- 01 Dec, 2020 1 commit
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Daniel Borkmann authored
Stephen reported the following build error for !CONFIG_NET_RX_BUSY_POLL built kernels: In file included from fs/select.c:32: include/net/busy_poll.h: In function 'sk_mark_napi_id_once': include/net/busy_poll.h:150:36: error: 'const struct sk_buff' has no member named 'napi_id' 150 | __sk_mark_napi_id_once_xdp(sk, skb->napi_id); | ^~ Fix it by wrapping a CONFIG_NET_RX_BUSY_POLL around the helpers. Fixes: b02e5a0e ("xsk: Propagate napi_id to XDP socket Rx path") Reported-by:Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Cc: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/linux-next/20201201190746.7d3357fb@canb.auug.org.au
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- 30 Nov, 2020 12 commits
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Daniel Borkmann authored
Björn Töpel says: ==================== This series introduces three new features: 1. A new "heavy traffic" busy-polling variant that works in concert with the existing napi_defer_hard_irqs and gro_flush_timeout knobs. 2. A new socket option that let a user change the busy-polling NAPI budget. 3. Allow busy-polling to be performed on XDP sockets. The existing busy-polling mode, enabled by the SO_BUSY_POLL socket option or system-wide using the /proc/sys/net/core/busy_read knob, is an opportunistic. That means that if the NAPI context is not scheduled, it will poll it. If, after busy-polling, the budget is exceeded the busy-polling logic will schedule the NAPI onto the regular softirq handling. One implication of the behavior above is that a busy/heavy loaded NAPI context will never enter/allow for busy-polling. Some applications prefer that most NAPI processing would be done by busy-polling. This series adds a new socket option, SO_PREFER_BUSY_POLL, that works in concert with the napi_defer_hard_irqs and gro_flush_timeout knobs. The napi_defer_hard_irqs and gro_flush_timeout knobs were introduced in commit 6f8b12d6 ("net: napi: add hard irqs deferral feature"), and allows for a user to defer interrupts to be enabled and instead schedule the NAPI context from a watchdog timer. When a user enables the SO_PREFER_BUSY_POLL, again with the other knobs enabled, and the NAPI context is being processed by a softirq, the softirq NAPI processing will exit early to allow the busy-polling to be performed. If the application stops performing busy-polling via a system call, the watchdog timer defined by gro_flush_timeout will timeout, and regular softirq handling will resume. In summary; Heavy traffic applications that prefer busy-polling over softirq processing should use this option. Patch 6 touches a lot of drivers, so the Cc: list is grossly long. Example usage: $ echo 2 | sudo tee /sys/class/net/ens785f1/napi_defer_hard_irqs $ echo 200000 | sudo tee /sys/class/net/ens785f1/gro_flush_timeout Note that the timeout should be larger than the userspace processing window, otherwise the watchdog will timeout and fall back to regular softirq processing. Enable the SO_BUSY_POLL/SO_PREFER_BUSY_POLL options on your socket. Performance simple UDP ping-pong: A packet generator blasts UDP packets from a packet generator to a certain {src,dst}IP/port, so a dedicated ksoftirq will be busy handling the packets at a certain core. A simple UDP test program that simply does recvfrom/sendto is running at the host end. Throughput in pps and RTT latency is measured at the packet generator. /proc/sys/net/core/busy_read is set (20). Min Max Avg (usec) 1. Blocking 2-cores: 490Kpps 1218.192 1335.427 1271.083 2. Blocking, 1-core: 155Kpps 1327.195 17294.855 4761.367 3. Non-blocking, 2-cores: 475Kpps 1221.197 1330.465 1270.740 4. Non-blocking, 1-core: 3Kpps 29006.482 37260.465 33128.367 5. Non-blocking, prefer busy-poll, 1-core: 420Kpps 1202.535 5494.052 4885.443 Scenario 2 and 5 shows when the new option should be used. Throughput go from 155 to 420Kpps, average latency are similar, but the tail latencies are much better for the latter. Performance XDP sockets: Again, a packet generator blasts UDP packets from a packet generator to a certain {src,dst}IP/port. Today, running XDP sockets sample on the same core as the softirq handling, performance tanks mainly because we do not yield to