From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nai Xia Subject: Re: Is this a racing bug in page_make_sharable()? Date: Thu, 27 Dec 2012 23:35:27 +0800 Message-ID: <50DC6ABF.7020003@gmail.com> References: <4F14345B.4040807@gmail.com> <20120117105323.GA74654@ocelot.phlegethon.org> Reply-To: nai.xia@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; Format="flowed" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20120117105323.GA74654@ocelot.phlegethon.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Tim Deegan Cc: Lixiuchang , Xiaowei Yang , "Luohao (brian)" , xen-devel@lists.xensource.com, Grzegorz Milos List-Id: xen-devel@lists.xenproject.org SGkgYWxsLAoKTGFzdCB0aW1lIEkgcmVwb3J0ZWQgdGhpcyBidWcuIEFuZCBJIG5vdyBzZWUgc29t ZSBjaGFuZ2VzIGluIHlvdXIgWGVuCmdpdCBtYXN0ZXIgYnJhbmNoLgpIb3dldmVyLCBJIHRoaW5r IHRoZSBwcm9ibGVtIHN0aWxsIHJlbWFpbnMgZm9yIHJlZi1jaGVja2luZyBpbiBwYWdlCm1pZ3Jh dGlvbiB0byBkb21fY293LgoKSSB0aGluayBJIGNhbiBjb25zdHJ1Y3QgYSBidWcgYnkgaW50ZXJs ZWF2aW5nIHRoZSB0d28gY29kZSBwYXRoczoKCmluIGd1ZXN0X3JlbW92ZV9wYWdlKCkgICAgICAg ICAgICAgIHwgICAgICAgICAgICAgIGluIHBhZ2VfbWFrZV9zaGFyYWJsZSgpCi0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LQppZiAoIHAybV9pc19zaGFyZWQocDJtdCkgKSAgICAgICAgICAgICAgICAgICAgICAgLi4uLi4K Li4uICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIC4uLi4uCnBh Z2UgPSBtZm5fdG9fcGFnZShtZm4pOyAgICAgICAgICAgICAgICAgICAgICAgICAuLi4uLgogICAg ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIC4uLi4uCgogICAg ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIGlmICggIWdldF9w YWdlX2FuZF90eXBlKHBhZ2UsIGQsIFBHVF9zaGFyZWRfcGFnZSkgKSAgICAvLyBzdWNjZXNzCgog ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIC4uLi4uLi4u LgogICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIGlmICgg cGFnZS0+Y291bnRfaW5mbyAhPSAoUEdDX2FsbG9jYXRlZCB8ICgyICsgZXhwZWN0ZWRfcmVmY250 KSkgKSAvLyBhbHNvIHBhc3MKCgppZiAoIHVubGlrZWx5KCFnZXRfcGFnZShwYWdlLCBkKSkgKQoK LyogZ28gb24gdG8gcmVtb3ZlIHBhZ2UgKi8gICAgICAgICAgICAgICAgICAgICAgIC8qIGdvIG9u IHRvIGFkZCBwYWdlIHRvIGNvdyBkb21haW4gKi8KLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLQoKCmlzIHRo ZXJlIGFueXRoaW5nIHRoYXQgY2FuIGFscmVhZHkgcHJldmVudCBzdWNoIHJhY2luZyBvciBpcyB0 aGlzIHJlYWxseSBjYW4gaGFwcGVuPwoKClRoYW5rcywKCk5haSBYaWEKCgpPbiAyMDEy5bm0MDHm nIgxN+aXpSAxODo1MywgVGltIERlZWdhbiB3cm90ZToKPiBBdCAyMjo0MyArMDgwMCBvbiAxNiBK YW4gKDEzMjY3NTM4MzQpLCBOYWkgWGlhIHdyb3RlOgo+PiBIaSBHcnplZ29yeiwKPj4KPj4gQXMg SSB1bmRlcnN0YW5kLCB0aGUgcHVycG9zZSBvZiB0aGUgY29kZSBpbiBwYWdlX21ha2Vfc2hhcmFi bGUoKQo+PiBjaGVja2luZyB0aGUgcmVmIGNvdW50IGlzIHRvIGVuc3VyZSB0aGF0IG5vYm9keSB1 bmV4cGVjdGVkIGlzIHdvcmtpbmcKPj4gb24gdGhlIHBhZ2UsIGFuZCBzbyB3ZSBjYW4gbWlncmF0 ZSBpdCB0byBkb21fY293LCByaWdodD8KPj4KPj4gPT09PQo+PiAgICAgIC8qIENoZWNrIGlmIHRo ZSByZWYgY291bnQgaXMgMi4gVGhlIGZpcnN0IGZyb20gUEdUX2FsbG9jYXRlZCwgYW5kCj4+ICAg ICAgICogdGhlIHNlY29uZCBmcm9tIGdldF9wYWdlX2FuZF90eXBlIGF0IHRoZSB0b3Agb2YgdGhp cyBmdW5jdGlvbiAqLwo+PiAgICAgIGlmKHBhZ2UtPmNvdW50X2luZm8gIT0gKFBHQ19hbGxvY2F0 ZWQgfCAoMiArIGV4cGVjdGVkX3JlZmNudCkpKQo+PiAgICAgIHsKPj4gICAgICAgICAgLyogUmV0 dXJuIHR5cGUgY291bnQgYmFjayB0byB6ZXJvICovCj4+ICAgICAgICAgIHB1dF9wYWdlX2FuZF90 eXBlKHBhZ2UpOwo+PiAgICAgICAgICBzcGluX3VubG9jaygmZC0+cGFnZV9hbGxvY19sb2NrKTsK Pj4gICAgICAgICAgcmV0dXJuIC1FMkJJRzsKPj4gICAgICB9Cj4+ID09PT0KPj4KPj4gSG93ZXZl ciwgaXQgc2VlbXMgdG8gbWUgdGhhdCB0aGlzIHJlZiBjaGVjayBhbmQgdGhlIGZvbGxvd2luZyBw YWdlCj4+IG1pZ3JhdGlvbiBpcyBub3QgYXRvbWljKCBhbHRob3VnaCB0aGUgb3BlcmF0aW9ucyBm b3IgdHlwZV9pbmZvIHJlZgo+PiBjaGVjayBzZWVtcyBnb29kKSBpLmUuIGl0J3MgcG9zc2libGUg dGhhdCBpdCBwYXNzZWQgdGhpcyByZWYKPj4gY2hlY2sgYnV0IGp1c3QgYmVmb3JlIGl0IGdvZXMg dG8gZG9tX2Nvdywgc29tZW9uZSBlbHNlIGdldHMgdGhpcyBwYWdlPwo+Cj4gWWVzLCB0aGVyZSBh cmUgYSBudW1iZXIgb2YgcmFjZXMgYXJvdW5kIHRoZSBwMm0gY29kZTsgQW5kZXJzCj4gTGFnYXIt Q2F2aWxsYSBoYXMgYmVlbiB3b3JraW5nIG9uIGZpeGluZyB0aGUgbG9ja2luZyBhcm91bmQgcDJt IGxvb2t1cHMKPiB0byB0YWtlIGNhcmUgb2YgdGhpcy4KPgo+IFRpbS4KPgoKX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVsIG1haWxpbmcgbGlz dApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwOi8vbGlzdHMueGVuLm9yZy94ZW4tZGV2ZWwK