From owner-svn-src-all@FreeBSD.ORG Wed Oct 27 16:07:40 2010 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E1BD71065672; Wed, 27 Oct 2010 16:07:40 +0000 (UTC) (envelope-from yanegomi@gmail.com) Received: from mail-ww0-f50.google.com (mail-ww0-f50.google.com [74.125.82.50]) by mx1.freebsd.org (Postfix) with ESMTP id CBD1B8FC17; Wed, 27 Oct 2010 16:07:39 +0000 (UTC) Received: by wwb24 with SMTP id 24so810113wwb.31 for ; Wed, 27 Oct 2010 09:07:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:sender:received :in-reply-to:references:date:x-google-sender-auth:message-id:subject :from:to:cc:content-type; bh=FRJU5r/w71R+p4m6cqsd6pehK7dikrCOFdDZmh1qLoY=; b=bRyKNxuk0kUbkV+iTFsBBvk8c7mr0eZt9fEI5KZZ8zutZOwwcEstGJqopyD73nZm/z NmjU8uxPmh6qc3kHaBMnPsfCjQWdsjCfF7i9DdsCXy9QOK53AUU3Nf9FPv973nQnTZY2 glLCCuX3Y3q7MR+G4eQxeSXaVqGqiPSmLxOZQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=BLmk5oGlG/pBJ7jpk7nhdGHWlYugHmo8gSVjpjL0V4gNQZGWb6OcTpCRfmzulrgxPf 9VTgW3bF7BaKxBGHZiRCcwDWFv97fKh3Mv4qemSoIQFOwfB0jQggW8pDlDC/5x8wJ2Jp 048/9KmmQIGP5snmpXd+vkNhA+mR839edSHGM= MIME-Version: 1.0 Received: by 10.216.23.147 with SMTP id v19mr1054195wev.58.1288195658264; Wed, 27 Oct 2010 09:07:38 -0700 (PDT) Sender: yanegomi@gmail.com Received: by 10.216.10.198 with HTTP; Wed, 27 Oct 2010 09:07:37 -0700 (PDT) In-Reply-To: <20101027133307.GQ2392@deviant.kiev.zoral.com.ua> References: <201010270232.o9R2Wsu3084553@svn.freebsd.org> <4CC803A8.3040602@freebsd.org> <20101027082122.GD1848@garage.freebsd.pl> <4CC85552.2020100@freebsd.org> <20101027133307.GQ2392@deviant.kiev.zoral.com.ua> Date: Wed, 27 Oct 2010 09:07:37 -0700 X-Google-Sender-Auth: mHF7z1HoNYBFVdi1KUJBCbEtzZk Message-ID: From: Garrett Cooper To: Kostik Belousov Content-Type: multipart/mixed; boundary=0016364d1f159cc03b04939b6ccb Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Pawel Jakub Dawidek , David Xu Subject: Re: svn commit: r214409 - head/sys/kern X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Oct 2010 16:07:41 -0000 --0016364d1f159cc03b04939b6ccb Content-Type: text/plain; charset=ISO-8859-1 On Wed, Oct 27, 2010 at 6:33 AM, Kostik Belousov wrote: > On Wed, Oct 27, 2010 at 04:37:38PM +0000, David Xu wrote: >> Pawel Jakub Dawidek wrote: >> >On Wed, Oct 27, 2010 at 10:49:12AM +0000, David Xu wrote: >> >>I really hate to see such a problem that userland can not figure out >> >>what kernel is using, I try hardly to guess, but still can not find >> >>what it is using. yes, I think the doc may need to be fixed or >> >>another syscall is needed. >> > >> >Maybe you could just add sysctl and eventually put it into sysconf(3)? >> > >> >> I just found a dirty method, use sizeof(long) and kern.smp.maxcpus >> 32 to figure out the size the kernel is using, because it is how >> cpuset_t is constructed, wish it will never be changed. ;-) >> > I think that sysctl is the way forward, but you may add non-portable > FreeBSD function to get the value, and use an ELF aux vector interface > to avoid sysctl most of the time. How about this patch? I implemented this as a readonly tunable and