kernel_optimize_test/include
Waiman Long af0c9af1b3 fs/dcache: Track & report number of negative dentries
The current dentry number tracking code doesn't distinguish between
positive & negative dentries.  It just reports the total number of
dentries in the LRU lists.

As excessive number of negative dentries can have an impact on system
performance, it will be wise to track the number of positive and
negative dentries separately.

This patch adds tracking for the total number of negative dentries in
the system LRU lists and reports it in the 5th field in the
/proc/sys/fs/dentry-state file.  The number, however, does not include
negative dentries that are in flight but not in the LRU yet as well as
those in the shrinker lists which are on the way out anyway.

The number of positive dentries in the LRU lists can be roughly found by
subtracting the number of negative dentries from the unused count.

Matthew Wilcox had confirmed that since the introduction of the
dentry_stat structure in 2.1.60, the dummy array was there, probably for
future extension.  They were not replacements of pre-existing fields.
So no sane applications that read the value of /proc/sys/fs/dentry-state
will do dummy thing if the last 2 fields of the sysctl parameter are not
zero.  IOW, it will be safe to use one of the dummy array entry for
negative dentry count.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-30 11:02:11 -08:00
..
acpi
asm-generic
clocksource
crypto
drm Merge tag 'drm-intel-fixes-2019-01-11' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes 2019-01-11 10:26:21 +01:00
dt-bindings dt-bindings: reset: meson-axg: fix SPDX license id 2019-01-16 12:50:27 -06:00
keys
kvm
linux fs/dcache: Track & report number of negative dentries 2019-01-30 11:02:11 -08:00
math-emu
media
memory
misc
net net: tls: Save iv in tls_rec for async crypto requests 2019-01-28 23:05:55 -08:00
pcmcia
ras
rdma
scsi
soc
sound ASoC: Fixes for v5.0 2019-01-18 15:17:17 +01:00
target
trace afs: Fix race in async call refcounting 2019-01-17 15:17:28 +00:00
uapi Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2019-01-27 09:07:03 -08:00
video
xen arm64/xen: fix xen-swiotlb cache flushing 2019-01-23 22:14:56 +01:00