- Nov 30, 2020
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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:
Björn Töpel <bjorn.topel@intel.com> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Reviewed-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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- Nov 27, 2020
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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:
Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/1606402998-12562-1-git-send-email-yanjunz@nvidia.com
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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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- Nov 25, 2020
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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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- Nov 24, 2020
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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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- Nov 20, 2020
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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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- Nov 19, 2020
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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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- Nov 18, 2020
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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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KP Singh authored
The test forks a child process, updates the local storage to set/unset the securexec bit. The BPF program in the test attaches to bprm_creds_for_exec which checks the local storage of the current task to set the secureexec bit on the binary parameters (bprm). The child then execs a bash command with the environment variable TMPDIR set in the envp. The bash command returns a different exit code based on its observed value of the TMPDIR variable. Since TMPDIR is one of the variables that is ignored by the dynamic loader when the secureexec bit is set, one should expect the child execution to not see this value when the secureexec bit is set. Signed-off-by:
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KP Singh authored
The helper allows modification of certain bits on the linux_binprm struct starting with the secureexec bit which can be updated using the BPF_F_BPRM_SECUREEXEC flag. secureexec can be set by the LSM for privilege gaining executions to set the AT_SECURE auxv for glibc. When set, the dynamic linker disables the use of certain environment variables (like LD_PRELOAD). Signed-off-by:
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- Nov 17, 2020
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Daniel Borkmann authored
Magnus Karlsson says: ==================== This patch set improves the performance of mainly the Tx processing of AF_XDP sockets. Though, patch 3 also improves the Rx path. All in all, this patch set improves the throughput of the l2fwd xdpsock application by around 11%. If we just take a look at Tx processing part, it is improved by 35% to 40%. Hopefully the new batched Tx interfaces should be of value to other drivers implementing AF_XDP zero-copy support. But patch #3 is generic and will improve performance of all drivers when using AF_XDP sockets (under the premises explained in that patch). @daniel. In patch 3, I apply all the padding required to hinder the adjacency prefetcher to prefetch the wrong things. After this patch set, I will submit another patch set that introduces ____cacheline_padding_in_smp in include/linux/cache.h according to your suggestions. The last patch in that patch set will then convert the explicit paddings that we have now to ____cacheline_padding_in_smp. v2 -> v3: * Fixed #pragma warning with clang and defined a loop_unrolled_for macro for easier readability [lkp, Nick] * Simplified invalid descriptor handling in xskq_cons_read_desc_batch() v1 -> v2: * Removed added parameter in i40e_setup_tx_descriptors and adopted a simpler solution [Maciej] * Added test for !xs in xsk_tx_peek_release_desc_batch() [John] * Simplified return path in xsk_tx_peek_release_desc_batch() [John] * Dropped patch #1 in v1 that introduced lazy completions. Hopefully this is not needed when we get busy poll [Jakub] * Iterate over local variable in xskq_prod_reserve_addr_batch() for improved performance * Fixed the fallback path in xsk_tx_peek_release_desc_batch() so that it also produces a batch of descriptors, albeit by using the slower (but more general) older code. This improves the performance of the case when multiple sockets are sharing the same device and queue id. ==================== Signed-off-by:
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Magnus Karlsson authored
Use the new batched xsk interfaces for the Tx path in the i40e driver to improve performance. On my machine, this yields a throughput increase of 4% for the l2fwd sample app in xdpsock. If we instead just look at the Tx part, this patch set increases throughput with above 20% for Tx. Note that I had to explicitly loop unroll the inner loop to get to this performance level, by using a pragma. It is honored by both clang and gcc and should be ignored by versions that do not support it. Using the -funroll-loops compiler command line switch on the source file resulted in a loop unrolling on a higher level that lead to a performance decrease instead of an increase. Signed-off-by:
John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/1605525167-14450-6-git-send-email-magnus.karlsson@gmail.com
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Magnus Karlsson authored
Introduce batched descriptor interfaces in the xsk core code for the Tx path to be used in the driver to write a code path with higher performance. This interface will be used by the i40e driver in the next patch. Though other drivers would likely benefit from this new interface too. Note that batching is only implemented for the common case when there is only one socket bound to the same device and queue id. When this is not the case, we fall back to the old non-batched version of the function. Signed-off-by:
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Magnus Karlsson authored
Introduce one cache line worth of padding between the consumer pointer and the flags field as well as between the flags field and the start of the descriptors in all the lockless rings. This so that the x86 HW adjacency prefetcher will not prefetch the adjacent pointer/field when only one pointer/field is going to be used. This improves throughput performance for the l2fwd sample app with 1% on my machine with HW prefetching turned on in the BIOS. Signed-off-by:
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Magnus Karlsson authored
Remove the unnecessary access to the software ring for the AF_XDP zero-copy driver. This was used to record the length of the packet so that the driver Tx completion code could sum this up to produce the total bytes sent. This is now performed during the transmission of the packet, so no need to record this in the software ring. Signed-off-by:
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Magnus Karlsson authored
Increment the statistics over how many Tx packets have been sent at the time of sending instead of at the time of completion. This as a completion event means that the buffer has been sent AND returned to user space. The packet always gets sent shortly after sendto() is called. The kernel might, for performance reasons, decide to not return every single buffer to user space immediately after sending, for example, only after a batch of packets have been transmitted. Incrementing the number of packets sent at completion, will in that case be confusing as if you send a single packet, the counter might show zero for a while even though the packet has been transmitted. Signed-off-by:
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Alan Maguire authored
When operating on split BTF, btf__find_by_name[_kind] will not iterate over all types since they use btf->nr_types to show the number of types to iterate over. For split BTF this is the number of types _on top of base BTF_, so it will underestimate the number of types to iterate over, especially for vmlinux + module BTF, where the latter is much smaller. Use btf__get_nr_types() instead. Fixes: ba451366 ("libbpf: Implement basic split BTF support") Signed-off-by:
Alan Maguire <alan.maguire@oracle.com> Signed-off-by:
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Martin KaFai Lau authored
The intention of the current check is to avoid using bpf_sk_storage in irq and nmi. Jakub pointed out that the current check cannot do that. For example, in_serving_softirq() returns true if the softirq handling is interrupted by hard irq. Fixes: 8e4597c6 ("bpf: Allow using bpf_sk_storage in FENTRY/FEXIT/RAW_TP") Suggested-by:
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