5b82798f78
[ Upstream commit 7b723008f9c95624c848fad661c01b06e47b20da ] While converting the NFSv4 decoder to use xdr_stream-based XDR processing, I removed the old SAVEMEM() macro. This macro wrapped a bit of logic that avoided a memory allocation by recognizing when the decoded item resides in a linear section of the Receive buffer. In that case, it returned a pointer into that buffer instead of allocating a bounce buffer. The bounce buffer is necessary only when xdr_inline_decode() has placed the decoded item in the xdr_stream's scratch buffer, which disappears the next time xdr_inline_decode() is called with that xdr_stream. That happens only if the data item crosses a page boundary in the receive buffer, an exceedingly rare occurrence. Allocating a bounce buffer every time results in a minor performance regression that was introduced by the recent NFSv4 decoder overhaul. Let's restore the previous behavior. On average, it saves about 1.5 kmalloc() calls per COMPOUND. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> 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 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.