From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id mBGNEg2o023124 for ; Tue, 16 Dec 2008 17:14:42 -0600 Date: Wed, 17 Dec 2008 10:14:11 +1100 From: Dave Chinner Subject: Re: 12x performance drop on md/linux+sw raid1 due to barriers [xfs] Message-ID: <20081216231411.GG32301@disturbed> References: <18757.33373.744917.457587@tree.ty.sabi.co.uk> <20081215223857.GF32301@disturbed> <200812161039.07700.Martin@lichtvoll.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <200812161039.07700.Martin@lichtvoll.de> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Martin Steigerwald Cc: linux-xfs@oss.sgi.com, Linux RAID Linux XFS T24gVHVlLCBEZWMgMTYsIDIwMDggYXQgMTA6Mzk6MDdBTSArMDEwMCwgTWFydGluIFN0ZWlnZXJ3 YWxkIHdyb3RlOgo+IEFtIE1vbnRhZyAxNSBEZXplbWJlciAyMDA4IHNjaHJpZWIgRGF2ZSBDaGlu bmVyOgo+ID4gT24gU3VuLCBEZWMgMTQsIDIwMDggYXQgMTA6MDI6MDVQTSArMDAwMCwgUGV0ZXIg R3JhbmRpIHdyb3RlOgo+ID4gPiBUaGUgcHVycG9zZSBvZiBiYXJyaWVycyBpcyB0byBndWFyYW50 ZWUgdGhhdCByZWxldmFudCBkYXRhIGlzCj4gPiA+IGtub3duIHRvIGJlIG9uIHBlcnNpc3RlbnQg c3RvcmFnZSAoa2luZCBvZiBoYXJkd2FyZSAnZnN5bmMnKS4KPiA+ID4KPiA+ID4gSW4gZWZmZWN0 IHdyaXRlIGJhcnJpZXIgbWVhbnMgInRlbGwgbWUgd2hlbiByZWxldmFudCBkYXRhIGlzIG9uCj4g PiA+IHBlcnNpc3RlbnQgc3RvcmFnZSIsIG9yIGxlc3MgcHJlY2lzZWx5ICJmbHVzaC9zeW5jIHdy aXRlcyBub3cKPiA+ID4gYW5kIHRlbGwgbWUgd2hlbiBpdCBpcyBkb25lIi4gUHJvcGVydGllcyBh cyB0byBvcmRlcmluZyBhcmUganVzdAo+ID4gPiBhIHNpZGUgZWZmZWN0Lgo+ID4KPiA+IE5vLCB0 aGF0IGlzIGluY29ycmVjdC4KPiA+Cj4gPiBCYXJyaWVycyBwcm92aWRlIHN0cm9uZyBvcmRlcmlu ZyBzZW1hbnRpY3MuICBJL09zIGlzc3VlZCBiZWZvcmUgdGhlCj4gPiBiYXJyaWVyIG11c3QgYmUg Y29tcGxldGVkIGJlZm9yZSB0aGUgYmFycmllciBJL08sIGFuZCBJL09zIGlzc3VlZAo+ID4gYWZ0 ZXIgdGhlIGJhcnJpZXIgd3JpdGUgbXVzdCBub3QgYmUgc3RhcnRlZCBiZWZvcmUgdGhlIGJhcnJp ZXIgd3JpdGUKPiA+IGNvbXBsZXRlcy4gVGhlIGVsZXZhdG9ycyBhcmUgbm90IGFsbG93ZWQgdG8g cmUt0L5yZGVyIEkvT3MgYXJvdW5kCj4gPiBiYXJyaWVycy4KPiA+Cj4gPiBUaGlzIGlzIGFsbCBk b2N1bWVudGVkIGluIERvY3VtZW50YXRpb24vYmxvY2svYmFycmllci50eHQuIFBsZWFzZQo+ID4g cmVhZCBpdCBiZWNhdXNlIG1vc3Qgb2Ygd2hhdCB5b3UgYXJlIHNheWluZyBhcHBlYXJzIHRvIGJl IGJhc2VkIG9uCj4gPiBpbmNvcnJlY3QgYXNzdW1wdGlvbnMgYWJvdXQgd2hhdCBiYXJyaWVycyBk by4KPiAKPiBIbW1tLCBzbyBJIGFtIG5vdCBjb21wbGV0ZWx5IG9mZiB0cmFjayBpdCBzZWVtcyA7 LSkuCj4gCj4gV2hhdCBJIHN0aWxsIGRvIG5vdCB1bmRlcnN0YW5kIHRoZW4gaXM6IEhvdyBjYW4g