[Kernel-packages] [Bug 1840934] Re: Change kernel compression method to improve boot speed
** Also affects: ubuntu-z-systems Importance: Undecided Status: New ** Changed in: ubuntu-z-systems Status: New => Fix Released -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1840934 Title: Change kernel compression method to improve boot speed Status in Ubuntu on IBM z Systems: Fix Released Status in linux package in Ubuntu: Fix Released Bug description: Colin King has done some analysis of kernel boot speed using different kernel compression methods. Results for x86 are at: https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/kernel-compression-method.txt https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/boot-speed-compression-5.3-rc4.ods Testing of s390 gave the following: GZIP31528972 LZ4 192348049 LZO 85990145 From Colin: "I used the monotonic TOD timer using the stckf opcode to fetch a 64 bit time value. Not sure how this maps to 'real time' in seconds." Conclusion: We should switch x86 to LZ4 and s390 to LZO. PPC and ARM do not support LZO or LZ4, so we will stick with gzip there. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1840934/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
[Kernel-packages] [Bug 1840934] Re: Change kernel compression method to improve boot speed
>From "Comment bridged from LTC Bugzilla" in a bug discussion:
"FWIW, I verified this on z14, and there clearly lz4 is (as expected)
the fastest decompression algorithm.
With vanilla 5.3-rc6 and defconfig I get the following kernel uncompression
times:
lzo: 27us
lz4: 24us
An initrd (uncompressed size ~55MB) gets these uncompression times:
lzo: 62us
lz4: 49us
So I'd clearly vote to switch to lz4 on s390 as well."
Also:
"I also instrumented the kernel code to only measure the time to decompress the
kernel. If its stckf or stcke doesn't matter in this case.
Note that if you shift a tod clock value 12 bits to the right will give you
microseconds. (All numbers I posted were actually milliseconds not microseconds
by the way).
I measured both runs (z13 + z14) when running within z/VM and IPL'ed
from the punch card reader.
Times used for decompressing the initrd were just extracted from dmesg;
no kernel instrumentation required here, since there are two messages
provided before and after initrd decompression.
Find below an extract of the patch to measure decompression time.
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 7b0d054..cee3d97 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -146,7 +146,10 @@ void startup_kernel(void)
}
if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) {
+ start = get_tod_clock();
img = decompress_kernel();
+ end = get_tod_clock();
+ time = (end - start) >> 12;
memmove((void *)vmlinux.default_lma, img, vmlinux.image_size);
} else if (__kaslr_offset)
memcpy((void *)vmlinux.default_lma, img, vmlinux.image_size);
..."
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https://bugs.launchpad.net/bugs/1840934
Title:
Change kernel compression method to improve boot speed
Status in linux package in Ubuntu:
Fix Released
Bug description:
Colin King has done some analysis of kernel boot speed using different
kernel compression methods. Results for x86 are at:
https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/kernel-compression-method.txt
https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/boot-speed-compression-5.3-rc4.ods
Testing of s390 gave the following:
GZIP31528972
LZ4 192348049
LZO 85990145
From Colin: "I used the monotonic TOD timer using the stckf opcode to
fetch a 64 bit time value. Not sure how this maps to 'real time' in
seconds."
Conclusion: We should switch x86 to LZ4 and s390 to LZO. PPC and ARM
do not support LZO or LZ4, so we will stick with gzip there.
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[Kernel-packages] [Bug 1840934] Re: Change kernel compression method to improve boot speed
Also enable LZ4 for s390x as IBM has provided us with some positive feedback about using this. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1840934 Title: Change kernel compression method to improve boot speed Status in linux package in Ubuntu: Fix Released Bug description: Colin King has done some analysis of kernel boot speed using different kernel compression methods. Results for x86 are at: https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/kernel-compression-method.txt https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/boot-speed-compression-5.3-rc4.ods Testing of s390 gave the following: GZIP31528972 LZ4 192348049 LZO 85990145 From Colin: "I used the monotonic TOD timer using the stckf opcode to fetch a 64 bit time value. Not sure how this maps to 'real time' in seconds." Conclusion: We should switch x86 to LZ4 and s390 to LZO. PPC and ARM do not support LZO or LZ4, so we will stick with gzip there. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1840934/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
[Kernel-packages] [Bug 1840934] Re: Change kernel compression method to improve boot speed
