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2019-09-05dm writecache: skip writecache_wait for pmem modeHuaisheng Ye1-1/+2
The array bio_in_progress[2] only have chance to be increased and decreased with ssd mode. For pmem mode, they are not involved at all. So skip writecache_wait_for_ios in writecache_flush for pmem. Suggested-by: Doris Yu <tyu1@lenovo.com> Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26dm writecache: optimize performance by sorting the blocks for writeback_allHuaisheng Ye1-3/+16
During the process of writeback, the blocks, which have been placed in wbl.list for writeback soon, are partially ordered for the contiguous ones. When writeback_all has been set, for most cases, also by default, there will be a lot of blocks in pmem need to writeback at the same time. For this case, we could optimize the performance by sorting all blocks in wbl.list. writecache_writeback doesn't need to get blocks from the tail of wc->lru, whereas from the first rb_node from the rb_tree. The benefit is that, writecache_writeback doesn't need to have any cost to sort the blocks, because of all blocks are incremental originally in rb_tree. There will be a writecache_flush when writeback_all begins to work, that will eliminate duplicate blocks in cache by committed/uncommitted. Testing platform: Thinksystem SR630 with persistent memory. The cache comes from pmem, which has 1006MB size. The origin device is HDD, 2GB of which for using. Testing steps: 1) dmsetup create mycache --table '0 4194304 writecache p /dev/sdb1 /dev/pmem4 4096 0' 2) fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 3) time dmsetup message /dev/mapper/mycache 0 flush Here is the results below, With the patch: # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 iops : min= 1582, max=199470, avg=5305.94, stdev=21273.44, samples=197 # time dmsetup message /dev/mapper/mycache 0 flush real 0m44.020s user 0m0.002s sys 0m0.003s Without the patch: # fio -filename=/dev/mapper/mycache -direct=1 -iodepth=20 -rw=randwrite -ioengine=libaio -bs=4k -loops=1 -size=2g -group_reporting -name=mytest1 iops : min= 1202, max=197650, avg=4968.67, stdev=20480.17, samples=211 # time dmsetup message /dev/mapper/mycache 0 flush real 1m39.221s user 0m0.001s sys 0m0.003s I also have checked the data accuracy with this patch by making EXT4 filesystem on mycache, then mount it for checking md5 of files on that. The test result is positive, with this patch it could save more than half of time when writeback_all. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26dm writecache: add unlikely for getting two block with same LBAHuaisheng Ye1-2/+2
In function writecache_writeback, entries g and f has same original sector only happens at entry f has been committed, but entry g has NOT yet. The probability of this happening is very low in the following 256 blocks at most of entry e. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-26dm writecache: remove unused member pointer in writeback_structHuaisheng Ye1-1/+0
The stucture member pointer page in writeback_struct never has been used actually. Remove it. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-26dm writecache: avoid unnecessary lookups in writecache_find_entry()Mikulas Patocka1-6/+5
This is a small optimization in writecache_find_entry(). If we go past the condition "if (unlikely(!node))", we can be certain that there is no entry in the tree that has the block equal to the "block" variable. Consequently, we can return the next entry directly, we don't need to go to the second part of the function that finds the entry with lowest or highest seq number that matches the "block" variable. Also, add some whitespace and cleanup needless braces. Suggested-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-26dm writecache: remove unused member page_offset in writeback_structHuaisheng Ye1-2/+0
The stucture member page_offset in writeback_struct never has been used actually. Remove it. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-18dm writecache: add unlikely for returned value of rb_next/prevHuaisheng Ye1-2/+2
In functions writecache_discard() and writecache_find_entry() there is a high probablity that the pointer of structure rb_node won't equal NULL. Add unlikely for the pointer node NULL. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-18dm writecache: remove needless dereferences in __writecache_writeback_pmem()Huaisheng Ye1-6/+6
bio is already available so there is no need to access it in terms of the wb pointer. Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-03-05dm writecache: fix typo in name for writeback_wqHuaisheng Ye1-1/+1
The workqueue's name should be "writecache-writeback" instead of "writecache-writeabck". Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-12-18dm writecache: fix typo in error msg for creating writecache_flush_threadShenghui Wang1-1/+1
