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charset=us-ascii Content-Disposition: inline In-Reply-To: <20220706065127.GA27132@lst.de> ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1657091086; a=rsa-sha256; cv=none; b=3ZhhY9qQcYjMBoBZuYL76Ej/tQne2gv6pNta+ovhEoL5V46dwMBMqV81aGqWnXFkbI1ASB gE8ZpB8OKgbXiszZJDmoOhGeqgIu7I3koNid/KbZqwNr0U2h7RCaND19TBLbuxrOfjtPTI kUUT9bQXfuJYJVq+j32qoRMlGk5mShY= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=jvQpbiTH; spf=pass (imf06.hostedemail.com: domain of gregkh@linuxfoundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org; dmarc=pass (policy=none) header.from=linuxfoundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1657091086; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=1gje+7JJywl8z+hojDQ/CdCFHPcNXeAmo9Z1tbQVDz0=; b=8SH2n2ZFrTR959YqtKR5zWMXqR4KUXjQXoBmK038IRulnlWHVItu9FZwRmrZMx9h+o3UTS SJwDK1wnTvnpFypDMgzhQ6/oFylzKO2TpRdt2Z25bT/4ocHAw7gu6TOQbQfaMZmzIAB+be EFF15ay5z1qzFYf1sxvwKri3l+0/anM= X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 83620180006 X-Rspam-User: Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=jvQpbiTH; spf=pass (imf06.hostedemail.com: domain of gregkh@linuxfoundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org; dmarc=pass (policy=none) header.from=linuxfoundation.org X-Stat-Signature: dxzhqahepxzd6uiftzbjph4gefyq6men X-HE-Tag: 1657091086-322374 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Jul 06, 2022 at 08:51:27AM +0200, Christoph Hellwig wrote: > On Tue, Jul 05, 2022 at 12:16:45PM -0600, Logan Gunthorpe wrote: > > The current version does it through a char device, but that requires > > creating a simple_fs and anon_inode for teardown on driver removal, plus > > a bunch of hooks through the driver that exposes it (NVMe, in this case) > > to set this all up. > > > > Christoph is suggesting a sysfs interface which could potentially avoid > > the anon_inode and all of the extra hooks. It has some significant > > benefits and maybe some small downsides, but I wouldn't describe it as > > horrid. > > Yeah, I don't think is is horrible, it fits in with the resource files > for the BARs, and solves a lot of problems. Greg, can you explain > what would be so bad about it? As you mention, you will have to pass different things down into sysfs in order for that to be possible. If it matches the resource files like we currently have today, that might not be that bad, but it still feels odd to me. Let's see an implementation and a Documentation/ABI/ entry first though. thanks, greg k-h