| Message ID | 20190614181619.64905-1-gaoxiang25@huawei.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | staging: erofs: decompression inplace approach | expand |
On Sat, Jun 15, 2019 at 02:16:11AM +0800, Gao Xiang wrote: > At last, this is RFC patch v1, which means it is not suitable for > merging soon... I'm still working on it, testing its stability > these days and hope these patches get merged for 5.3 LTS > (if 5.3 is a LTS version). Why would 5.3 be a LTS kernel? curious as to how you came up with that :) thanks, greg k-h
On 2019/6/18 4:36, Greg Kroah-Hartman wrote: > On Sat, Jun 15, 2019 at 02:16:11AM +0800, Gao Xiang wrote: >> At last, this is RFC patch v1, which means it is not suitable for >> merging soon... I'm still working on it, testing its stability >> these days and hope these patches get merged for 5.3 LTS >> (if 5.3 is a LTS version). > > Why would 5.3 be a LTS kernel? > > curious as to how you came up with that :) My personal thought is about one LTS kernel one year... Usually 5 versions after the previous kernel...(4.4 -> 4.9 -> 4.14 -> 4.19), which is not suitable for all historical LTSs...just prepare for 5.3... Thanks, Gao Xiang > > thanks, > > greg k-h >
On Tue, Jun 18, 2019 at 09:47:08AM +0800, Gao Xiang wrote: > > > On 2019/6/18 4:36, Greg Kroah-Hartman wrote: > > On Sat, Jun 15, 2019 at 02:16:11AM +0800, Gao Xiang wrote: > >> At last, this is RFC patch v1, which means it is not suitable for > >> merging soon... I'm still working on it, testing its stability > >> these days and hope these patches get merged for 5.3 LTS > >> (if 5.3 is a LTS version). > > > > Why would 5.3 be a LTS kernel? > > > > curious as to how you came up with that :) > > My personal thought is about one LTS kernel one year... > Usually 5 versions after the previous kernel...(4.4 -> 4.9 -> 4.14 -> 4.19), > which is not suitable for all historical LTSs...just prepare for 5.3... I try to pick the "last" kernel that is released each year, which sometimes is 5 kernels, sometimes 4, sometimes 6, depending on the release cycle. So odds are it will be 5.4 for the next LTS kernel, but we will not know more until it gets closer to release time. thanks, greg k-h
On 2019/6/18 13:47, Greg Kroah-Hartman wrote: > On Tue, Jun 18, 2019 at 09:47:08AM +0800, Gao Xiang wrote: >> >> >> On 2019/6/18 4:36, Greg Kroah-Hartman wrote: >>> On Sat, Jun 15, 2019 at 02:16:11AM +0800, Gao Xiang wrote: >>>> At last, this is RFC patch v1, which means it is not suitable for >>>> merging soon... I'm still working on it, testing its stability >>>> these days and hope these patches get merged for 5.3 LTS >>>> (if 5.3 is a LTS version). >>> >>> Why would 5.3 be a LTS kernel? >>> >>> curious as to how you came up with that :) >> >> My personal thought is about one LTS kernel one year... >> Usually 5 versions after the previous kernel...(4.4 -> 4.9 -> 4.14 -> 4.19), >> which is not suitable for all historical LTSs...just prepare for 5.3... > > I try to pick the "last" kernel that is released each year, which > sometimes is 5 kernels, sometimes 4, sometimes 6, depending on the > release cycle. > > So odds are it will be 5.4 for the next LTS kernel, but we will not know > more until it gets closer to release time. Thanks for kindly explanation :) Anyway, I will test these patches, land to our commerical products and try the best efforts on making it more stable for Linux upstream to merge. Thanks, Gao Xiang > > thanks, > > greg k-h >
On Tue, Jun 18, 2019 at 02:18:00PM +0800, Gao Xiang wrote: > > > On 2019/6/18 13:47, Greg Kroah-Hartman wrote: > > On Tue, Jun 18, 2019 at 09:47:08AM +0800, Gao Xiang wrote: > >> > >> > >> On 2019/6/18 4:36, Greg Kroah-Hartman wrote: > >>> On Sat, Jun 15, 2019 at 02:16:11AM +0800, Gao Xiang wrote: > >>>> At last, this is RFC patch v1, which means it is not suitable for > >>>> merging soon... I'm still working on it, testing its stability > >>>> these days and hope these patches get merged for 5.3 LTS > >>>> (if 5.3 is a LTS version). > >>> > >>> Why would 5.3 be a LTS kernel? > >>> > >>> curious as to how you came up with that :) > >> > >> My personal thought is about one LTS kernel one year... > >> Usually 5 versions after the previous kernel...