This bug was fixed in the package linux - 5.2.0-15.16 --- linux (5.2.0-15.16) eoan; urgency=medium * Packaging resync (LP: #1786013) - [Packaging] resync getabis * Change kernel compression method to improve boot speed (LP: #1840934) - [Packaging] add build dependencies for compression algorithms linux (5.2.0-14.15) eoan; urgency=medium * eoan/linux: 5.2.0-14.15 -proposed tracker (LP: #1841159) * Packaging resync (LP: #1786013) - [Packaging] resync getabis * Eoan update: v5.2.9 upstream stable release (LP: #1841110) - Revert "PCI: Add missing link delays required by the PCIe spec" - IIO: Ingenic JZ47xx: Set clock divider on probe - iio: cros_ec_accel_legacy: Fix incorrect channel setting - iio: imu: mpu6050: add missing available scan masks - iio: adc: gyroadc: fix uninitialized return code - iio: adc: max9611: Fix misuse of GENMASK macro - staging: gasket: apex: fix copy-paste typo - staging: wilc1000: flush the workqueue before deinit the host - staging: android: ion: Bail out upon SIGKILL when allocating memory. - Staging: fbtft: Fix probing of gpio descriptor - Staging: fbtft: Fix reset assertion when using gpio descriptor - crypto: ccp - Fix oops by properly managing allocated structures - crypto: ccp - Add support for valid authsize values less than 16 - crypto: ccp - Ignore tag length when decrypting GCM ciphertext - driver core: platform: return -ENXIO for missing GpioInt - usb: usbfs: fix double-free of usb memory upon submiturb error - Revert "USB: rio500: simplify locking" - usb: iowarrior: fix deadlock on disconnect - sound: fix a memory leak bug - mmc: cavium: Set the correct dma max segment size for mmc_host - mmc: cavium: Add the missing dma unmap when the dma has finished. - loop: set PF_MEMALLOC_NOIO for the worker thread - bdev: Fixup error handling in blkdev_get() - Input: usbtouchscreen - initialize PM mutex before using it - Input: elantech - enable SMBus on new (2018+) systems - Input: synaptics - enable RMI mode for HP Spectre X360 - coresight: Fix DEBUG_LOCKS_WARN_ON for uninitialized attribute - perf annotate: Fix s390 gap between kernel end and module start - perf db-export: Fix thread__exec_comm() - perf record: Fix module size on s390 - x86/purgatory: Do not use __builtin_memcpy and __builtin_memset - x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS - genirq/affinity: Create affinity mask for single vector - gfs2: gfs2_walk_metadata fix - usb: host: xhci-rcar: Fix timeout in xhci_suspend() - usb: yurex: Fix use-after-free in yurex_delete - usb: typec: ucsi: ccg: Fix uninitilized symbol error - usb: typec: tcpm: free log buf memory when remove debug file - usb: typec: tcpm: remove tcpm dir if no children - usb: typec: tcpm: Add NULL check before dereferencing config - usb: typec: tcpm: Ignore unsupported/unknown alternate mode requests - can: rcar_canfd: fix possible IRQ storm on high load - can: flexcan: fix stop mode acknowledgment - can: flexcan: fix an use-after-free in flexcan_setup_stop_mode() - can: peak_usb: fix potential double kfree_skb() - powerpc: fix off by one in max_zone_pfn initialization for ZONE_DMA - netfilter: nfnetlink: avoid deadlock due to synchronous request_module - vfio-ccw: Set pa_nr to 0 if memory allocation fails for pa_iova_pfn - vfio-ccw: Don't call cp_free if we are processing a channel program - netfilter: Fix rpfilter dropping vrf packets by mistake - netfilter: conntrack: always store window size un-scaled - netfilter: nft_hash: fix symhash with modulus one - scripts/sphinx-pre-install: fix script for RHEL/CentOS - scripts/sphinx-pre-install: don't use LaTeX with CentOS 7 - scripts/sphinx-pre-install: fix latexmk dependencies - rq-qos: don't reset has_sleepers on spurious wakeups - rq-qos: set ourself TASK_UNINTERRUPTIBLE after we schedule - rq-qos: use a mb for got_token - netfilter: nf_tables: Support auto-loading for inet nat - drm/amd/display: No audio endpoint for Dell MST display - drm/amd/display: Clock does not lower in Updateplanes - drm/amd/display: Wait for backlight programming completion in set backlight level - drm/amd/display: fix DMCU hang when going into Modern Standby - drm/amd/display: use encoder's engine id to find matched free audio device - drm/amd/display: put back front end initialization sequence - drm/amd/display: allocate 4 ddc engines for RV2 - drm/amd/display: Fix dc_create failure handling and 666 color depths - drm/amd/display: Only enable audio if speaker allocation exists - drm/amd/display: Increase size of audios array - iscsi_ibft: make ISCSI_IBFT dependson ACPI instead of ISCSI_IBFT_FIND - nl80211: fix NL80211_HE_MAX_CAPABILITY_LEN - mac80211: fix possible memory
[Kernel-packages] [Bug 1840934] Re: Change kernel compression method to improve boot speed
@Dimitri, Seems that for initramfs lz4 makes a lot of sense, see: https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/boot-speed- initramfs-decompression-eoan.ods The load times for LZ4 is slower than the previous default, however, the decompression time makes up for this unless one is booting off really slow media sub-5400 RPM HDD such as slow flash. So, the LZ4 default looks sane to me, lets see how it works out for Eaon. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1840934 Title: Change kernel compression method to improve boot speed Status in linux package in Ubuntu: Fix Committed Bug description: Colin King has done some analysis of kernel boot speed using different kernel compression methods. Results for x86 are at: https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/kernel-compression-method.txt https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/boot-speed-compression-5.3-rc4.ods Testing of s390 gave the following: GZIP31528972 LZ4 192348049 LZO 85990145 From Colin: "I used the monotonic TOD timer using the stckf opcode to fetch a 64 bit time value. Not sure how this maps to 'real time' in seconds." Conclusion: We should switch x86 to LZ4 and s390 to LZO. PPC and ARM do not support LZO or LZ4, so we will stick with gzip there. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1840934/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
