From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH RFC 3/4] barriers: convert a control to a data dependency Date: Mon, 7 Jan 2019 08:36:36 -0500 Message-ID: <20190107082223-mutt-send-email-mst@kernel.org> References: <20190102205715.14054-1-mst@redhat.com> <20190102205715.14054-4-mst@redhat.com> <86023cbe-d1ae-a0d6-7b75-26556f1a0c1f@redhat.com> <20190106231756-mutt-send-email-mst@kernel.org> <20190107094610.GA2861@worktop.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Cc: Andrea Parri , linux-doc@vger.kernel.org, Akira Yokosawa , Will Deacon , virtualization@lists.linux-foundation.org, David Howells , linux-arch@vger.kernel.org, Jonathan Corbet , linux-sparse@vger.kernel.org, Alan Stern , Matt Turner , "Paul E. McKenney" , Boqun Feng , Arnd Bergmann , Daniel Lustig , Nicholas Piggin , Ivan Kokshaysky , Luc Maranget , Richard Henderson , Jade Alglave , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, Luc Van Oostenryck To: Peter Zijlstra Return-path: Content-Disposition: inline In-Reply-To: <20190107094610.GA2861@worktop.programming.kicks-ass.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org T24gTW9uLCBKYW4gMDcsIDIwMTkgYXQgMTA6NDY6MTBBTSArMDEwMCwgUGV0ZXIgWmlqbHN0cmEg d3JvdGU6Cj4gT24gU3VuLCBKYW4gMDYsIDIwMTkgYXQgMTE6MjM6MDdQTSAtMDUwMCwgTWljaGFl bCBTLiBUc2lya2luIHdyb3RlOgo+ID4gT24gTW9uLCBKYW4gMDcsIDIwMTkgYXQgMTE6NTg6MjNB TSArMDgwMCwgSmFzb24gV2FuZyB3cm90ZToKPiA+ID4gT24gMjAxOS8xLzMg5LiK5Y2INDo1Nywg TWljaGFlbCBTLiBUc2lya2luIHdyb3RlOgo+IAo+ID4gPiA+ICsjaWYgZGVmaW5lZChDT01QSUxF Ul9IQVNfT1BUSU1JWkVSX0hJREVfVkFSKSAmJiBcCj4gPiA+ID4gKwkhZGVmaW5lZChBUkNIX05F RURTX1JFQURfQkFSUklFUl9ERVBFTkRTKQo+ID4gPiA+ICsKPiA+ID4gPiArI2RlZmluZSBkZXBl bmRlbnRfcHRyX21iKHB0ciwgdmFsKSAoewkJCQkJXAo+ID4gPiA+ICsJbG9uZyBkZXBlbmRlbnRf cHRyX21iX3ZhbCA9IChsb25nKSh2YWwpOwkJCVwKPiA+ID4gPiArCWxvbmcgZGVwZW5kZW50X3B0 cl9tYl9wdHIgPSAobG9uZykocHRyKSAtIGRlcGVuZGVudF9wdHJfbWJfdmFsOwlcCj4gPiA+ID4g KwkJCQkJCQkJCVwKPiA+ID4gPiArCUJVSUxEX0JVR19PTihzaXplb2YodmFsKSA+IHNpemVvZihs b25nKSk7CQkJXAo+ID4gPiA+ICsJT1BUSU1JWkVSX0hJREVfVkFSKGRlcGVuZGVudF9wdHJfbWJf dmFsKTsJCQlcCj4gPiA+ID4gKwkodHlwZW9mKHB0cikpKGRlcGVuZGVudF9wdHJfbWJfcHRyICsg ZGVwZW5kZW50X3B0cl9tYl92YWwpOwlcCj4gPiA+ID4gK30pCj4gPiA+ID4gKwo+ID4gPiA+ICsj