sysconf tunable, because (AFAIK) the value that is being tested shouldn't change during runtime after the system has been booted up, and figuring that the value wasn't going to change it was better to lose 4/8 bytes on the kernel stack instead of having to recompute the value every time in a function call, with the associated lost heap / stack memory in the process, as the assumption is that this libcall was going to be called frequently by some programs. Thanks! -Garrett --0016364d1f159cc03b04939b6ccb Content-Type: text/x-patch; charset=US-ASCII; name="cpuset_t-size-sysctl-and-sysconf-value.patch" Content-Disposition: attachment; filename="cpuset_t-size-sysctl-and-sysconf-value.patch" Content-Transfer-Encoding: base64 X-Attachment-Id: f_gfseer440 SW5kZXg6IGluY2x1ZGUvdW5pc3RkLmgKPT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PQotLS0gaW5jbHVkZS91bmlzdGQuaAko cmV2aXNpb24gMjE0NDEzKQorKysgaW5jbHVkZS91bmlzdGQuaAkod29ya2luZyBjb3B5KQpAQCAt Mjg4LDYgKzI4OCw3IEBACiAjaWYgX19CU0RfVklTSUJMRQogI2RlZmluZQlfU0NfTlBST0NFU1NP UlNfQ09ORgk1NwogI2RlZmluZQlfU0NfTlBST0NFU1NPUlNfT05MTgk1OAorI2RlZmluZQlfU0Nf Q1BVU0VUX1NJWkUJCTEyMgogI2VuZGlmCiAKIC8qIEV4dGVuc2lvbnMgZm91bmQgaW4gU29sYXJp cyBhbmQgTGludXguICovCkluZGV4OiBsaWIvbGliYy9nZW4vc3lzY29uZi5jCj09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0K LS0tIGxpYi9saWJjL2dlbi9zeXNjb25mLmMJKHJldmlzaW9uIDIxNDQxMykKKysrIGxpYi9saWJj L2dlbi9zeXNjb25mLmMJKHdvcmtpbmcgY29weSkKQEAgLTU5Nyw2ICs1OTcsMTUgQEAKIAkJcmV0 dXJuIChsdmFsdWUpOwogI2VuZGlmCiAKKyNpZmRlZiBfU0NfQ1BVU0VUX1NJWkUKKwljYXNlIF9T Q19DUFVTRVRfU0laRToKKwkJbGVuID0gc2l6ZW9mKGx2YWx1ZSk7CisJCWlmIChzeXNjdGxieW5h bWUoImtlcm4uc2NoZWQuY3B1c2V0c2l6ZSIsICZsdmFsdWUsICZsZW4sIE5VTEwsCisJCSAgICAw KSA9PSAtMSkKKwkJCXJldHVybiAoLTEpOworCQlyZXR1cm4gKGx2YWx1ZSk7CisjZW5kaWYKKwog CWRlZmF1bHQ6CiAJCWVycm5vID0gRUlOVkFMOwogCQlyZXR1cm4gKC0xKTsKSW5kZXg6IHN5cy9r ZXJuL3NjaGVkX3VsZS5jCj09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT0KLS0tIHN5cy9rZXJuL3NjaGVkX3VsZS5jCShyZXZp c2lvbiAyMTQ0MTMpCisrKyBzeXMva2Vybi9zY2hlZF91bGUuYwkod29ya2luZyBjb3B5KQpAQCAt MjcxMiw2ICsyNzEyLDggQEAKIAlzYnVmX2RlbGV0ZSh0b3BvKTsKIAlyZXR1cm4gKGVycik7CiB9 CisKK3N0YXRpYyBzaXplX3QgX2tlcm5fY3B1c2V0X3NpemUgPSBzaXplb2YoY3B1c2V0X3QpOwog I2VuZGlmCiAKIFNZU0NUTF9OT0RFKF9rZXJuLCBPSURfQVVUTywgc2NoZWQsIENUTEZMQUdfUlcs IDAsICJTY2hlZHVsZXIiKTsKQEAgLTI3NDgsNiArMjc1MCwxNSBAQAogU1lTQ1RMX1BST0MoX2tl cm5fc2NoZWQsIE9JRF9BVVRPLCB0b3BvbG9neV9zcGVjLCBDVExUWVBFX1NUUklORyB8CiAgICAg Q1RMRkxBR19SRCwgTlVMTCwgMCwgc3lzY3RsX2tlcm5fc2NoZWRfdG9wb2xvZ3lfc3BlYywgIkEi LCAKICAgICAiWE1MIGR1bXAgb2YgZGV0ZWN0ZWQgQ1BVIHRvcG9sb2d5Iik7CisKKy8qIAorICog UmV0dXJuIHRoZSBzaXplIG9mIGNwdXNldF90IGF0IHRoZSBrZXJuZWwgbGV2ZWwKKyAqCisgKiBY WFggKGdjb29wZXIpOiByZXBsYWNlIFVMT05HIHdpdGggU0laRSBvbmNlIENUTFRZUEVfU0laRSBp cyBpbXBsZW1lbnRlZC4KKyAqLworU1lTQ1RMX1VMT05HKF9rZXJuX3NjaGVkLCBPSURfQVVUTywg Y3B1c2V0c2l6ZSwgQ1RMRkxBR19SRFRVTiwKKyAgICAmX2tlcm5fY3B1c2V0X3NpemUsIDAsICJL ZXJuZWwtbGV2ZWwgY3B1c2V0X3Qgc3RydWN0IHNpemUiKTsKKwogI2VuZGlmCiAKIC8qIHBzIGNv bXBhdC4gIEFsbCBjcHUgcGVyY2VudGFnZXMgZnJvbSBVTEUgYXJlIHdlaWdodGVkLiAqLwo= --0016364d1f159cc03b04939b6ccb--