[Kernel-packages] [Bug 1840934] Re: Change kernel compression method to improve boot speed
@Dimitri, so you set the defaults w/o any benchmarking stats? I'll see if I can get some time to check what the sane options are per- arch. Colin -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1840934 Title: Change kernel compression method to improve boot speed Status in linux package in Ubuntu: Fix Committed Bug description: Colin King has done some analysis of kernel boot speed using different kernel compression methods. Results for x86 are at: https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/kernel-compression-method.txt https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/boot-speed-compression-5.3-rc4.ods Testing of s390 gave the following: GZIP31528972 LZ4 192348049 LZO 85990145 From Colin: "I used the monotonic TOD timer using the stckf opcode to fetch a 64 bit time value. Not sure how this maps to 'real time' in seconds." Conclusion: We should switch x86 to LZ4 and s390 to LZO. PPC and ARM do not support LZO or LZ4, so we will stick with gzip there. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1840934/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
[Kernel-packages] [Bug 1840934] Re: Change kernel compression method to improve boot speed
I don't think Colin collected any data on initramfs compression, but I subscribed Colin to the bug so he can comment. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1840934 Title: Change kernel compression method to improve boot speed Status in linux package in Ubuntu: Fix Committed Bug description: Colin King has done some analysis of kernel boot speed using different kernel compression methods. Results for x86 are at: https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/kernel-compression-method.txt https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/boot-speed-compression-5.3-rc4.ods Testing of s390 gave the following: GZIP31528972 LZ4 192348049 LZO 85990145 From Colin: "I used the monotonic TOD timer using the stckf opcode to fetch a 64 bit time value. Not sure how this maps to 'real time' in seconds." Conclusion: We should switch x86 to LZ4 and s390 to LZO. PPC and ARM do not support LZO or LZ4, so we will stick with gzip there. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1840934/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
[Kernel-packages] [Bug 1840934] Re: Change kernel compression method to improve boot speed
Should we match these defaults for initramfs too? At the moment I have switched to lz4 across the board, but maybe it does make sense to use lzo on s390x and gzip on armhf, etc. Should I escalate to IBM supporting lz4 on ppc64le? -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1840934 Title: Change kernel compression method to improve boot speed Status in linux package in Ubuntu: Fix Committed Bug description: Colin King has done some analysis of kernel boot speed using different kernel compression methods. Results for x86 are at: https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/kernel-compression-method.txt https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/boot-speed-compression-5.3-rc4.ods Testing of s390 gave the following: GZIP31528972 LZ4 192348049 LZO 85990145 From Colin: "I used the monotonic TOD timer using the stckf opcode to fetch a 64 bit time value. Not sure how this maps to 'real time' in seconds." Conclusion: We should switch x86 to LZ4 and s390 to LZO. PPC and ARM do not support LZO or LZ4, so we will stick with gzip there. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1840934/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
[Kernel-packages] [Bug 1840934] Re: Change kernel compression method to improve boot speed
** Changed in: linux (Ubuntu) Importance: Undecided => Medium ** Changed in: linux (Ubuntu) Status: Incomplete => Fix Committed ** Changed in: linux (Ubuntu) Assignee: (unassigned) => Seth Forshee (sforshee) -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1840934 Title: Change kernel compression method to improve boot speed Status in linux package in Ubuntu: Fix Committed Bug description: Colin King has done some analysis of kernel boot speed using different kernel compression methods. Results for x86 are at: https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/kernel-compression-method.txt https://kernel.ubuntu.com/~cking/boot-speed-eoan-5.3/boot-speed-compression-5.3-rc4.ods Testing of s390 gave the following: GZIP31528972 LZ4 192348049 LZO 85990145 From Colin: "I used the monotonic TOD timer using the stckf opcode to fetch a 64 bit time value. Not sure how this maps to 'real time' in seconds." Conclusion: We should switch x86 to LZ4 and s390 to LZO. PPC and ARM do not support LZO or LZ4, so we will stick with gzip there. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1840934/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
