Blogs: Kernel Miscellaneous Stuff

[menotu]

Posted by Michael Larabel on February 20, 2013

Linux 3.9 Supports Lightweight Suspend, New PM Features

The feature pull for ACPI and power management updates to be introduced in the Linux 3.9 kernel were merged.

This merge does incorporate the recently talked about fixes/improvements and other power-related updates. Notable to this merge is the new Intel P-State Linux driver.

To this 3.9 feature merge is also ACPI power resource handling and device PM updates, support for the Intel Lynxpoint LPSS, a cpuidle driver update including Intel Haswell support, a cpufreq driver for Marvell Kirkwood SoCs, cpufreq support for Calxeda Highbank ARM processors, a cpufreq driver for the Freescale i.MX6Q SoC, and support for lightweight suspend. There's also fixes and minor improvements scattered throughout for cpuidle, ACPI, and ACPICA.

In regards to the lightweight suspend support, the new Linux kernel feature is talked about within Intel Driver Works On "PM Suspend Freeze" Support.

http://www.phoronix.com/scan.php?page=news_item&px=MTMwNzU

[menotu]

Written by Michael Larabel - Published on February 21, 2013

F2FS File-System Runs Great On SDHC Storage

Earlier this week I performed some F2FS file-system benchmarks on the Linux 3.8 kernel with an Intel X25 Solid-State Drive (SSD) compared to the EXT4, Btrfs, and other file-systems. Out today are benchmarks of the Flash-Friendly File-System from an SDHC card on Linux.

This benchmarking of F2FS on an SDHC card isn't as nearly exhaustive as the SSD benchmarking of F2FS earlier in the week that also draw in EXT4, Btrfs, JFS, XFS, and ReiserFS. Due to the slower speeds of the SDHC card, only EXT4 and Btrfs were used as comparison against F2FS. Tux3 also isn't being tested in this article due to it not yet being mainline.

The SDHC card being used for this benchmarking was a Patriot LX Series 16GB Class 10 SDHC card. Benchmarking occurred from an Intel Core i5 "Sandy Bridge" laptop running another distro 13.04 with the vanilla Linux 3.8 final kernel.

Coming in a separate article will also be benchmarks of the F2FS Linux file-system when tested on USB flash storage. Overall the results in this article show F2FS as being capable of outperforming EXT4 and Btrfs from the SDHC storage.

Full testing details

More info on F2FS Flash-Friendly File-System

http://www.pclinuxos.com/forum/index.php/topic,113480.0.html

[µT6]

good, now, i only have to wait 5 years to have that stable kernel and have a bunch of money to use all that speed improvements 

[menotu]

Posted by Michael Larabel on February 23, 2013

Linux 3.9 Brings Zero-Power Optical Device Driver

With the ATA pull for the Linux 3.9 kernel finally comes ZPODD, the Zero-Power Optical Device Driver.

I first wrote about ZPODD support on Linux last May in Better Power Savings With ZPODD On Linux. The Zero-Power Optical Disk Drive is a feature of the Serail ATA 3.1 specification that allows for idle SATA optical disk drives to zero out their energy use if it's not being utilized, thus better energy efficiency on Linux.

It's taken a while, but with the Linux 3.9 kernel the Zero-Power Optical Device Driver is finally being mainlined. The libata pull for Linux 3.9 also adds in a Serial ATA driver for the R-Car SoC and some other random changes. The pull request can be found on the Linux kernel mailing list.

http://www.phoronix.com/scan.php?page=news_item&px=MTMxMDA

[menotu]

Samsung Brings Fixes To F2FS In Linux 3.9 Kernel

http://www.pclinuxos.com/forum/index.php/topic,113480.msg969732.html#msg969732

[menotu]

Posted by Michael Larabel on February 28, 2013

Top Features For The Linux 3.9 Kernel

The merge window for the Linux 3.9 kernel is coming to a close and most of the major merges have already occurred, so let's take a look at some of the best new features coming to this next Linux kernel release.

A Linux 3.9 kernel feature overview article will come later on at Phoronix to more exhaustively cover all of the features, but some of the most interesting merges from my perspective include:

- Continued work on F2FS by Samsung developers. The "Flash Friendly File-System" was just introduced in Linux 3.8, but initial testing has revealed it runs really great and also does well for SDHC storage. This may be one of the reasons (along with AArch64) why Google is quick to play with Linux 3.8 for Android.

- Power-saving improvements including the Zero-Power Optical Device Driver and more ACPI / ASPM work. There's also a new lightweight suspend mode.

- Improved ARM support, which I enjoy a lot because ARM performance is becoming very interesting.

- Major Linux audio/sound improvements.

- Google and other developers have been working to mainline all of Google's Goldfish, code for the Android emulator.

- DRM graphics driver changes, including early AMD Radeon HD 8000 series support, but aside from that and lots of internal changes to the various open-source graphics drivers, there isn't anything too outstanding as it concerns end-users

- Hardware support improvements. There's the usual roundabout of new device drivers, expanded product support for existing drivers, etc. Among the 3.9 work includes new input drivers, Synopsys ARC700 CPU support, and IBM continues investing greatly in the Linux support for their next-generation POWER8 CPUs.

http://www.phoronix.com/scan.php?page=news_item&px=MTMxNTA

[menotu]

Posted by Michael Larabel on March 29, 2013

ZFS On Linux Is Now Set For "Wide Scale Deployment"

The Sun/Oracle ZFS file-system port to the Linux kernel has now been deemed ready with its new release as "ready for wide scale deployment on everything from desktops to super computers." Will you use ZFS On Linux?

