linux-kernel - Re: [PATCH RESEND][pciutils] libpci: pci_id_lookup

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]

Date:	Sun, 15 Dec 2013 10:18:39 +0100
From:	Martin Mares <mj@....cz>
To:	Kay Sievers <kay@...y.org>
Cc:	Tom Gundersen <teg@...m.no>, LKML <linux-kernel@...r.kernel.org>,
	linux-pci@...r.kernel.org
Subject: Re: [PATCH RESEND][pciutils] libpci: pci_id_lookup - add udev/hwdb
 support

Hello Kay,

> Libpci and its linear search through megabytes of text files for evey
> new query is too inefficient, that we cannot afford to use it during
> early bootup. It was the largest hit left in bootup profiling on
> machines booting userspace in the sub-1-second range on common
> machines. It was probably never meant to provide efficient queries,
> but it's the reason we can never use it during early boot.

I do not know what you are speaking about -- libpci definitely does
not perform linear scans on pci.ids. It builds a hash table from pci.ids
on the first query and and all subsequent queries are O(1) on average.

				Martin
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/