user-space when the XDP socket Rx queue is full. # taskset -c 5 ./xdpsock -i ens785f1 -q 5 -n 1 -r Rx: 64Kpps # # preferred busy-polling, budget 8 # taskset -c 5 ./xdpsock -i ens785f1 -q 5 -n 1 -r -B -b 8 Rx 9.9Mpps # # preferred busy-polling, budget 64 # taskset -c 5 ./xdpsock -i ens785f1 -q 5 -n 1 -r -B -b 64 Rx: 19.3Mpps # # preferred busy-polling, budget 256 # taskset -c 5 ./xdpsock -i ens785f1 -q 5 -n 1 -r -B -b 256 Rx: 21.4Mpps # # preferred busy-polling, budget 512 # taskset -c 5 ./xdpsock -i ens785f1 -q 5 -n 1 -r -B -b 512 Rx: 21.7Mpps Compared to the two-core case: # taskset -c 4 ./xdpsock -i ens785f1 -q 20 -n 1 -r Rx: 20.7Mpps We're getting better single-core performance than two, for this naïve drop scenario. Performance netperf UDP_RR: Note that netperf UDP_RR is not a heavy traffic tests, and preferred busy-polling is not typically something we want to use here. $ echo 20 | sudo tee /proc/sys/net/core/busy_read $ netperf -H 192.168.1.1 -l 30 -t UDP_RR -v 2 -- \ -o min_latency,mean_latency,max_latency,stddev_latency,transaction_rate busy-polling blocking sockets: 12,13.33,224,0.63,74731.177 I hacked netperf to use non-blocking sockets and re-ran: busy-polling non-blocking sockets: 12,13.46,218,0.72,73991.172 prefer busy-polling non-blocking sockets: 12,13.62,221,0.59,73138.448 Using the preferred busy-polling mode does not impact performance. The above tests was done for the 'ice' driver. Thanks to Jakub for suggesting this busy-polling addition [1], and Eric for all input/review! Changes: rfc-v1 [2] -> rfc-v2: * Changed name from bias to prefer. * Base the work on Eric's/Luigi's defer irq/gro timeout work. * Proper GRO flushing. * Build issues for some XDP drivers. rfc-v2 [3] -> v1: * Fixed broken qlogic build. * Do not trigger an IPI (XDP socket wakeup) when busy-polling is enabled. v1 [4] -> v2: * Added napi_id to socionext driver, and added Ilias Acked-by:. (Ilias) * Added a samples patch to improve busy-polling for xdpsock/l2fwd. * Correctly mark atomic operations with {WRITE,READ}_ONCE, to make KCSAN and the code readers happy. (Eric) * Check NAPI budget not to exceed U16_MAX. (Eric) * Added kdoc. v2 [5] -> v3: * Collected Acked-by. * Check NAPI disable prior prefer busy-polling. (Jakub) * Added napi_id registration for virtio-net. (Michael) * Added napi_id registration for veth. v3 [6] -> v4: * Collected Acked-by/Reviewed-by. [1] https://lore.kernel.org/netdev/20200925120652.10b8d7c5@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com/ [2] https://lore.kernel.org/bpf/20201028133437.212503-1-bjorn.topel@gmail.com/ [3] https://lore.kernel.org/bpf/20201105102812.152836-1-bjorn.topel@gmail.com/ [4] https://lore.kernel.org/bpf/20201112114041.131998-1-bjorn.topel@gmail.com/ [5] https://lore.kernel.org/bpf/20201116110416.10719-1-bjorn.topel@gmail.com/ [6] https://lore.kernel.org/bpf/20201119083024.119566-1-bjorn.topel@gmail.com/ ==================== Signed-off-by:
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Björn Töpel authored
Support for the SO_BUSY_POLL_BUDGET setsockopt, via the batching option ('b'). Signed-off-by:Björn Töpel <bjorn.topel@intel.com> Signed-off-by:
Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20201130185205.196029-11-bjorn.topel@gmail.com
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Björn Töpel authored
Add a new option to xdpsock, 'B', for busy-polling. This option will also set the batching size, 'b' option, to the busy-poll budget. Signed-off-by:
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Björn Töpel authored
Start using recvfrom() the l2fwd scenario, instead of poll() which is more expensive and need additional knobs for busy-polling. Signed-off-by:
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Björn Töpel authored
Start using recvfrom() the rxdrop scenario. Signed-off-by:
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Björn Töpel authored
Add napi_id to the xdp_rxq_info structure, and make sure the XDP socket pick up the napi_id in the Rx path. The napi_id is used to find the corresponding NAPI structure for socket busy polling. Signed-off-by:
Ilias Apalodimas <ilias.apalodimas@linaro.org> Acked-by:
Michael S. Tsirkin <mst@redhat.com> Acked-by:
Tariq Toukan <tariqt@nvidia.com> Link: https://lore.kernel.org/bpf/20201130185205.196029-7-bjorn.topel@gmail.com
