Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
6510ea973d
The macro dev_core_stats_##FIELD##_inc() disables preemption and invokes netdev_core_stats_alloc() to return a per-CPU pointer. netdev_core_stats_alloc() will allocate memory on its first invocation which breaks on PREEMPT_RT because it requires non-atomic context for memory allocation. This can be avoided by enabling preemption in netdev_core_stats_alloc() assuming the caller always disables preemption. It might be better to replace local_inc() with this_cpu_inc() now that dev_core_stats_##FIELD##_inc() gained a preempt-disable section and does not rely on already disabled preemption. This results in less instructions on x86-64: local_inc: | incl %gs:__preempt_count(%rip) # __preempt_count | movq 488(%rdi), %rax # _1->core_stats, _22 | testq %rax, %rax # _22 | je .L585 #, | add %gs:this_cpu_off(%rip), %rax # this_cpu_off, tcp_ptr__ | .L586: | testq %rax, %rax # _27 | je .L587 #, | incq (%rax) # _6->a.counter | .L587: | decl %gs:__preempt_count(%rip) # __preempt_count this_cpu_inc(), this patch: | movq 488(%rdi), %rax # _1->core_stats, _5 | testq %rax, %rax # _5 | je .L591 #, | .L585: | incq %gs:(%rax) # _18->rx_dropped Use unsigned long as type for the counter. Use this_cpu_inc() to increment the counter. Use a plain read of the counter. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/YmbO0pxgtKpCw4SY@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.