(4.4 -> 4.9 -> 4.14 -> 4.19), > >> which is not suitable for all historical LTSs...just prepare for 5.3... > > > > I try to pick the "last" kernel that is released each year, which > > sometimes is 5 kernels, sometimes 4, sometimes 6, depending on the > > release cycle. > > > > So odds are it will be 5.4 for the next LTS kernel, but we will not know > > more until it gets closer to release time. > > Thanks for kindly explanation :) > > Anyway, I will test these patches, land to our commerical products and try the best > efforts on making it more stable for Linux upstream to merge. Sounds great. But why do you need to add compression to get this code out of staging? Why not move it out now and then add compression and other new features to it then? thanks, greg k-h
On 2019/6/18 14:45, Greg Kroah-Hartman wrote: > On Tue, Jun 18, 2019 at 02:18:00PM +0800, Gao Xiang wrote: >> >> >> On 2019/6/18 13:47, Greg Kroah-Hartman wrote: >>> On Tue, Jun 18, 2019 at 09:47:08AM +0800, Gao Xiang wrote: >>>> >>>> >>>> On 2019/6/18 4:36, Greg Kroah-Hartman wrote: >>>>> On Sat, Jun 15, 2019 at 02:16:11AM +0800, Gao Xiang wrote: >>>>>> At last, this is RFC patch v1, which means it is not suitable for >>>>>> merging soon... I'm still working on it, testing its stability >>>>>> these days and hope these patches get merged for 5.3 LTS >>>>>> (if 5.3 is a LTS version). >>>>> >>>>> Why would 5.3 be a LTS kernel? >>>>> >>>>> curious as to how you came up with that :) >>>> >>>> My personal thought is about one LTS kernel one year... >>>> Usually 5 versions after the previous kernel...(4.4 -> 4.9 -> 4.14 -> 4.19), >>>> which is not suitable for all historical LTSs...just prepare for 5.3... >>> >>> I try to pick the "last" kernel that is released each year, which >>> sometimes is 5 kernels, sometimes 4, sometimes 6, depending on the >>> release cycle. >>> >>> So odds are it will be 5.4 for the next LTS kernel, but we will not know >>> more until it gets closer to release time. >> >> Thanks for kindly explanation :) >> >> Anyway, I will test these patches, land to our commerical products and try the best >> efforts on making it more stable for Linux upstream to merge. > > Sounds great. > > But why do you need to add compression to get this code out of staging? > Why not move it out now and then add compression and other new features > to it then? Move out of staging could be over several linux versions since I'd like to get majority fs people agreed to this. Decompression inplace is an important part of erofs to show its performance benefits over existed compress filesystems and I tend to merge it in advance. Thanks, Gao Xiang > > thanks, > > greg k-h >
On Tue, Jun 18, 2019 at 02:52:21PM +0800, Gao Xiang wrote: > > > On 2019/6/18 14:45, Greg Kroah-Hartman wrote: > > On Tue, Jun 18, 2019 at 02:18:00PM +0800, Gao Xiang wrote: > >> > >> > >> On 2019/6/18 13:47, Greg Kroah-Hartman wrote: > >>> On Tue, Jun 18, 2019 at 09:47:08AM +0800, Gao Xiang wrote: > >>>> > >>>> > >>>> On 2019/6/18 4:36, Greg Kroah-Hartman wrote: > >>>>> On Sat, Jun 15, 2019 at 02:16:11AM +0800, Gao Xiang wrote: > >>>>>> At last, this is RFC patch v1, which means it is not suitable for > >>>>>> merging soon... I'm still working on it, testing its stability > >>>>>> these days and hope these patches get merged for 5.3 LTS > >>>>>> (if 5.3 is a LTS version). > >>>>> > >>>>> Why would 5.3 be a LTS kernel? > >>>>> > >>>>> curious as to how you came up with that :) > >>>> > >>>> My personal thought is about one LTS kernel one year... > >>>> Usually 5 versions after the previous kernel...