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Björn Töpel authored
Wire-up XDP socket busy-poll support for recvmsg() and sendmsg(). If the XDP socket prefers busy-polling, make sure that no wakeup/IPI is performed. Signed-off-by:
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Björn Töpel authored
Add a check for need wake up in sendmsg(), so that if a user calls sendmsg() when no wakeup is needed, do not trigger a wakeup. To simplify the need wakeup check in the syscall, unconditionally enable the need wakeup flag for Tx. This has a side-effect for poll(); If poll() is called for a socket without enabled need wakeup, a Tx wakeup is unconditionally performed. The wakeup matrix for AF_XDP now looks like: need wakeup | poll() | sendmsg() | recvmsg() ------------+--------------+-------------+------------ disabled | wake Tx | wake Tx | nop enabled | check flag; | check flag; | check flag; | wake Tx/Rx | wake Tx | wake Rx Signed-off-by: -
Björn Töpel authored
Add support for non-blocking recvmsg() to XDP sockets. Previously, only sendmsg() was supported by XDP socket. Now, for symmetry and the upcoming busy-polling support, recvmsg() is added. Signed-off-by:
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Björn Töpel authored
This option lets a user set a per socket NAPI budget for busy-polling. If the options is not set, it will use the default of 8. Signed-off-by:
Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/bpf/20201130185205.196029-3-bjorn.topel@gmail.com
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Björn Töpel authored
The existing busy-polling mode, enabled by the SO_BUSY_POLL socket option or system-wide using the /proc/sys/net/core/busy_read knob, is an opportunistic. That means that if the NAPI context is not scheduled, it will poll it. If, after busy-polling, the budget is exceeded the busy-polling logic will schedule the NAPI onto the regular softirq handling. One implication of the behavior above is that a busy/heavy loaded NAPI context will never enter/allow for busy-polling. Some applications prefer that most NAPI processing would be done by busy-polling. This series adds a new socket option, SO_PREFER_BUSY_POLL, that works in concert with the napi_defer_hard_irqs and gro_flush_timeout knobs. The napi_defer_hard_irqs and gro_flush_timeout knobs were introduced in commit 6f8b12d6 ("net: napi: add hard irqs deferral feature"), and allows for a user to defer interrupts to be enabled and instead schedule the NAPI context from a watchdog timer. When a user enables the SO_PREFER_BUSY_POLL, again with the other knobs enabled, and the NAPI context is being processed by a softirq, the softirq NAPI processing will exit early to allow the busy-polling to be performed. If the application stops performing busy-polling via a system call, the watchdog timer defined by gro_flush_timeout will timeout, and regular softirq handling will resume. In summary; Heavy traffic applications that prefer busy-polling over softirq processing should use this option. Example usage: $ echo 2 | sudo tee /sys/class/net/ens785f1/napi_defer_hard_irqs $ echo 200000 | sudo tee /sys/class/net/ens785f1/gro_flush_timeout Note that the timeout should be larger than the userspace processing window, otherwise the watchdog will timeout and fall back to regular softirq processing. Enable the SO_BUSY_POLL/SO_PREFER_BUSY_POLL options on your socket. Signed-off-by:
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KP Singh authored
Flavored variants of test_progs (e.g. test_progs-no_alu32) change their working directory to the corresponding subdirectory (e.g. no_alu32). Since the setup script required by test_ima (ima_setup.sh) is not mentioned in the dependencies, it does not get copied to these subdirectories and causes flavored variants of test_ima to fail. Adding the script to TRUNNER_EXTRA_FILES ensures that the file is also copied to the subdirectories for the flavored variants of test_progs. Fixes: 34b82d3a ("bpf: Add a selftest for bpf_ima_inode_hash") Reported-by:
Yonghong Song <yhs@fb.com> Suggested-by:
KP Singh <kpsingh@google.com> Signed-off-by:
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- 27 Nov, 2020 10 commits
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Zhu Yanjun authored
