e81faa91a5
From: Yu Kuai <yukuai3@huawei.com> Co-developed-by: Paul Luse <paul.e.luse@linux.intel.com> The original idea is that Paul want to optimize raid1 read performance([1]), however, we think that the original code for read_balance() is quite complex, and we don't want to add more complexity. Hence we decide to refactor read_balance() first, to make code cleaner and easier for follow up. Before this patchset, read_balance() has many local variables and many branches, it want to consider all the scenarios in one iteration. The idea of this patch is to divide them into 4 different steps: 1) If resync is in progress, find the first usable disk, patch 5; Otherwise: 2) Loop through all disks and skipping slow disks and disks with bad blocks, choose the best disk, patch 10. If no disk is found: 3) Look for disks with bad blocks and choose the one with most number of sectors, patch 8. If no disk is found: 4) Choose first found slow disk with no bad blocks, or slow disk with most number of sectors, patch 7. Note that step 3) and step 4) are super code path, and performance should not be considered. And after this patchset, we'll continue to optimize read_balance for step 2), specifically how to choose the best rdev to read. [1] https://lore.kernel.org/all/20240102125115.129261-1-paul.e.luse@linux.intel.com/ Yu Kuai (11): md: add a new helper rdev_has_badblock() md/raid1: factor out helpers to add rdev to conf md/raid1: record nonrot rdevs while adding/removing rdevs to conf md/raid1: fix choose next idle in read_balance() md/raid1-10: add a helper raid1_check_read_range() md/raid1-10: factor out a new helper raid1_should_read_first() md/raid1: factor out read_first_rdev() from read_balance() md/raid1: factor out choose_slow_rdev() from read_balance() md/raid1: factor out choose_bb_rdev() from read_balance() md/raid1: factor out the code to manage sequential IO md/raid1: factor out helpers to choose the best rdev from read_balance() |
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| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
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| 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.