ZWxzZQo+ID4gPiA+ICsKPiA+ID4gPiArI2RlZmluZSBkZXBlbmRlbnRfcHRyX21iKHB0ciwgdmFs KSAoeyBtYigpOyAocHRyKTsgfSkKPiA+ID4gCj4gPiA+IAo+ID4gPiBTbyBmb3IgdGhlIGV4YW1w bGUgb2YgcGF0Y2ggNCwgd2UnZCBiZXR0ZXIgZmFsbCBiYWNrIHRvIHJtYigpIG9yIG5lZWQgYQo+ ID4gPiBkZXBlbmRlbnRfcHRyX3JtYigpPwo+ID4gPiAKPiA+ID4gVGhhbmtzCj4gPiAKPiA+IFlv dSBtZWFuIGZvciBzdHJvbmdseSBvcmRlcmVkIGFyY2hpdGVjdHVyZXMgbGlrZSBJbnRlbD8KPiA+ IFllcywgbWF5YmUgaXQgbWFrZXMgc2Vuc2UgdG8gaGF2ZSBkZXBlbmRlbnRfcHRyX3NtcF9ybWIs Cj4gPiBkZXBlbmRlbnRfcHRyX2RtYV9ybWIgYW5kIGRlcGVuZGVudF9wdHJfdmlydF9ybWIuCj4g PiAKPiA+IG1iIHZhcmlhbnQgaXMgdW51c2VkIHJpZ2h0IG5vdyBzbyBJJ2xsIHJlbW92ZSBpdC4K PiAKPiBIb3cgYWJvdXQgbmFtaW5nIHRoZSB0aGluZzogZGVwZW5kZW50X3B0cigpID8gVGhhdCBp cyB3aXRob3V0IGFueSAociltYgo+IGltcGxpY2F0aW9ucyBhdCBhbGwuIFRoZSBhZGRyZXNzIGRl cGVuZGVuY3kgaXMgc3RyaWN0bHkgd2Vha2VyIHRoYW4gYW4KPiBybWIgaW4gdGhhdCBpdCB3aWxs IG9ubHkgb3JkZXIgdGhlIHR3byBsb2FkcyBpbiBxZXN0aW9uIGFuZCBub3QsIGxpa2UKPiBybWIs IGFueSBwcmlvciB0byBhbnkgbGF0ZXIgbG9hZC4KClNvIEknbSBmaW5lIHdpdGggdGhpcyBhcyBp dCdzIGVub3VnaCBmb3IgdmlydGlvLCBidXQgSSB3b3VsZCBsaWtlIHRvIHBvaW50IG91dCB0d28g dGhpbmdzOgoKMS4gRS5nLiBvbiB4ODYgYm90aCBTTVAgYW5kIERNQSB2YXJpYW50cyBjYW4gYmUg Tk9QcyBidXQKdGhlIG1hZGF0b3J5IG9uZSBjYW4ndCwgc28gYXNzdW1pbmcgd2UgZG8gbm90IHdh bnQKaXQgdG8gYmUgc3Ryb25nZXIgdGhhbiBybXAgdGhlbiBlaXRoZXIgd2Ugd2FudApzbXBfZGVw ZW5kZW50X3B0cigpLCBkbWFfZGVwZW5kZW50X3B0cigpLCBkZXBlbmRlbnRfcHRyKCkKb3Igd2Ug anVzdCB3aWxsIHNwZWNpZnkgdGhhdCBkZXBlbmRlbnRfcHRyKCkgd29ya3MgZm9yCmJvdGggRE1B IGFuZCBTTVAuCgoyLiBEb3duIHRoZSByb2FkLCBzb21lb25lIG1pZ2h0IHdhbnQgdG8gb3JkZXIg YSBzdG9yZSBhZnRlciBhIGxvYWQuCkFkZHJlc3MgZGVwZW5kZW5jeSBkb2VzIHRoYXQgZm9yIHVz IHRvby4gQXNzdW1pbmcgd2UgbWFrZQpkZXBlbmRlbnRfcHRyIGEgTk9QIG9uIHg4Niwgd2Ugd2ls bCB3YW50IGFuIG1iIHZhcmlhbnQKd2hpY2ggaXNuJ3QgYSBOT1Agb24geDg2LiBXaWxsIHdlIHdh bnQgdG8gcmVuYW1lCmRlcGVuZGVudF9wdHIgdG8gZGVwZW5kZW50X3B0cl9ybWIgYXQgdGhhdCBw b2ludD8KClRoYW5rcywKCi0tIApNU1QKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX18KVmlydHVhbGl6YXRpb24gbWFpbGluZyBsaXN0ClZpcnR1YWxpemF0aW9u QGxpc3RzLmxpbnV4LWZvdW5kYXRpb24ub3JnCmh0dHBzOi8vbGlzdHMubGludXhmb3VuZGF0aW9u Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL3ZpcnR1YWxpemF0aW9u