-Received: by 2002:a81:4d43:: with SMTP id a64mr10535729ywb.131.1567162493160; Fri, 30 Aug 2019 03:54:53 -0700 (PDT) MIME-Version: 1.0 From: shreyank amartya Date: Fri, 30 Aug 2019 16:24:41 +0530 Message-ID: Subject: hwpmc ktrdump: failed to resolve ktr symbols To: freebsd-drivers@freebsd.org Cc: freebsd-hackers@freebsd.org X-Rspamd-Queue-Id: 46KbwG4W1tz402s X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=qxPeUuZK; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of shreyankfbsd@gmail.com designates 2607:f8b0:4864:20::c29 as permitted sender) smtp.mailfrom=shreyankfbsd@gmail.com X-Spamd-Result: default: False [-4.00 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36]; FREEMAIL_FROM(0.00)[gmail.com]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; TO_DN_NONE(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; IP_SCORE_FREEMAIL(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; IP_SCORE(0.00)[ip: (-9.39), ipnet: 2607:f8b0::/32(-2.84), asn: 15169(-2.32), country: US(-0.05)]; DKIM_TRACE(0.00)[gmail.com:+]; RCPT_COUNT_TWO(0.00)[2]; RCVD_IN_DNSWL_NONE(0.00)[9.2.c.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; NEURAL_HAM_SHORT(-1.00)[-0.996,0]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com.dwl.dnswl.org : 127.0.5.0] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: freebsd-drivers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Writing device drivers for FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 Aug 2019 10:54:55 -0000 Hi, I'm trying to collect traces from hwpmc module. I compiled the module with -DHWPMC_DEBUG option and set the sysctl kern.hwpmc.debugflags but I'm unable to retrive the traces using ktrdump. I get this error message: ktrdump: failed to resolve ktr symbols I'm guessing that this error occurs because the symbols for hwpmc module (compiled and loaded separately) are not a part of kernel. If this is the case, then how do I get those symbols. In the ktr man page its also mentioned that ddb and gdb can retrieve ktraces. I found the ddb command show ktr. But how do I invoke ddb (without a panic)? I'm unable to find how can I use gdb to view the traces (I launched kgdb but could not find a command to show kernel traces). Any idea on how to get ktrdump working? Or get the kernel traces. Thanks Shreyank From owner-freebsd-drivers@freebsd.org Fri Aug 30 16:07:21 2019 Return-Path: Delivered-To: freebsd-drivers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id E054CD1E70; Fri, 30 Aug 2019 16:07:21 +0000 (UTC) (envelope-from nparhar@gmail.com) Received: from mail-qk1-x736.google.com (mail-qk1-x736.google.com [IPv6:2607:f8b0:4864:20::736]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46Kkrm1xwlz4FxG; Fri, 30 Aug 2019 16:07:20 +0000 (UTC) (envelope-from nparhar@gmail.com) Received: by mail-qk1-x736.google.com with SMTP id w18so6628596qki.0; Fri, 30 Aug 2019 09:07:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=efKeDJjWAXaWx8IIAaUK8bYcGP3gvXT0u8vxDCpd0xc=; b=W0UqHRXFvbj8swQ8OqBD5cCOuruP6KrrnlnKfJaPL27NGWP8Le4GtGt5iGzJO4CbZp o4bX1jA8oSMUtW7s90ukwtJS5y7QnNwxYjqaqQpwxylofV0ZnrbfWp92+CeFZU2KIU96 584VFn5AQ4MJo19lDvL+fmfScCutfNvr8Of/WLkGyF47hnCh4rD0cJeRYdxk7QcFA3VL EXlbySzT23KOYpytorNu8BHBa6SofniKVnaxB+aD/1Rv2fNTi2993xNJpU/4jkATMIcE LSpMsg4OVaqmSu6HNrYSpztKSEq3IH3FR99JVtb/8ITgF4D4RcHyLY/PuXmh2C33ejeF P+dQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=efKeDJjWAXaWx8IIAaUK8bYcGP3gvXT0u8vxDCpd0xc=; b=ngBTWFYpG4KbGoUPBumWjGaJmKtn+ah11e7d1stT0hJ2441+WgApo15m5yt1sxeC8D FkaYMz8oHW7MEqKA+C88WU54V+TdheZcAMoevV7blOmh+YzyJIxRoOT5BUV3byqZLKl3 u/g6JR9bU/qTMKsn93IY1jZXzgbqDZZCbfy6wBt68f7l/T/N2THxDdLPQwCXM3q4RjRy F75+Jmu5yEEHbuv3QIVTe0Yt8lkpa4F9vbE+RQDO5+4kZ6dQFYED0ivtx8JVYRc9pY6b dKRcq23/DiamwLzPS6m+z88hcPy1IHjErId5JroDqCGj/GPl7tBbv25N4cH/vBgkvfr4 IUgQ== X-Gm-Message-State: APjAAAX/v42gQ/sZ7+JUUpf6bCgNBqhtVAyq1NyJmACsIwbDBxm47LQx /QYwqriCAQYHcHrM0AVLfY7xpkEo X-Google-Smtp-Source: APXvYqyHRw3cnRAwzyhptR+4E4X9LBcOY2YzjV+0/I7VGZGhlFrQuiH/16aXwHVq0Urq4MXcENdliw== X-Received: by 2002:ae9:e202:: with SMTP id c2mr15118816qkc.15.1567181239000; Fri, 30 Aug 2019 09:07:19 -0700 (PDT) Received: from [10.192.166.0] (stargate.chelsio.com. [12.32.117.8]) by smtp.googlemail.com with ESMTPSA id h29sm3615902qtb.46.2019.08.30.09.07.