The functions xsk_map_put() and xsk_map_inc() are simple wrappers and as such, replace these functions with the functions bpf_map_inc() and bpf_map_put() and remove some error testing code. Signed-off-by:
Zhu Yanjun <zyjzyj2000@gmail.com> Signed-off-by:
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Magnus Karlsson authored
Replace size_t with __u32 in the xsk interfaces that contain this. There is no reason to have size_t since the internal variable that is manipulated is a __u32. The following APIs are affected: __u32 xsk_ring_prod__reserve(struct xsk_ring_prod *prod, __u32 nb, __u32 *idx) void xsk_ring_prod__submit(struct xsk_ring_prod *prod, __u32 nb) __u32 xsk_ring_cons__peek(struct xsk_ring_cons *cons, __u32 nb, __u32 *idx) void xsk_ring_cons__cancel(struct xsk_ring_cons *cons, __u32 nb) void xsk_ring_cons__release(struct xsk_ring_cons *cons, __u32 nb) The "nb" variable and the return values have been changed from size_t to __u32. Signed-off-by:
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Andrii Nakryiko authored
"Daniel T. says: ==================== Numerous refactoring that rewrites BPF programs written with bpf_load to use the libbpf loader was finally completed, resulting in BPF programs using bpf_load within the kernel being completely no longer present. This patchset refactors remaining bpf programs with libbpf and completely removes bpf_load, an outdated bpf loader that is difficult to keep up with the latest kernel BPF and causes confusion. Changes in v2: - drop 'move tracing helpers to trace_helper' patch - add link pinning to prevent cleaning up on process exit - add static at global variable and remove unused variable - change to destroy link even after link__pin() - fix return error code on exit - merge commit with changing Makefile Changes in v3: - cleanup bpf_link, bpf_object and cgroup fd both on success and error ==================== Signed-off-by:Andrii Nakryiko <andrii@kernel.org>
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Daniel T. Lee authored
Numerous refactoring that rewrites BPF programs written with bpf_load to use the libbpf loader was finally completed, resulting in BPF programs using bpf_load within the kernel being completely no longer present. This commit removes bpf_load, an outdated bpf loader that is difficult to keep up with the latest kernel BPF and causes confusion. Also, this commit removes the unused trace_helper and bpf_load from samples/bpf target objects from Makefile. Signed-off-by:
Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by:
Jesper Dangaard Brouer <brouer@redhat.com> Acked-by:
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Daniel T. Lee authored
Currently, lwt_len_hist's map lwt_len_hist_map is uses pinning, and the map isn't cleared on test end. This leds to reuse of that map for each test, which prevents the results of the test from being accurate. This commit fixes the problem by removing of pinned map from bpffs. Also, this commit add the executable permission to shell script files. Fixes: f74599f7 ("bpf: Add tests and samples for LWT-BPF") Signed-off-by:
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Daniel T. Lee authored
This commit refactors the existing program with libbpf bpf loader. Since the kprobe, tracepoint and raw_tracepoint bpf program can be attached with single bpf_program__attach() interface, so the corresponding function of libbpf is used here. Rather than specifying the number of cpus inside the code, this commit uses the number of available cpus with _SC_NPROCESSORS_ONLN. Signed-off-by:
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Daniel T. Lee authored
This commit refactors the existing ibumad program with libbpf bpf loader. Attach/detach of Tracepoint bpf programs has been managed with the generic bpf_program__attach() and bpf_link__destroy() from the libbpf. Also, instead of using the previous BPF MAP definition, this commit refactors ibumad MAP definition with the new BTF-defined MAP format. To verify that this bpf program works without an infiniband device, try loading ib_umad kernel module and test the program as follows: # modprobe ib_umad # ./ibumad Moreover, TRACE_HELPERS has been removed from the Makefile since it is not used on this program. Signed-off-by: -
Daniel T. Lee authored