The error msg should be "flush thread" instead of "endio thread" for writecache_flush_thread. Signed-off-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-10-22dm writecache: remove disabled code in memory_entry()Mike Snitzer1-4/+1
This dead branch was missed during review. It only makes memory_entry() more inefficient due to needless call to is_power_of_2(), etc. Reported-by: shenghui <shhuiw@foxmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-08-26Merge tag 'libnvdimm-for-4.19_misc' of ↵Linus Torvalds1-2/+1
gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dave Jiang: "Collection of misc libnvdimm patches for 4.19 submission: - Adding support to read locked nvdimm capacity. - Change test code to make DSM failure code injection an override. - Add support for calculate maximum contiguous area for namespace. - Add support for queueing a short ARS when there is on going ARS for nvdimm. - Allow NULL to be passed in to ->direct_access() for kaddr and pfn params. - Improve smart injection support for nvdimm emulation testing. - Fix test code that supports for emulating controller temperature. - Fix hang on error before devm_memremap_pages() - Fix a bug that causes user memory corruption when data returned to user for ars_status. - Maintainer updates for Ross Zwisler emails and adding Jan Kara to fsdax" * tag 'libnvdimm-for-4.19_misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm: libnvdimm: fix ars_status output length calculation device-dax: avoid hang on error before devm_memremap_pages() tools/testing/nvdimm: improve emulation of smart injection filesystem-dax: Do not request kaddr and pfn when not required md/dm-writecache: Don't request pointer dummy_addr when not required dax/super: Do not request a pointer kaddr when not required tools/testing/nvdimm: kaddr and pfn can be NULL to ->direct_access() s390, dcssblk: kaddr and pfn can be NULL to ->direct_access() libnvdimm, pmem: kaddr and pfn can be NULL to ->direct_access() acpi/nfit: queue issuing of ars when an uc error notification comes in libnvdimm: Export max available extent libnvdimm: Use max contiguous area for namespace size MAINTAINERS: Add Jan Kara for filesystem DAX MAINTAINERS: update Ross Zwisler's email address tools/testing/nvdimm: Fix support for emulating controller temperature tools/testing/nvdimm: Make DSM failure code injection an override acpi, nfit: Prefer _DSM over _LSR for namespace label reads libnvdimm: Introduce locked DIMM capacity support
2018-08-16dm writecache: fix a crash due to reading past end of dirty_bitmapMikulas Patocka1-1/+1
wc->dirty_bitmap_size is in bytes so must multiply it by 8, not by BITS_PER_LONG, to get number of bitmap_bits. Fixes crash in find_next_bit() that was reported: https://bugzilla.kernel.org/show_bug.cgi?id=200819 Reported-by: edo.rus@gmail.com Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-07-30md/dm-writecache: Don't request pointer dummy_addr when not requiredHuaisheng Ye1-2/+1
Function persistent_memory_claim doesn't need to get local pointer dummy_addr from direct_access. Using NULL instead of having to pass in a useless local pointer that caller then just throw away. Suggested-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2018-07-27dm writecache: report start_sector in status lineMikulas Patocka1-1/+5
Fixes: d284f8248c7 ("dm writecache: support optional offset for start of device") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-07-02dm writecache: support optional offset for start of deviceMikulas Patocka1-14/+29
Add an optional parameter "start_sector" to allow the start of the device to be offset by the specified number of 512-byte sectors. The sectors below this offset are not used by the writecache device and are left to be used for disk labels and/or userspace metadata (e.g. lvm). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-22dm writecache: use 2-factor allocator argumentsKees Cook1-5/+5
This adjusts the allocator calls to use the 2-factor argument style, as already done treewide for better defense against allocator overflows. Signed-off-by: Kees Cook <keescook@chromium.org> [snitzer: tweaked code to leave assignment in a test alone] Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-08dm: add writecache targetMikulas Patocka1-0/+2305
The writecache target caches writes on persistent memory or SSD. It is intended for databases or other programs that need extremely low commit latency. The writecache target doesn't cache reads because reads are supposed to be cached in page cache in normal RAM. If persistent memory isn't available this target can still be used in SSD mode. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # fix missing goto Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> # fix compilation issue with !DAX Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> # use msecs_to_jiffies Acked-by: Dan Williams <dan.j.williams@intel.com> # reworks to unify ARM and x86 flushing Signed-off-by: Mike Snitzer <msnitzer@redhat.com>