The ZFS On Linux project is the native port of the file-system as a Linux kernel module along with related Solaris bits to make the port work in the Linux world. This isn't the ZFS FUSE implementation running in user-space. However, due to ZFS still being under the CDDL that's incompatible with the GPL and no re-licensing by Oracle, there still stands very little chance of seeing the ZFS file-system enter the mainline Linux kernel code-base anytime soon.

The ZFS On Linux work is lead by the Lawrence Livermore National Laboratory and other developers. The developers feel "ZoL" is now ready for wide-scale deployment after it's been in use by "real users" for the past two years. They noted this when announcing the ZFS On Linux 0.6.1 release this week.


ZFS On Linux 0.6.1 changes include Linux 3.9 kernel compatibility, a new snapdev property, improved slab object reclaim behavior, a disk cache flushing fix, hot spare functionality fix, updated DKMS and KMOD packaging, new man pages, and much more.

More details on ZFS On Linux 0.6.1 can be found via the Google Groups announcement.

New benchmarks of ZFS On Linux compared to other Linux file-systems will likely come soon. The last time at Phoronix we did extensive ZFS Linux benchmarks was last summer with ZFS On Linux With Ubuntu 12.04 LTS.

http://www.phoronix.com/scan.php?page=news_item&px=MTMzODM

[menotu]

Intel Mesa Driver Gets KDE KWin Optimizations

http://www.pclinuxos.com/forum/index.php/topic,105011.msg978767.html#msg978767

[µT6]

good, i need that

[menotu]

Posted by Michael Larabel on April 03, 2013

Another EXT4 Corruption Bug Gets Fixed (created on 3.9 kernel merge window)

A few months back there was an EXT4 file-system corruption bug that impacted stable Linux kernel releases and was widely-covered. Today, another EXT4 file-system bug was corrected within the mainline Linux kernel.

Fortunately, compared to the corruption bug a few months back that affected stable kernel releases, this new corruption issue isn't nearly as bad. This new issue was only created a few weeks prior with the Linux 3.9 kernel merge window and thus hasn't reached a stable kernel release. Additionally, the issue only affects big endian systems, like some from PowerPC, MIPS, and SPARC.

The commit to "fix big-endian bugs which could cause fs corruptions" was merged on Wednesday with this commit. For those users of EXT4 on big endian systems wishing to learn more about the potential EXT4 corruption issue from Linux 3.9 development kernels, see the EXT4 mailing list.

phoronix + links

[menotu]

Posted by Michael Larabel on April 14, 2013

Linux 3.9-rc7 Might Fix A Rare 32-bit PAE Bug

Linus Torvalds has announced the release of the Linux 3.9-rc7 kernel with the final release of the Linux 3.9 kernel likely being imminent.

Torvalds announced the 3.9-rc7 kernel release on Sunday evening. The most prominent change that he mentions is a rare issue affecting only 32-bit PAE systems that came down to a "rather subtle TLB invalidate bug." As it affects end-users, this bug might be why some Google Chrome users have experienced bad page-table bugs. Linus believes the problem is quite rare.

Aside from the PAE bug-fix, there's a variety of other small fixes throughout the open-source kernel as well.

Torvalds didn't provide any new update on when he plans to release Linux 3.9, but last week he mentioned it should be here in about two weeks -- or about one week from now.

http://www.phoronix.com/scan.php?page=news_item&px=MTM1MTg

[menotu]

F2FS major enhancement patches (3.10 kernel)

http://www.pclinuxos.com/forum/index.php/topic,113480.msg988496.html#msg988496

[menotu]

Posted by Michael Larabel on June 04, 2013

F2FS Patches Provide Support For Inline Data

For potential merging in an upcoming Linux kernel release are new patches that allow storing small files as inline data for F2FS.

The Flash-Friendly File-System patches published on Monday allow storing small files directly in the file-system's inode rather than storing it elsewhere and connecting it via a single block address. The F2FS inode is quite large and can then allow storing files about 3.6K and smaller directly inline.

With the Linux 3.8 kernel, EXT4 gained inline data support. The new F2FS patches are currently under a "request for comments" state and can be found on the Linux kernel mailing list.

http://www.phoronix.com/scan.php?page=news_item&px=MTM4MzQ

[menotu]

Posted by Michael Larabel on June 05, 2013

TPPS: A New Linux Kernel I/O Scheduler

The Tiny Parallel Proportion Scheduler (TPPS) is a new I/O scheduler for Linux to appear on the kernel mailing list.

Robin Dong explains in his mailing list announcement for this new I/O scheduler to use cgroup on high-speed devices., "We want to use blkio.cgroup on high-speed device (like fusionio) for our mysql clusters. After testing different io-scheduler, we found that cfq is too slow and deadline can't run on cgroup. So we developed a new io-scheduler: tpps (Tiny Parallel Proportion Scheduler).It dispatch requests only by using their individual weight and total weight (proportion) therefore it's simply and efficient."

The kernel configuration description describes this new I/O scheduler as, "The TPPS I/O scheduler tries to distribute iops proportional among all cgroups in the system. It should also provide a low latency working environment, suitable for flash-based device."

Should this Tiny Parallel Proportion Scheduler I/O scheduler gain steam and be on track for merging into a future Linux kernel release, you can bet it will be benchmarked on Phoronix.

http://www.phoronix.com/scan.php?page=news_item&px=MTM4NDM

[gseaman]

good, now, i only have to wait 5 years to have that stable kernel and have a bunch of money to use all that speed improvements 

I can't help you with the money for new hardware , but I can safely assure you that you won't have to wait five years for a 3.9.x kernel. I am running it now and will submit it for testing in a couple of days.

Galen