This commit refactors the existing kprobe program with libbpf bpf loader. To attach bpf program, this uses generic bpf_program__attach() approach rather than using bpf_load's load_bpf_file(). To attach bpf to perf_event, instead of using previous ioctl method, this commit uses bpf_program__attach_perf_event since it manages the enable of perf_event and attach of BPF programs to it, which is much more intuitive way to achieve. Also, explicit close(fd) has been removed since event will be closed inside bpf_link__destroy() automatically. Furthermore, to prevent conflict of same named uprobe events, O_TRUNC flag has been used to clear 'uprobe_events' interface. Signed-off-by:
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Daniel T. Lee authored
This commit refactors the existing cgroup program with libbpf bpf loader. The original test_cgrp2_sock2 has keeped the bpf program attached to the cgroup hierarchy even after the exit of user program. To implement the same functionality with libbpf, this commit uses the BPF_LINK_PINNING to pin the link attachment even after it is closed. Since this uses LINK instead of ATTACH, detach of bpf program from cgroup with 'test_cgrp2_sock' is not used anymore. The code to mount the bpf was added to the .sh file in case the bpff was not mounted on /sys/fs/bpf. Additionally, to fix the problem that shell script cannot find the binary object from the current path, relative path './' has been added in front of binary. Fixes: 554ae6e7 ("samples/bpf: add userspace example for prohibiting sockets") Signed-off-by:
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Daniel T. Lee authored
This commit refactors the existing cgroup programs with libbpf bpf loader. Since bpf_program__attach doesn't support cgroup program attachment, this explicitly attaches cgroup bpf program with bpf_program__attach_cgroup(bpf_prog, cg1). Also, to change attach_type of bpf program, this uses libbpf's bpf_program__set_expected_attach_type helper to switch EGRESS to INGRESS. To keep bpf program attached to the cgroup hierarchy even after the exit, this commit uses the BPF_LINK_PINNING to pin the link attachment even after it is closed. Besides, this program was broken due to the typo of BPF MAP definition. But this commit solves the problem by fixing this from 'queue_stats' map struct hvm_queue_stats -> hbm_queue_stats. Fixes: 36b5d471 ("selftests/bpf: samples/bpf: Split off legacy stuff from bpf_helpers.h") Signed-off-by:
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- 25 Nov, 2020 6 commits
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Andrei Matei authored
Before this patch, profiler.inc.h wouldn't compile with clang-11 (before the __builtin_preserve_enum_value LLVM builtin was introduced in https://reviews.llvm.org/D83242). Another test that uses this builtin (test_core_enumval) is conditionally skipped if the compiler is too old. In that spirit, this patch inhibits part of populate_cgroup_info(), which needs this CO-RE builtin. The selftests build again on clang-11. The affected test (the profiler test) doesn't pass on clang-11 because it's missing https://reviews.llvm.org/D85570, but at least the test suite as a whole compiles. The test's expected failure is already called out in the README. Signed-off-by:
Andrei Matei <andreimatei1@gmail.com> Signed-off-by:
Florian Lehner <dev@der-flo.net> Acked-by:
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KP Singh authored
The test does the following: - Mounts a loopback filesystem and appends the IMA policy to measure executions only on this file-system. Restricting the IMA policy to a particular filesystem prevents a system-wide IMA policy change. - Executes an executable copied to this loopback filesystem. - Calls the bpf_ima_inode_hash in the bprm_committed_creds hook and checks if the call succeeded and checks if a hash was calculated. The test shells out to the added ima_setup.sh script as the setup is better handled in a shell script and is more complicated to do in the test program or even shelling out individual commands from C. The list of required configs (i.e. IMA, SECURITYFS, IMA_{WRITE,READ}_POLICY) for running this test are also updated. Suggested-by: Mimi Zohar <zohar@linux.ibm.com> (limit policy rule to loopback mount) Signed-off-by: -
KP Singh authored