d3JpdGUgYmFycmllcnMgKyB3cml0ZSAKPiBjYWNoZSBiZSBzbG93ZXIgdGhhbiBubyB3cml0ZSBi YXJyaWVycyArIG5vIGNhY2hlPwoKQmVjYXVzZSBmcmVxdWVudCB3cml0ZSBiYXJyaWVycyBjYXVz ZSBvcmRlcmluZyBjb25zdHJhaW50cyBvbiBJL08uCkZvciBleGFtcGxlLCBpbiBYRlMgbG9nIEkv T3MgYXJlIHNlcXVlbnRpYWwuIFdpdGggYmFycmllcnMgZW5hYmxlZAp0aGV5IGNhbm5vdCBiZSBt ZXJnZWQgYnkgdGhlIGVsZXZhdG9yLCB3aGVyZWFzIHdpdGhvdXQgYmFycmllcnMKdGhleSBjYW4g YmUgbWVyZ2VkIGFuZCBpc3N1ZWQgYXMgYSBzaW5nbGUgSS9PLgoKRnVydGhlciwgaWYgeW91IGhh dmUgbm8gYmFycmllciBJL29zIHF1ZXVlZCBpbiB0aGUgZWxldmF0b3IsIHNvcnRpbmcKYW5kIG1l cmdpbmcgb2NjdXJzIGFjcm9zcyB0aGUgZW50aXJlIHF1ZXVlIG9mIEkvT3MsIG5vdCBqdXN0IHRo ZQpJL09zIHRoYXQgaGF2ZSBiZWVuIGlzc3VlZCBhZnRlciB0aGUgbGFzdCBiYXJyaWVyIEkvTy4K CkVmZmVjdGl2ZWx5IHRoZSBvcmRlcmluZyBjb25zdHJhaW50cyBvZiBiYXJyaWVycyBpbnRyb2R1 Y2UgbW9yZQpzZWVrcyBieSByZWR1Y2luZyB0aGUgZWZmaWNpZW5jeSBvZiB0aGUgZWxldmF0b3Ig ZHVlIHRvIGNvbnN0cmFpbmluZwpzb3J0aW5nIGFuZCBtZXJnaW5nIHJhbmdlcy4KCkluIG1hbnkg Y2FzZXMsIHRoZSBvcmRlcmluZyBjb25zdHJhaW50cyBpbXBvc2UgYSBoaWdoZXIgc2VlayBwZW5h bHR5CnRoYW4gdGhlIHdyaXRlIGNhY2hlIGNhbiBtaXRpZ2F0ZSAtIHRoZSB3aG9sZSBwdXJwb3Nl IG9mIHRoZSBiYXJyaWVyCklPcyBpcyB0byBmb3JjZSB0aGUgY2FjaGUgdG8gYmUgZmx1c2hlZCAt IHNvIHdyaXRlIGNhY2hpbmcgZG9lcyBub3QKaW1wcm92ZSBwZXJmb3JtYW5jZSB3aGVuIGZyZXF1 ZW50IGJhcnJpZXJzIGFyZSBpc3N1ZWQuIEluIHRoaXMgY2FzZSwKYmFycmllcnMgYXJlIHRoZSBw cm9ibGVtIGFuZCBoZW5jZSB0dXJuaW5nIG9mIHRoZSBjYWNoZSBhbmQgYmFycmllcnMKd2lsbCBy ZXN1bHQgaW4gaGlnaGVyIHBlcmZvcm1hbmNlLgoKCgo+IEkgc3RpbGwgd291bGQgZXhwZWN0IAo+ IHdyaXRlIGJhcnJpZXJzICsgd3JpdGUgY2FjaGUgYmUgaW4gYmV0d2VlbiBubyBiYXJyaWVycyAr IHdyaXRlIGNhY2hlIGFuZCAKPiBubyBiYXJyaWVycyArIG5vIGNhY2hlIHBlcmZvcm1hbmNlIHdp c2UuCgpEZXBlbmRzIGVudGlyZWx5IG9uIHRoZSBkaXNrIGFuZCB0aGUgd29ya2xvYWQuIFNvbWUg ZGlza3MgYXJlIGZhc3Rlcgp3aXRoIHdjYWNoZSBhbmQgYmFycmllcnMgKGUuZy4gbGFwdG9wIGRy aXZlcyksIHNvbWUgYXJlIGZhc3RlciB3aXRoCm5vIHdjYWNoZSBhbmQgbm8gYmFycmllcnMgKGUu Zy4gc2VydmVyIGRyaXZlcykuLi4uCgo+IEFuZCB3b3VsZCBzZWUgYW55dGhpbmcgZWxzZSBhcyBh IAo+IHJlZ3Jlc3Npb24gYmFzaWNhbGx5LgoKTm8sIGp1c3QgeW91ciB1c3VhbCAicGljayB0aGUg cmlnaHQgaGFyZHdhcmUiIHByb2JsZW0uCgpDaGVlcnMsCgpEYXZlLgotLSAKRGF2ZSBDaGlubmVy CmRhdmlkQGZyb21vcmJpdC5jb20KCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fCnhmcyBtYWlsaW5nIGxpc3QKeGZzQG9zcy5zZ2kuY29tCmh0dHA6Ly9vc3Mu c2dpLmNvbS9tYWlsbWFuL2xpc3RpbmZvL3hmcwo=