# git rev-parse -q --verify 38e7571c07be01f9f19b355a9306a4e3d5cb0f5b^{commit} 38e7571c07be01f9f19b355a9306a4e3d5cb0f5b already have revision, skipping fetch # git checkout -q -f -B kisskb 38e7571c07be01f9f19b355a9306a4e3d5cb0f5b # git clean -qxdf # < git log -1 # commit 38e7571c07be01f9f19b355a9306a4e3d5cb0f5b # Merge: 80201fe175cb 21b4aa5d20fd # Author: Linus Torvalds # Date: Fri Mar 8 14:48:40 2019 -0800 # # Merge tag 'io_uring-2019-03-06' of git://git.kernel.dk/linux-block # # Pull io_uring IO interface from Jens Axboe: # "Second attempt at adding the io_uring interface. # # Since the first one, we've added basic unit testing of the three # system calls, that resides in liburing like the other unit tests that # we have so far. It'll take a while to get full coverage of it, but # we're working towards it. I've also added two basic test programs to # tools/io_uring. One uses the raw interface and has support for all the # various features that io_uring supports outside of standard IO, like # fixed files, fixed IO buffers, and polled IO. The other uses the # liburing API, and is a simplified version of cp(1). # # This adds support for a new IO interface, io_uring. # # io_uring allows an application to communicate with the kernel through # two rings, the submission queue (SQ) and completion queue (CQ) ring. # This allows for very efficient handling of IOs, see the v5 posting for # some basic numbers: # # https://lore.kernel.org/linux-block/20190116175003.17880-1-axboe@kernel.dk/ # # Outside of just efficiency, the interface is also flexible and # extendable, and allows for future use cases like the upcoming NVMe # key-value store API, networked IO, and so on. It also supports async # buffered IO, something that we've always failed to support in the # kernel. # # Outside of basic IO features, it supports async polled IO as well. # This particular feature has already been tested at Facebook months ago # for flash storage boxes, with 25-33% improvements. It makes polled IO # actually useful for real world use cases, where even basic flash sees # a nice win in terms of efficiency, latency, and performance. These # boxes were IOPS bound before, now they are not. # # This series adds three new system calls. One for setting up an # io_uring instance (io_uring_setup(2)), one for submitting/completing # IO (io_uring_enter(2)), and one for aux functions like registrating # file sets, buffers, etc (io_uring_register(2)). Through the help of # Arnd, I've coordinated the syscall numbers so merge on that front # should be painless. # # Jon did a writeup of the interface a while back, which (except for # minor details that have been tweaked) is still accurate. Find that # here: # # https://lwn.net/Articles/776703/ # # Huge thanks to Al Viro for helping getting the reference cycle code # correct, and to Jann Horn for his extensive reviews focused on both # security and bugs in general. # # There's a userspace library that provides basic functionality for # applications that don't need or want to care about how to fiddle with # the rings directly. It has helpers to allow applications to easily set # up an io_uring instance, and submit/complete IO through it without # knowing about the intricacies of the rings. It also includes man pages # (thanks to Jeff Moyer), and will continue to grow support helper # functions and features as time progresses. Find it here: # # git://git.kernel.dk/liburing # # Fio has full support for the raw interface, both in the form of an IO # engine (io_uring), but also with a small test application (t/io_uring) # that can exercise and benchmark the interface" # # * tag 'io_uring-2019-03-06' of git://git.kernel.dk/linux-block: # io_uring: add a few test tools # io_uring: allow workqueue item to handle multiple buffered requests # io_uring: add support for IORING_OP_POLL # io_uring: add io_kiocb ref count # io_uring: add submission polling # io_uring: add file set registration # net: split out functions related to registering inflight socket files # io_uring: add support for pre-mapped user IO buffers # block: implement bio helper to add iter bvec pages to bio # io_uring: batch io_kiocb allocation # io_uring: use fget/fput_many() for file references # fs: add fget_many() and fput_many() # io_uring: support for IO polling # io_uring: add fsync support # Add io_uring IO interface # < /opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux-gcc --version # < /opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux-ld --version # < git log --format=%s --max-count=1 38e7571c07be01f9f19b355a9306a4e3d5cb0f5b # < make -s -j 80 ARCH=xtensa O=/kisskb/build/linus_xtensa-allmodconfig_xtensa CROSS_COMPILE=/opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux- allmodconfig # Added to kconfig CONFIG_BUILD_DOCSRC=n # Added to kconfig CONFIG_MODULE_SIG=n # Added to kconfig CONFIG_SAMPLES=n # yes \n | make -s -j 80 ARCH=xtensa O=/kisskb/build/linus_xtensa-allmodconfig_xtensa CROSS_COMPILE=/opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux- oldconfig yes: standard output: Broken pipe # make -s -j 80 ARCH=xtensa O=/kisskb/build/linus_xtensa-allmodconfig_xtensa CROSS_COMPILE=/opt/cross/kisskb/br-xtensa-full-2016.08-613-ge98b4dd/bin/xtensa-linux- :1478:2: warning: #warning syscall io_uring_setup not implemented [-Wcpp] :1481:2: warning: #warning syscall io_uring_enter not implemented [-Wcpp] :1484:2: warning: #warning syscall io_uring_register not implemented [-Wcpp] /kisskb/src/arch/xtensa/kernel/pci.c:45:32: warning: 'pci_ctrl_tail' defined but not used [-Wunused-variable] static struct pci_controller **pci_ctrl_tail = &pci_ctrl_head; ^ ./usr/include/asm/setup.h:17: userspace cannot reference function or variable defined in the kernel /kisskb/src/drivers/char/tpm/tpm2-cmd.c: In function 'tpm2_unseal_trusted': /kisskb/src/drivers/char/tpm/tpm2-cmd.c:668:2: warning: 'blob_handle' may be used uninitialized in this function [-Wmaybe-uninitialized] tpm2_flush_context_cmd(chip, blob_handle, TPM_TRANSMIT_UNLOCKED); ^ In file included from /kisskb/src/arch/xtensa/include/asm/atomic.h:21:0, from /kisskb/src/include/linux/atomic.h:7, from /kisskb/src/include/asm-generic/bitops/atomic.h:5, from /kisskb/src/arch/xtensa/include/asm/bitops.h:222, from /kisskb/src/include/linux/bitops.h:19, from /kisskb/src/include/linux/kernel.h:12, from /kisskb/src/include/linux/list.h:9, from /kisskb/src/include/linux/wait.h:7, from /kisskb/src/include/linux/wait_bit.h:8, from /kisskb/src/include/linux/fs.h:6, from /kisskb/src/fs/ocfs2/file.c:27: /kisskb/src/fs/ocfs2/file.c: In function 'ocfs2_file_write_iter': /kisskb/src/arch/xtensa/include/asm/cmpxchg.h:140:3: warning: value computed is not used [-Wunused-value] ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) ^ /kisskb/src/fs/ocfs2/file.c:2386:3: note: in expansion of macro 'xchg' xchg(&iocb->ki_complete, saved_ki_complete); ^ /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr': /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:399:26: warning: 'data' may be used uninitialized in this function [-Wmaybe-uninitialized] pd->msg->buf[real_pos] = data; ^ /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:372:16: note: 'data' was declared here unsigned char data; ^ /kisskb/src/drivers/i2c/i2c-core-base.c: In function 'i2c_generic_scl_recovery': /kisskb/src/drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized] if (ret == -EOPNOTSUPP) ^ /kisskb/src/drivers/input/joystick/analog.c:172:2: warning: #warning Precise timer not defined for this architecture. [-Wcpp] #warning Precise timer not defined for this architecture. ^ In file included from /kisskb/src/include/linux/rwsem.h:16:0, from /kisskb/src/include/linux/notifier.h:15, from /kisskb/src/include/linux/clk.h:17, from /kisskb/src/drivers/tty/serial/sh-sci.c:24: /kisskb/src/drivers/tty/serial/sh-sci.c: In function 'sci_dma_rx_submit': /kisskb/src/include/linux/spinlock.h:279:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized] _raw_spin_unlock_irqrestore(lock, flags); \ ^ /kisskb/src/drivers/tty/serial/sh-sci.c:1363:16: note: 'flags' was declared here unsigned long flags; ^ In file included from ./arch/xtensa/include/generated/asm/div64.h:1:0, from /kisskb/src/include/linux/kernel.h:18, from /kisskb/src/include/linux/skbuff.h:17, from /kisskb/src/include/linux/if_ether.h:23, from /kisskb/src/include/linux/etherdevice.h:25, from /kisskb/src/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c:62: /kisskb/src/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c: In function 'iwl_mvm_debug_range_resp': /kisskb/src/include/asm-generic/div64.h:222:28: warning: comparison of distinct pointer types lacks a cast (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \ ^ /kisskb/src/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c:465:2: note: in expansion of macro 'do_div' do_div(rtt_avg, 6666); ^ In file included from /kisskb/src/arch/xtensa/include/asm/atomic.h:21:0, from /kisskb/src/include/linux/atomic.h:7, from /kisskb/src/include/asm-generic/bitops/atomic.h:5, from /kisskb/src/arch/xtensa/include/asm/bitops.h:222, from /kisskb/src/include/linux/bitops.h:19, from /kisskb/src/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c:11: /kisskb/src/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c: In function 'ixgbevf_xdp_setup': /kisskb/src/arch/xtensa/include/asm/cmpxchg.h:140:3: warning: value computed is not used [-Wunused-value] ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) ^ /kisskb/src/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c:4471:4: note: in expansion of macro 'xchg' xchg(&adapter->rx_ring[i]->xdp_prog, adapter->xdp_prog); ^ Completed OK # rm -rf /kisskb/build/linus_xtensa-allmodconfig_xtensa # Build took: 0:11:07.925286