Provide a wrapper function to get the IMA hash of an inode. This helper is useful in fingerprinting files (e.g executables on execution) and using these fingerprints in detections like an executable unlinking itself. Since the ima_inode_hash can sleep, it's only allowed for sleepable LSM hooks. Signed-off-by:
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KP Singh authored
This is in preparation to add a helper for BPF LSM programs to use IMA hashes when attached to LSM hooks. There are LSM hooks like inode_unlink which do not have a struct file * argument and cannot use the existing ima_file_hash API. An inode based API is, therefore, useful in LSM based detections like an executable trying to delete itself which rely on the inode_unlink LSM hook. Moreover, the ima_file_hash function does nothing with the struct file pointer apart from calling file_inode on it and converting it to an inode. Signed-off-by:
Mimi Zohar <zohar@linux.ibm.com> Link: https://lore.kernel.org/bpf/20201124151210.1081188-2-kpsingh@chromium.org
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Li RongQing authored
Add a new function for returning descriptors the user received after an xsk_ring_cons__peek call. After the application has gotten a number of descriptors from a ring, it might not be able to or want to process them all for various reasons. Therefore, it would be useful to have an interface for returning or cancelling a number of them so that they are returned to the ring. This patch adds a new function called xsk_ring_cons__cancel that performs this operation on nb descriptors counted from the end of the batch of descriptors that was received through the peek call. Signed-off-by:
Li RongQing <lirongqing@baidu.com> Signed-off-by:
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Wedson Almeida Filho authored
The current implementation uses a number of gotos to implement a loop and different paths within the loop, which makes the code less readable than it would be with an explicit while-loop. This patch also replaces a chain of if/if-elses keyed on the same expression with a switch statement. No change in behaviour is intended. Signed-off-by:
Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by:
Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201121015509.3594191-1-wedsonaf@google.com
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- 24 Nov, 2020 4 commits
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Andrii Nakryiko authored
Given .BTF section is not allocatable, it will get trimmed after module is loaded. BPF system handles that properly by creating an independent copy of data. But prevent any accidental misused by resetting the pointer to BTF data. Fixes: 36e68442 ("bpf: Load and verify kernel module BTFs") Suggested-by:
Jessica Yu <jeyu@kernel.org> Signed-off-by:
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Andrii Nakryiko authored
In some modes of operation, Kbuild allows to build modules without having vmlinux image around. In such case, generation of module BTF is impossible. This patch changes the behavior to emit a warning about impossibility of generating kernel module BTF, instead of breaking the build. This is especially important for out-of-tree external module builds. In vmlinux-less mode: $ make clean $ make modules_prepare $ touch drivers/acpi/button.c $ make M=drivers/acpi ... CC [M] drivers/acpi/button.o MODPOST drivers/acpi/Module.symvers LD [M] drivers/acpi/button.ko BTF [M] drivers/acpi/button.ko Skipping BTF generation for drivers/acpi/button.ko due to unavailability of vmlinux ... $ readelf -S ~/linux-build/default/drivers/acpi/button.ko | grep BTF -A1 ... empty ... Now with normal build: $ make all ... LD [M] drivers/acpi/button.ko BTF [M] drivers/acpi/button.ko ... $ readelf -S ~/linux-build/default/drivers/acpi/button.ko | grep BTF -A1 [60] .BTF PROGBITS 0000000000000000 00029310 000000000000ab3f 0000000000000000 0 0 1 Fixes: 5f9ae91f ("kbuild: Build kernel module BTFs if BTF is enabled and pahole supports it") Reported-by:Bruce Allan <bruce.w.allan@intel.com> Signed-off-by:
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Andrei Matei authored
A couple of places in the readme had invalid rst formatting causing the rendering to be off. This patch fixes them with minimal edits. Signed-off-by:
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Andrei Matei authored
The link was bad because of invalid rst; it was pointing to itself and was rendering badly. Signed-off-by:
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- 20 Nov, 2020 2 commits
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Song Liu authored
Simplify task_file_seq_get_next() by removing two in/out arguments: task and fstruct. Use info->task and info->files instead. Signed-off-by:
Song Liu <songliubraving@fb.com> Signed-off-by:
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Yonghong Song authored
Commit 47c09d6a("bpftool: Introduce "prog profile" command") introduced "bpftool prog profile" command which can be used to profile bpf program with metrics like # of instructions, This patch added support for itlb_misses and dtlb_misses. During an internal bpf program performance evaluation, I found these two metrics are also very useful. The following is an example output: $ bpftool prog profile id 324 duration 3 cycles itlb_misses 1885029 run_cnt 5134686073 cycles 306893 itlb_misses $ bpftool prog profile id 324 duration 3 cycles dtlb_misses 1827382 run_cnt 4943593648 cycles 5975636 dtlb_misses $ bpftool prog profile id 324 duration 3 cycles llc_misses 1836527 run_cnt 5019612972 cycles 4161041 llc_misses From the above, we can see quite some dtlb misses, 3 dtlb misses perf prog run. This might be something worth further investigation. Signed-off-by:
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- 19 Nov, 2020 4 commits
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Andrii Nakryiko authored
Björn Töpel says: ==================== This series contain some fixes for selftests/bpf when building/running on a RISC-V host. Details can be found in each individual commit. v2: Makefile cosmetics. (Andrii) Simplified unpriv check and added comment. (Andrii) ==================== Signed-off-by: -
Björn Töpel authored
A lot of tests require unaligned memory access to work. Mark the tests as such, so that they can be avoided on unsupported architectures such as RISC-V. Signed-off-by:
Björn Töpel <bjorn.topel@gmail.com> Signed-off-by:
Luke Nelson <luke.r.nels@gmail.com> Link: https://lore.kernel.org/bpf/20201118071640.83773-4-bjorn.topel@gmail.com
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Björn Töpel authored
Some architectures have strict alignment requirements. In that case, the BPF verifier detects if a program has unaligned accesses and rejects them. A user can pass BPF_F_ANY_ALIGNMENT to a program to override this check. That, however, will only work when a privileged user loads a program. An unprivileged user loading a program with this flag will be rejected prior entering the verifier. Hence, it does not make sense to load unprivileged programs without strict alignment when testing the verifier. This patch avoids exactly that. Signed-off-by:
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Björn Töpel authored
The selftests/bpf Makefile includes system include directories from the host, when building BPF programs. On RISC-V glibc requires that __riscv_xlen is defined. This is not the case for "clang -target bpf", which messes up __WORDSIZE (errno.h -> ... -> wordsize.h) and breaks the build. By explicitly defining __risc_xlen correctly for riscv, we can workaround this. Fixes: 167381f3 ("selftests/bpf: Makefile fix "missing" headers on build with -idirafter") Signed-off-by:
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- 18 Nov, 2020 1 commit
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Dmitrii Banshchikov authored
The helper uses CLOCK_MONOTONIC_COARSE source of time that is less accurate but more performant. We have a BPF CGROUP_SKB firewall that supports event logging through bpf_perf_event_output(). Each event has a timestamp and currently we use bpf_ktime_get_ns() for it. Use of bpf_ktime_get_coarse_ns() saves ~15-20 ns in time required for event logging. bpf_ktime_get_ns(): EgressLogByRemoteEndpoint 113.82ns 8.79M bpf_ktime_get_coarse_ns(): EgressLogByRemoteEndpoint 95.40ns 10.48M Signed-off-by:
Dmitrii Banshchikov <me@ubique.spb.ru> Signed-off-by:
Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201117184549.257280-1-me@ubique.spb.ru
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