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 30 Aug 2019 09:07:18 -0700 (PDT) Subject: Re: hwpmc ktrdump: failed to resolve ktr symbols To: shreyank amartya , freebsd-drivers@freebsd.org Cc: freebsd-hackers@freebsd.org References: From: Navdeep Parhar Message-ID: <0534e1a9-af57-96cf-9ea2-ec4b30021226@gmail.com> Date: Fri, 30 Aug 2019 09:07:16 -0700 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:68.0) Gecko/20100101 Thunderbird/68.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 46Kkrm1xwlz4FxG X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=W0UqHRXF; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of nparhar@gmail.com designates 2607:f8b0:4864:20::736 as permitted sender) smtp.mailfrom=nparhar@gmail.com X-Spamd-Result: default: False [-3.99 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; NEURAL_HAM_SHORT(-0.99)[-0.992,0]; FREEMAIL_TO(0.00)[gmail.com]; FROM_EQ_ENVFROM(0.00)[]; IP_SCORE(0.00)[ip: (-9.38), ipnet: 2607:f8b0::/32(-2.84), asn: 15169(-2.32), country: US(-0.05)]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; MID_RHS_MATCH_FROM(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com.dwl.dnswl.org : 127.0.5.0]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; IP_SCORE_FREEMAIL(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[6.3.7.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; RCVD_TLS_ALL(0.00)[] X-BeenThere: freebsd-drivers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Writing device drivers for FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 Aug 2019 16:07:21 -0000 On 2019-08-30 03:54, shreyank amartya wrote: > Hi, > > I'm trying to collect traces from hwpmc module. I compiled the module with > -DHWPMC_DEBUG option and set the sysctl kern.hwpmc.debugflags but I'm > unable to retrive the traces using ktrdump. I get this error message: > > ktrdump: failed to resolve ktr symbols > > I'm guessing that this error occurs because the symbols for hwpmc module > (compiled and loaded separately) are not a part of kernel. If this is the > case, then how do I get those symbols. In the ktr man page its also > mentioned that ddb and gdb can retrieve ktraces. > > I found the ddb command show ktr. But how do I invoke ddb (without a panic)? sysctl debug.kdb.enter=1 > > I'm unable to find how can I use gdb to view the traces (I launched kgdb > but could not find a command to show kernel traces). > > Any idea on how to get ktrdump working? Or get the kernel traces. You need a kernel with KTR support. See ktr(4) for a full list of the options and other details. See "sysctl kern.conftxt" for what's in your running kernel. Regards, Navdeep From owner-freebsd-drivers@freebsd.org Sat Aug 31 20:34:03 2019 Return-Path: Delivered-To: freebsd-drivers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 2DEE8DB354; Sat, 31 Aug 2019 20:34:03 +0000 (UTC) (envelope-from shreyankfbsd@gmail.com) Received: from mail-yb1-xb36.google.com (mail-yb1-xb36.google.com [IPv6:2607:f8b0:4864:20::b36]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46LSk21KCwz3N0K; Sat, 31 Aug 2019 20:34:01 +0000 (UTC) (envelope-from shreyankfbsd@gmail.com) Received: by mail-yb1-xb36.google.com with SMTP id t15so3698562ybg.7; Sat, 31 Aug 2019 13:34:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to:cc; bh=d1frEj6sgThf89efHLok+CyF24QjJzhPZrryN/OCMTs=; b=k1FhwzuNAwUnkFPLoLubXymbNOfczAUlNUTDV0i3Y6vwCxJI/GNgWiIBT05B7Bhud9 F9dpG5kkdrbBvsU9U7VI0+wyjjYA6cmzvLWd8qECXkyeEjsO2IEIFRRlde6y1u/vVuzt CT8BVKT1nuv+InFq0tgQ3yqTX92JTfIGVZlRicbnu7lwo7Y/u0zye9UkKwPvCXYQsQn9 XlB8+Z7YqC6etLr3JV/bixFK1xeCOaXAT9NnRbUOGVmOev0v6GBf9IQEBPaiX3/jn8pK wY7Jtg1KIAb6Qsqfj7UbLjKL4PqEWXA/iEjuSGqSzNbJrlTRPve3FLqRU16xHzL4r0oy