Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758279Ab3GZCJ6 (ORCPT ); Thu, 25 Jul 2013 22:09:58 -0400 Received: from merlin.infradead.org ([205.233.59.134]:53665 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756954Ab3GZCJz (ORCPT ); Thu, 25 Jul 2013 22:09:55 -0400 Date: Thu, 25 Jul 2013 20:09:28 -0600 From: Jens Axboe To: "Nicholas A. Bellinger" Cc: Alexander Gordeev , James Bottomley , Mike Christie , Tejun Heo , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Jeff Garzik , linux-scsi Subject: Re: [PATCH RESEND 0/1] AHCI: Optimize interrupt processing Message-ID: <20130726020928.GL29296@kernel.dk> References: <20130719003034.GG28005@kernel.dk> <1374195825.7397.997.camel@haakon3.risingtidesystems.com> <1374215660.7397.1041.camel@haakon3.risingtidesystems.com> <1374248000.2266.20.camel@dabdike> <1374267684.7397.1058.camel@haakon3.risingtidesystems.com> <1374296162.7397.1098.camel@haakon3.risingtidesystems.com> <20130722150359.GA16564@dhcp-26-207.brq.redhat.com> <1374527436.7397.1145.camel@haakon3.risingtidesystems.com> <20130725101641.GB31994@dhcp-26-207.brq.redhat.com> <1374790082.7397.1411.camel@haakon3.risingtidesystems.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1374790082.7397.1411.camel@haakon3.risingtidesystems.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1527 Lines: 39 On Thu, Jul 25 2013, Nicholas A. Bellinger wrote: > On Thu, 2013-07-25 at 12:16 +0200, Alexander Gordeev wrote: > > On Mon, Jul 22, 2013 at 02:10:36PM -0700, Nicholas A. Bellinger wrote: > > > Np. FYI, you'll want to use the latest commit e7827b351 HEAD from > > > target-pending/scsi-mq, which now has functioning scsi-generic support. > > > > Survives a boot, a kernel build and the build's result :) > > Great. Thanks for the feedback Alexander! > > So the next step on my end is to enable -mq for ahci, and verify initial > correctness using QEMU/KVM hardware emulation. > > Btw, I've been looking at enabling the SHT->cmd_size for struct > ata_queued_cmd descriptor pre-allocation, but AFAICT these descriptors > are already all pre-allocated by libata and obtained via ata_qc_new() -> > __ata_qc_from_tag() during ata_scsi_queuecmd(). Might still not be a bad idea to do it: - Cleans up a driver, getting rid of the need to alloc, maintain, and free those structures. - Should be some cache locality benefits to having it all sequential. > So that said, with the struct request + struct scsi_cmnd pre-allocations > already provided by blk-mq -> scsi-mq code, all memory allocations > should have already been eliminated from I/O fast path. Nice! -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/