mainlining shenanigans
a1d198478e
Although btrfs heavily relies on extent_io_tree, we don't really have any good trace events for them. This patch will add the folowing trace events: - trace_btrfs_set_extent_bit() - trace_btrfs_clear_extent_bit() - trace_btrfs_convert_extent_bit() Since selftests could create temporary extent_io_tree without fs_info, modify TP_fast_assign_fsid() to accept NULL as fs_info. NULL fs_info will lead to all zero fsid. The output would be: btrfs_set_extent_bit: <FDID>: io_tree=INODE_IO ino=1 root=1 start=22036480 len=4096 set_bits=LOCKED btrfs_set_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22040576 len=4096 set_bits=LOCKED btrfs_set_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22044672 len=4096 set_bits=LOCKED btrfs_set_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22048768 len=4096 set_bits=LOCKED btrfs_clear_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22036480 len=16384 clear_bits=LOCKED ^^^ Extent buffer 22036480 read from disk, the locking progress btrfs_set_extent_bit: <FSID>: io_tree=TRANS_DIRTY_PAGES ino=1 root=1 start=30425088 len=16384 set_bits=DIRTY btrfs_set_extent_bit: <FSID>: io_tree=TRANS_DIRTY_PAGES ino=1 root=1 start=30441472 len=16384 set_bits=DIRTY ^^^ 2 new tree blocks allocated in one transaction btrfs_set_extent_bit: <FSID>: io_tree=FREED_EXTENTS0 ino=0 root=0 start=30523392 len=16384 set_bits=DIRTY btrfs_set_extent_bit: <FSID>: io_tree=FREED_EXTENTS0 ino=0 root=0 start=30556160 len=16384 set_bits=DIRTY ^^^ 2 old tree blocks get pinned down There is one point which need attention: 1) Those trace events can be pretty heavy: The following workload would generate over 400 trace events. mkfs.btrfs -f $dev start_trace mount $dev $mnt -o enospc_debug sync touch $mnt/file1 touch $mnt/file2 touch $mnt/file3 xfs_io -f -c "pwrite 0 16k" $mnt/file4 umount $mnt end_trace It's not recommended to use them in real world environment. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ rename enums ] Signed-off-by: David Sterba <dsterba@suse.com> |
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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.