(4.4 -> 4.9 -> 4.14 -> 4.19), > >>>> which is not suitable for all historical LTSs...just prepare for 5.3... > >>> > >>> I try to pick the "last" kernel that is released each year, which > >>> sometimes is 5 kernels, sometimes 4, sometimes 6, depending on the > >>> release cycle. > >>> > >>> So odds are it will be 5.4 for the next LTS kernel, but we will not know > >>> more until it gets closer to release time. > >> > >> Thanks for kindly explanation :) > >> > >> Anyway, I will test these patches, land to our commerical products and try the best > >> efforts on making it more stable for Linux upstream to merge. > > > > Sounds great. > > > > But why do you need to add compression to get this code out of staging? > > Why not move it out now and then add compression and other new features > > to it then? > > Move out of staging could be over several linux versions since I'd like to get > majority fs people agreed to this. You never know until you try :) > Decompression inplace is an important part of erofs to show its performance > benefits over existed compress filesystems and I tend to merge it in advance. There is no requirement to show benefits over other filesystems in order to get it merged, but I understand the feeling. That's fine, we can wait, we are not going anywhere... thanks, greg k-h
On 2019/6/18 15:05, Greg Kroah-Hartman wrote: > On Tue, Jun 18, 2019 at 02:52:21PM +0800, Gao Xiang wrote: >> >> >> On 2019/6/18 14:45, Greg Kroah-Hartman wrote: >>> On Tue, Jun 18, 2019 at 02:18:00PM +0800, Gao Xiang wrote: >>>> >>>> >>>> On 2019/6/18 13:47, Greg Kroah-Hartman wrote: >>>>> On Tue, Jun 18, 2019 at 09:47:08AM +0800, Gao Xiang wrote: >>>>>> >>>>>> >>>>>> On 2019/6/18 4:36, Greg Kroah-Hartman wrote: >>>>>>> On Sat, Jun 15, 2019 at 02:16:11AM +0800, Gao Xiang wrote: >>>>>>>> At last, this is RFC patch v1, which means it is not suitable for >>>>>>>> merging soon... I'm still working on it, testing its stability >>>>>>>> these days and hope these patches get merged for 5.3 LTS >>>>>>>> (if 5.3 is a LTS version). >>>>>>> >>>>>>> Why would 5.3 be a LTS kernel? >>>>>>> >>>>>>> curious as to how you came up with that :) >>>>>> >>>>>> My personal thought is about one LTS kernel one year... >>>>>> Usually 5 versions after the previous kernel...(4.4 -> 4.9 -> 4.14 -> 4.19), >>>>>> which is not suitable for all historical LTSs...just prepare for 5.3... >>>>> >>>>> I try to pick the "last" kernel that is released each year, which >>>>> sometimes is 5 kernels, sometimes 4, sometimes 6, depending on the >>>>> release cycle. >>>>> >>>>> So odds are it will be 5.4 for the next LTS kernel, but we will not know >>>>> more until it gets closer to release time. >>>> >>>> Thanks for kindly explanation :) >>>> >>>> Anyway, I will test these patches, land to our commerical products and try the best >>>> efforts on making it more stable for Linux upstream to merge. >>> >>> Sounds great. >>> >>> But why do you need to add compression to get this code out of staging? >>> Why not move it out now and then add compression and other new features >>> to it then? >> >> Move out of staging could be over several linux versions since I'd like to get >> majority fs people agreed to this. > > You never know until you try :) Thanks for your encouragement :) Actually, I personally gave a brief talk on this year LSF/MM 2019 but since I cannot speak English well so the entire effect is not good enough :(... I will personally contact with important people ... to get their agreements on this file system soon. > >> Decompression inplace is an important part of erofs to show its performance >> benefits over existed compress filesystems and I tend to merge it in advance. > > There is no requirement to show benefits over other filesystems in order > to get it merged, but I understand the feeling. That's fine, we can > wait, we are not going anywhere... Thanks again. I am just proving that the erofs solution may be one of the best compression solutions in performance first scenerio :) Thanks, Gao Xiang > > thanks, > > greg k-h >
