mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2025-01-24 14:54:49 +08:00
964a9b0f61
The ring is a precious resource: we anticipate to only use a few hundred bytes for a request, and only try to reserve that before we start. If we go beyond our guess in building the request, then instead of waiting at the start of execbuf before we hold any locks or other resources, we may trigger a wait inside a critical region. One example is in using gpu relocations, where currently we emit a new MI_BB_START from the ring every time we overflow a page of relocation entries. However, instead of insert the command into the precious ring, we can chain the next page of relocation entries as MI_BB_START from the end of the previous. v2: Delay the emit_bb_start until after all the chained vma synchronisation is complete. Since the buffer pool batches are idle, this _should_ be a no-op, but one day we may some fancy async GPU bindings for new vma! v3: Use pool/batch consitently, once we start thinking in terms of the batch vma, use batch->obj. v4: Explain the magic number 4. Tvrtko spotted that we lose propagation of the error for failing to submit the relocation request; that's easier to fix up in the next patch. Testcase: igt/gem_exec_reloc/basic-many-active Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200501192945.22215-1-chris@chris-wilson.co.uk |
||
|---|---|---|
| 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.