linux-kernel - RE: [PATCH v6 kernel 3/5] virtio-balloon: speed up inflate/deflate process

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] [day] [month] [year] [list]

Date:   Sat, 4 Feb 2017 04:35:41 +0000
From:   "Li, Liang Z" <liang.z.li@...el.com>
To:     "Dr. David Alan Gilbert" <dgilbert@...hat.com>
CC:     "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "virtio-dev@...ts.oasis-open.org" <virtio-dev@...ts.oasis-open.org>,
        "qemu-devel@...gnu.org" <qemu-devel@...gnu.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "virtualization@...ts.linux-foundation.org" 
        <virtualization@...ts.linux-foundation.org>,
        "amit.shah@...hat.com" <amit.shah@...hat.com>,
        "Hansen, Dave" <dave.hansen@...el.com>,
        "cornelia.huck@...ibm.com" <cornelia.huck@...ibm.com>,
        "pbonzini@...hat.com" <pbonzini@...hat.com>,
        "mst@...hat.com" <mst@...hat.com>,
        "david@...hat.com" <david@...hat.com>,
        "aarcange@...hat.com" <aarcange@...hat.com>,
        "quintela@...hat.com" <quintela@...hat.com>
Subject: RE: [PATCH v6 kernel 3/5] virtio-balloon: speed up inflate/deflate
 process

> <snip>
> 
> > +static void free_extended_page_bitmap(struct virtio_balloon *vb) {
> > +	int i, bmap_count = vb->nr_page_bmap;
> > +
> > +	for (i = 1; i < bmap_count; i++) {
> > +		kfree(vb->page_bitmap[i]);
> > +		vb->page_bitmap[i] = NULL;
> > +		vb->nr_page_bmap--;
> > +	}
> > +}
> > +
> > +static void kfree_page_bitmap(struct virtio_balloon *vb) {
> > +	int i;
> > +
> > +	for (i = 0; i < vb->nr_page_bmap; i++)
> > +		kfree(vb->page_bitmap[i]);
> > +}
> 
> It might be worth commenting that pair of functions to make it clear why
> they are so different; I guess the kfree_page_bitmap is used just before you
> free the structure above it so you don't need to keep the count/pointers
> updated?
> 

Yes. I will add some comments for that. Thanks!

Liang
 
> Dave
> --
> Dr. David Alan Gilbert / dgilbert@...hat.com / Manchester, UK