Hi, After working on for more than half a year, the detail of erofs decompression inplace is almost determined and ready for linux-next. Currently, inplace IO is used if the whole compressed data is used in order to reduce compressed pages extra memory overhead and an extra memcpy (the only one memcpy) will be used for each inplace IO since temporary buffer is needed to keep decompressing safe for inplace IO. However, most of lz-based decompression algorithms support decompression inplace by their algorithm designs, such as LZ4, LZO, etc. If iend - oend margin is large enough, decompression inplace can be done in the same buffer safely, as illustrated below: start of compressed logical extent | end of this logical extent | | ______v___________________________v________ ... | page 6 | page 7 | page 8 | page 9 | ... |__________|__________|__________|__________| . ^ . ^ . |compressed| . | data | . . . |< dstsize >|<margin>| oend iend op ip Fixed-size output compression can make the full use of this feature to reduce memory overhead and avoid extra memcpy compared with fixed-size input compression since iend is strictly not less than oend for fixed-size output compression with inplace IO to last pages. In addition, erofs compression indexes have been improved as well by introducing compacted compression indexes. These two techniques all benefit sequential read (on x86_64, 710.8MiB/s -> 755.4MiB/s; on Kirin980, 725MiB/s -> 812MiB/s) therefore erofs could have similar sequential read performance against ext4 in a larger CR range on high-spend SSD / NVMe devices as well. However, note that it is _cpu vs storage device_ balance, there is no absolute performance conclusion for all on-market combinations. At last, this is RFC patch v1, which means it is not suitable for merging soon... I'm still working on it, testing its stability these days and hope these patches get merged for 5.3 LTS (if 5.3 is a LTS version). The series is based on staging-next with the following patches, which can be merged in advance: [PATCH v3 1/2] staging: erofs: add requirements field in superblock [PATCH v2 2/2] staging: erofs: rename data_mapping_mode to datamode Test images: name size CR enwik9 1000000000 1.00 enwik9_4k.squashfs.img 621211648 1.61 enwik9_4k.erofs.img 558133248 1.79 enwik9_8k.squashfs.img 556191744 1.80 enwik9_16k.squashfs.img 502661120 1.99 enwik9_128k.squashfs.img 398204928 2.51 Test Environment: CPU: Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz (4 cores, 8 threads) DDR: 8G SSD: INTEL SSDPEKKF360G7H Kernel: Linux 5.2-rc3+ (with lz4-1.8.3 algorithm) Test configuration: squashfs: CONFIG_SQUASHFS=y CONFIG_SQUASHFS_FILE_DIRECT=y CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU=y CONFIG_SQUASHFS_LZ4=y CONFIG_SQUASHFS_4K_DEVBLK_SIZE=y erofs: CONFIG_EROFS_FS_USE_VM_MAP_RAM=y CONFIG_EROFS_FS_ZIP=y CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT=1 CONFIG_EROFS_FS_ZIP_CACHE_BIPOLAR=y with intel_pstate=disable, 8 cpus on at 1801000 scaling_{min,max}_freq, userspace scaling_governor Sequential read results (MiB/s): 1 2 3 4 5 avg enwik9_4k.ext4.img 767 770 738 726 724 745 enwik9_4k.erofs.img 756 745 770 746 760 755.4 enwik9_4k.squashfs.img 90.3 83.0 94.3 90.7 92.6 90.18 enwik9_8k.squashfs.img 111 108 110 108 110 109.4 enwik9_16k.squashfs.img 158 163 146 165 174 161.2 enwik9_128k.squashfs.img 324 314 262 262 296 291.6 Thanks, Gao Xiang Gao Xiang (8): staging: erofs: add compacted ondisk compression indexes staging: erofs: add compacted compression indexes support staging: erofs: move per-CPU buffers implementation to utils.c staging: erofs: move stagingpage operations to compress.h staging: erofs: introduce generic decompression backend staging: erofs: introduce LZ4 decompression inplace staging: erofs: switch to new decompression backend staging: erofs: integrate decompression inplace drivers/staging/erofs/Makefile | 2 +- drivers/staging/erofs/compress.h | 62 ++++ drivers/staging/erofs/data.c | 4 +- drivers/staging/erofs/decompressor.c | 321 ++++++++++++++++++ drivers/staging/erofs/erofs_fs.h | 60 +++- drivers/staging/erofs/inode.c | 12 +- drivers/staging/erofs/internal.h | 58 +++- drivers/staging/erofs/unzip_vle.c | 368 ++------------------ drivers/staging/erofs/unzip_vle.h | 38 +-- drivers/staging/erofs/unzip_vle_lz4.c | 229 ------------- drivers/staging/erofs/utils.c | 12 + drivers/staging/erofs/zmap.c | 462 ++++++++++++++++++++++++++ 12 files changed, 996 insertions(+), 632 deletions(-) create mode 100644 drivers/staging/erofs/compress.h create mode 100644 drivers/staging/erofs/decompressor.c delete mode 100644 drivers/staging/erofs/unzip_vle_lz4.c create mode 100644 drivers/staging/erofs/zmap.c