![]() Seconds, but with readahead, it meets the target of five. With readahead turned off, the system boots in seven SReadahead uses the "idle" I/O scheduler, so that if Pieces of the file we actually use ", Arjan said. To boot, set by the maximum transfer speed of theįlash storage: 3 seconds of I/O at 25MB/s. There's a hard limit of 75MB of reads in order Some suggestions for reordering blocks on disk to Soon as Arjan can go over it with ext3 filesystem SReadahead is to be released next week on ,Īnd the kernel patch is intended for mainline as Wait to read from disk, since everything it needs 4).Īt maximum for most of the boot time, thanks When HAL does its CPU-intensive startup (fig. Half a second probing for video modes, and that's The arrangement of tasks helps get efficient use ![]() Old-school /dev directory so that boot doesn't depend Udev is used only to support devices that mightīe added later-the system has a persistent, Manager for hot-plugged devices, then networking. Third set of programs to start is the Hardware The critical path: filesystem check, then the D-Bus "sReadahead" process, to read blocks fromĭisk so that they're cached in memory, second, To do three things at the same time: first, an The order of tasks that init handles is modified Traditionally is the first userspace program to run.īut the Intel team went back to the original init. How they did it: readahead and initĪs a replacement for the historic "init" that That enables readahead, which is part of the earlyīoot process. It has to read at boot, then makes that informationĪvailable to userspace when booting is complete. The kernel now keeps track of which blocks One more kernel change was a small patch to support Half a second by 2.6.28, thanks to a brand-new fix Half a second but we got it down to a second and we Host Controller Interface (UHCI), in order to handle To handle storage, at the same time as the Universal Host Controller Interface (AHCI) initialization, He suggested buildingĪn initrd-based image to cover the remaining 5%.Īsynchronous initialization of some subsystems.įor example, the modified kernel starts the Advanced " With a handful of modules you cover 95% of Modules required for boot must be built into the The kernel has to be built without initrd, which "Early boot" including init scripts and background Gets one second to start, including all modules. Much more than the Intel team spent on booting fastĮnough not to need one. Time that distributions spend on splash screens is Arjan andĪuke agreed, " We hate splash screens. Pure CPU time, to display the background image.īoth distributions use splash screens. And Ubuntu's GDM takes another 2.5 seconds of " Everybody else pays for the binary driver ", Arjan License-restricted drivers takes 2.5 seconds-onĪ system with no restricted drivers needed. Modprobe running a shell running modprobe, whichĮnds up loading a single module. Ubuntu's boot time is about the same: two Startup, in order to build its keyboard mappings. System runs the C preprocessor and compiler on It took five seconds.įedora was not to blame for everything. Tool for finding problems with Security Enhanced On Fedora was "setroubleshootd," a useful Two seconds to start "sendmail." " Everybody paysīecause someone else wants to run a mail server ",Īrjan said, and suggested that for the commonįor outgoing mail-the user can simply run ssmtp. It spends a full second starting the loopbackĭevice-checking to see if all the network System does some apparently time-wasting things. In aīootchart graph of the Fedora boot (fig. Said he has run the same load on a ThinkPad and achievedīy Ziga Mahkovec, offers some details. Hard disk will have to take longer to start up: Arjan Not include bringing up the network, but did include Microsoft does this.) The "done booting" time did Up the desktop while still starting services behind Whole system, and make each step of the boot finish ![]() Instead of savingĪ second here and there, set a time budget for the How did they do it? Arjan said it starts with Than the time needed for the projector to sync. Since the time required to finish booting was less They had to hold up the EEE PC for the audience, Mark with two software loads: one modified Fedora and one The hardware wasĪn Asus EEE PC, which has solid-state storage,Īnd the two developers beat the five second Source Technology Center, demonstrated a Linux PowerTOP, and Auke Kok, another Linux developer at Ven, Linux developer at Intel and author of This article was contributed by Don MartiĪt the Linux Plumbers Conference Thursday,
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