ygOA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=d1frEj6sgThf89efHLok+CyF24QjJzhPZrryN/OCMTs=; b=g4zTOmIolkSqztBf7I/P4JEuln11GhvRF4p44ezDtHajxsdZkfw5m4ctt1ATXtVqmt BLAoq63ghkhR/JJmCaqqm7dHqHmVvA/74GHFwvduyltZchIrZntp1bPYVeFvrc7D2OZr zKbh4rMVs/2FUnhWPE4g/rcafrtCq6oARJZXaleaPmiIDnBE1b13Dutn6FU9nHCZAoKe 7VZC8Nrde/3Ieic6yg0YEFBKsxET4VvDdC5uNCsR4vR8040FJWT2thqHQwbt7lZgMCaz +y/JInkixo0bAI7r24MNN+adGznS1tdVo4QPsIqVs0mbolHV/zkOEXQC9gUS3aj/bD4g 7WYg== X-Gm-Message-State: APjAAAWER6BKCZvdj+HWl0wt0AKCk1yitc84aXD3+p7o8yCna3e+1pLg 0WGt2CKw9JbRv1MAYQA80DQHvR4cDJ2G8dqPT0Y9Fdw= X-Google-Smtp-Source: APXvYqwL6IFML+zrjdQK7IW/RZE/02MGaVUY6QvWbPQ82UI2M9x1+vtoEvNL6jh1LcwaG+pUDAaOEKhWjnau6GIpZkc= X-Received: by 2002:a25:5ca:: with SMTP id 193mr16383919ybf.388.1567283640294; Sat, 31 Aug 2019 13:34:00 -0700 (PDT) MIME-Version: 1.0 From: shreyank amartya Date: Sun, 1 Sep 2019 02:03:48 +0530 Message-ID: Subject: hwpmc NMI/cpuxx ... going to debugger To: freebsd-drivers@freebsd.org Cc: freebsd-hackers@freebsd.org, avg@freebsd.org, mmacy@freebsd.org X-Rspamd-Queue-Id: 46LSk21KCwz3N0K X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=k1FhwzuN; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of shreyankfbsd@gmail.com designates 2607:f8b0:4864:20::b36 as permitted sender) smtp.mailfrom=shreyankfbsd@gmail.com X-Spamd-Result: default: False [-3.99 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36]; FREEMAIL_FROM(0.00)[gmail.com]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; TO_DN_NONE(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; IP_SCORE_FREEMAIL(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; IP_SCORE(0.00)[ip: (-9.45), ipnet: 2607:f8b0::/32(-2.83), asn: 15169(-2.31), country: US(-0.05)]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; RCVD_IN_DNSWL_NONE(0.00)[6.3.b.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; NEURAL_HAM_SHORT(-0.99)[-0.994,0]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com.dwl.dnswl.org : 127.0.5.0] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: freebsd-drivers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Writing device drivers for FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 31 Aug 2019 20:34:03 -0000 Hi, I'm trying to profile a java application using hwpmc. While running the profiler I run into these errors: NMI ISA 30, EISA ff NMI/cpu123 ... going to debugger NMI ISA 30, EISA ff NMI/cpu58 ... going to debugger NMI ISA 20, EISA ff NMI/cpu59 ... going to debugger Due to this, pmclog contains very few samples and sometimes none at all. I enabled hwpmc kernel traces and with that it seems that cpu which is unable to catch the pmc interrupt hits true for this condition in amd_intr(hwpmc_amd.c): if ((pm = pac->pc_amdpmcs[i].phw_pmc) == NULL || !PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) { isnull++; continue; } if (!AMD_PMC_HAS_OVERFLOWED(i)) { ovrflw++; continue; } These are some logs Aug 31 20:01:11 amd kernel: cpu245 MDP:INT:1: cpu=245 tf=0xfffffe00015cbf30 um=0 Aug 31 20:01:11 amd kernel: cpu245 MDP:INT:2: retval=1 isnull=0 ovrflw=0 Aug 31 20:01:11 amd kernel: cpu245 MDP:INT:1: cpu=245 tf=0xfffffe00015cbf30 um=1 Aug 31 20:01:11 amd kernel: cpu245 MDP:INT:2: retval=1 isnull=0 ovrflw=0 Aug 31 20:01:11 amd kernel: cpu245 MDP:INT:1: cpu=245 tf=0xfffffe00015cbf30 um=0 Aug 31 20:01:11 amd kernel: cpu245 MDP:INT:2: retval=0 isnull=16 ovrflw=0 Aug 31 20:01:11 amd kernel: NMI ISA 3c, EISA ff Aug 31 20:01:11 amd kernel: NMI/cpu245 ... going to debugger Aug 31 20:01:11 amd kernel: cpu236 MDP:INT:1: cpu=236 tf=0xfffffe0001595f30 um=0 Aug 31 20:01:11 amd kernel: cpu236 MDP:INT:2: retval=1 isnull=0 ovrflw=0 Aug 31 20:01:11 amd kernel: cpu252 MDP:INT:1: cpu=252 tf=0xfffffe00015f5f30 um=0 Aug 31 20:01:11 amd kernel: cpu252 MDP:INT:2: retval=1 isnull=0 ovrflw=0 Other observations: If I enable all the md=* flags, I do not see this issue. When i run the profiler for a C++ application, I do not encounter this problem. There is no panic observed. Any idea on what could be causing this? or pointers on how to debug this further? Thanks Shreyank