mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-09-22 09:34:56 +02:00
Pawan Gupta
f1f36bf9bb
commit a23c1c5396 upstream.
bpf_prog_pack_alloc() issues IBPB on all CPUs on every cBPF allocation,
even when reusing chunks from an existing pack where no new memory was
touched since the last IBPB.
Since IBPB on all CPUs is heavy, Dave Hansen suggested to track allocation
since last IBPB, and only issue IBPB at reuse for the chunks that have not
seen an IBPB since they were last freed.
Track per-pack whether an IBPB is needed via arch_flush_needed. Set it when
allocating a chunk, reset on IBPB flush. On reuse, conditionally issue the
flush. Since IBPB invalidates all BTB entries, clear the flag on all packs
after flushing.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 reStructuredText 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.