kernel_optimize_test/fs
Paolo 'Blaisorblade' Giarrusso 1e40cd383c [PATCH] uml: fixes performance regression in activate_mm and thus exec()
Normally, activate_mm() is called from exec(), and thus it used to be a
no-op because we use a completely new "MM context" on the host (for
instance, a new process), and so we didn't need to flush any "TLB entries"
(which for us are the set of memory mappings for the host process from the
virtual "RAM" file).

Kernel threads, instead, are usually handled in a different way.  So, when
for AIO we call use_mm(), things used to break and so Benjamin implemented
activate_mm().  However, that is only needed for AIO, and could slow down
exec() inside UML, so be smart: detect being called for AIO (via
PF_BORROWED_MM) and do the full flush only in that situation.

Comment also the caller so that people won't go breaking UML without
noticing.  I also rely on the caller's locks for testing current->flags.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
CC: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:21 -07:00
..
adfs
affs
afs
autofs
autofs4
befs
bfs
cifs
coda
cramfs
debugfs
devfs
devpts
efs
exportfs
ext2
ext3
fat
freevxfs
hfs
hfsplus
hostfs
hpfs
hppfs
hugetlbfs
isofs
jbd
jffs
jffs2
jfs
lockd
minix
msdos
ncpfs
nfs
nfs_common
nfsd
nls
ntfs
openpromfs
partitions
proc
qnx4
ramfs
reiserfs
romfs
smbfs
sysfs
sysv
udf
ufs
umsdos
vfat
xfs
aio.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio.c
block_dev.c
buffer.c
char_dev.c
compat_ioctl.c
compat.c
dcache.c
dcookies.c
direct-io.c
dnotify.c
dquot.c
eventpoll.c
exec.c
fcntl.c
fifo.c
file_table.c
file.c
filesystems.c
fs-writeback.c
inode.c
inotify.c
ioctl.c
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mpage.c
namei.c
namespace.c
nfsctl.c
open.c
pipe.c
posix_acl.c
quota_v1.c
quota_v2.c
quota.c
read_write.c
readdir.c
select.c
seq_file.c
stat.c
super.c
xattr_acl.c
xattr.c