systemd

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Alan Jenkins f503f6b22f udevd: implement a more efficient queue file format

Directory lookups show up in profiling. The queue files are responsible
for a large proportion of file-related system calls in udev coldplug.

Instead of creating a file for each event, append their details to a
log file.  The file is periodically rebuilt (garbage-collected) to
prevent it from growing indefinitely.

This single queue file replaces both the queue directory and the
uevent_seqnum file. On desktop systems the file tends not to grow
beyond one page. So it should also save a small amount of memory in
tmpfs.

Tests on a running EeePC indicate average savings of 5% *udevd* cpu time
as measured by oprofile. __link_path_walk is reduced from 1.5% to
1.3%. It is not completely clear where the rest of the gains come from.

In tests running ~400 events, the queue file is rebuilt about 5 times.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>

2009-05-21 22:22:37 +02:00

.gitignore

libudev: add library to access udev information

2008-08-27 17:11:58 +02:00

exported_symbols

udevd: implement a more efficient queue file format

2009-05-21 22:22:37 +02:00

libudev-ctrl.c

use more efficient string copying

2009-05-20 17:57:52 +02:00

libudev-device-db-write.c

fix location of database files