linux-kernel - Re: [PATCH v8 24/24] nvme-pci: optimize single-segment handling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CA+1E3r+9kEs-fqND-VD+y6FWfiGqr1vN8M0GufD3oHdwLdFcrQ@mail.gmail.com>
Date: Fri, 18 Apr 2025 18:02:08 +0530
From: Kanchan Joshi <joshiiitr@...il.com>
To: Damien Le Moal <dlemoal@...nel.org>
Cc: Leon Romanovsky <leon@...nel.org>, Marek Szyprowski <m.szyprowski@...sung.com>, 
	Jens Axboe <axboe@...nel.dk>, Christoph Hellwig <hch@....de>, Keith Busch <kbusch@...nel.org>, 
	Kanchan Joshi <joshi.k@...sung.com>, Jake Edge <jake@....net>, Jonathan Corbet <corbet@....net>, 
	Jason Gunthorpe <jgg@...pe.ca>, Zhu Yanjun <zyjzyj2000@...il.com>, Robin Murphy <robin.murphy@....com>, 
	Joerg Roedel <joro@...tes.org>, Will Deacon <will@...nel.org>, Sagi Grimberg <sagi@...mberg.me>, 
	Bjorn Helgaas <bhelgaas@...gle.com>, Logan Gunthorpe <logang@...tatee.com>, 
	Yishai Hadas <yishaih@...dia.com>, 
	Shameer Kolothum <shameerali.kolothum.thodi@...wei.com>, Kevin Tian <kevin.tian@...el.com>, 
	Alex Williamson <alex.williamson@...hat.com>, Jérôme Glisse <jglisse@...hat.com>, 
	Andrew Morton <akpm@...ux-foundation.org>, linux-doc@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-block@...r.kernel.org, 
	linux-rdma@...r.kernel.org, iommu@...ts.linux.dev, 
	linux-nvme@...ts.infradead.org, linux-pci@...r.kernel.org, 
	kvm@...r.kernel.org, linux-mm@...ck.org, 
	Niklas Schnelle <schnelle@...ux.ibm.com>, Chuck Lever <chuck.lever@...cle.com>, 
	Luis Chamberlain <mcgrof@...nel.org>, Matthew Wilcox <willy@...radead.org>, 
	Dan Williams <dan.j.williams@...el.com>, Chaitanya Kulkarni <kch@...dia.com>, 
	Nitesh Shetty <nj.shetty@...sung.com>, Leon Romanovsky <leonro@...dia.com>, vishak.g@...sung.com
Subject: Re: [PATCH v8 24/24] nvme-pci: optimize single-segment handling

> > +     if (nr_segments == 1 && (iod->flags & IOD_SINGLE_SEGMENT)) {
>
> nvme_pci_setup_prps() calls nvme_try_setup_prp_simple() which sets
> IOD_SINGLE_SEGMENT if and only if the req has a single phys segment. So why do
> you need to count the segments again here ? Looking at the flag only should be
> enough, no ?

Yes, the flag will be enough.
I started with nr_segments first, but felt the need of a flag when I
reached to handle the unmap part.

This can be changed if the series requires an iteration.
Or I can do this as part of the cleanup which I anyway need to do to
replace the "iod->aborted" field with a flag.

-- 
Kanchan