Thomas Gleixner c2da3f1b71 proc/stat: Make the interrupt statistics more efficient ... Waiman reported that on large systems with a large amount of interrupts the readout of /proc/stat takes a long time to sum up the interrupt statistics. In principle this is not a problem. but for unknown reasons some enterprise quality software reads /proc/stat with a high frequency. The reason for this is that interrupt statistics are accounted per cpu. So the /proc/stat logic has to sum up the interrupt stats for each interrupt. The interrupt core provides now a per interrupt summary counter which can be used to avoid the summation loops completely except for interrupts marked PER_CPU which are only a small fraction of the interrupt space if at all. Another simplification is to iterate only over the active interrupts and skip the potentially large gaps in the interrupt number space and just print zeros for the gaps without going into the interrupt core in the first place. Waiman provided test results from a 4-socket IvyBridge-EX system (60-core 120-thread, 3016 irqs) excuting a test program which reads /proc/stat 50,000 times: Before: 18.436s (sys 18.380s) After: 3.769s (sys 3.742s) Reported-by: Waiman Long <longman@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Waiman Long <longman@redhat.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: linux-fsdevel@vger.kernel.org Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Daniel Colascione <dancol@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Randy Dunlap <rdunlap@infradead.org> Link: https://lkml.kernel.org/r/20190208135021.013828701@linutronix.de		2019-02-10 21:34:46 +01:00
..
9p	Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2018-11-01 19:58:52 -07:00
adfs	adfs: use timespec64 for time conversion	2018-08-22 10:52:51 -07:00
affs	…
afs	fs: don't open code lru_to_page()	2019-01-04 13:13:48 -08:00
autofs	autofs: add strictexpire mount option	2019-01-04 13:13:47 -08:00
befs	…
bfs	bfs: extra sanity checking and static inode bitmap	2019-01-04 13:13:47 -08:00
btrfs	for-5.0-rc1-tag	2019-01-14 05:55:51 +12:00
cachefiles	fscache, cachefiles: remove redundant variable 'cache'	2018-11-30 16:00:58 +00:00
ceph	ceph: use vmf_error() in ceph_filemap_fault()	2019-01-07 22:48:48 +01:00
cifs	cifs: update internal module version number	2019-01-11 07:14:40 -06:00
coda	…
configfs	…
cramfs	Make the Cramfs code more robust against filesystem corruptions,	2018-10-30 12:46:25 -07:00
crypto	fscrypt: add Adiantum support	2019-01-06 08:36:21 -05:00
debugfs	…
devpts	devpts: Convert to new IDA API	2018-08-21 23:54:17 -04:00
dlm	dlm: fix invalid cluster name warning	2018-12-03 15:30:24 -06:00
ecryptfs	ecryptfs_rename(): verify that lower dentries are still OK after lock_rename()	2018-10-09 23:33:17 -04:00
efivarfs	efivars: Call guid_parse() against guid_t type of variable	2018-07-22 14:13:44 +02:00
efs	…
exofs	exofs_mount(): fix leaks on failure exits	2018-12-17 18:36:33 -05:00
exportfs	exportfs: do not read dentry after free	2018-11-23 09:08:17 -05:00
ext2	\n	2018-12-27 17:00:35 -08:00
ext4	Fix a number of ext4 bugs.	2019-01-06 12:19:23 -08:00
f2fs	f2fs-for-4.21-rc1	2018-12-31 09:41:37 -08:00
fat	Merge branch 'akpm' (patches from Andrew)	2019-01-05 09:16:18 -08:00
freevxfs	…
fscache	fscache: fix race between enablement and dropping of object	2018-11-30 15:57:31 +00:00
fuse	mm: convert totalram_pages and totalhigh_pages variables to atomic	2018-12-28 12:11:47 -08:00
gfs2	File locking changes for v4.21	2018-12-27 17:12:30 -08:00
hfs	hfs: do not free node before using	2018-11-30 14:56:14 -08:00
hfsplus	hfsplus: return file attributes on statx	2019-01-04 13:13:47 -08:00
hostfs	vfs: discard ATTR_ATTR_FLAG	2018-08-17 16:20:28 -07:00
hpfs	hpfs: remove unnecessary checks on the value of r when assigning error code	2018-08-25 12:42:33 -07:00
hugetlbfs	hugetlbfs: revert "Use i_mmap_rwsem to fix page fault/truncate race"	2019-01-08 17:15:11 -08:00
isofs	Update email address	2018-09-29 22:47:48 -04:00
jbd2	jbd2: clean up indentation issue, replace spaces with tab	2018-12-04 00:20:10 -05:00
jffs2	jffs2: Fix use of uninitialized delayed_work, lockdep breakage	2018-12-02 09:20:34 +01:00
jfs	jfs: remove redundant dquot_initialize() in jfs_evict_inode()	2018-09-20 09:28:49 -05:00
kernfs	kernfs: Improve kernfs_notify() poll notification latency	2018-11-27 11:59:33 +01:00
lockd	NFS client updates for Linux 4.21	2019-01-02 16:35:23 -08:00
minix	…
nfs	Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-01-05 13:25:58 -08:00
nfs_common	…
nfsd	NFS client updates for Linux 4.21	2019-01-02 16:35:23 -08:00
nilfs2	nilfs2: Use xa_erase_irq	2018-11-05 14:57:05 -05:00
nls	…
notify	fanotify: Use inode_is_open_for_write	2018-12-11 10:55:45 +01:00
ntfs	mm: convert totalram_pages and totalhigh_pages variables to atomic	2018-12-28 12:11:47 -08:00
ocfs2	Merge branch 'akpm' (patches from Andrew)	2019-01-05 09:16:18 -08:00
omfs	…
openpromfs	fs/openpromfs: Use of_node_name_eq for node name comparisons	2018-11-18 13:35:19 -08:00
orangefs	fs: don't open code lru_to_page()	2019-01-04 13:13:48 -08:00
overlayfs	Revert "ovl: relax permission checking on underlying layers"	2018-12-04 11:31:30 +01:00
proc	proc/stat: Make the interrupt statistics more efficient	2019-02-10 21:34:46 +01:00
pstore	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
qnx4	…
qnx6	…
quota	quota: Lock s_umount in exclusive mode for Q_XQUOTA{ON,OFF} quotactls.	2018-12-18 18:29:15 +01:00
ramfs	…
reiserfs	reiserfs: remove workaround code for GCC 3.x	2018-10-31 08:54:14 -07:00
romfs	…
squashfs	Squashfs: Compute expected length from inode size rather than block length	2018-08-02 09:34:02 -07:00
sysfs	sysfs: convert BUG_ON to WARN_ON	2019-01-07 08:53:32 +01:00
sysv	sysv: return 'err' instead of 0 in __sysv_write_inode	2018-11-10 08:02:40 -05:00
tracefs	tracefs: Annotate tracefs_ops with __ro_after_init	2018-07-31 11:32:44 -04:00
ubifs	mm: migrate: drop unused argument of migrate_page_move_mapping()	2018-12-28 12:11:51 -08:00
udf	\n	2018-12-27 17:00:35 -08:00
ufs	fs/ufs: use ktime_get_real_seconds for sb and cg timestamps	2018-08-17 16:20:27 -07:00
xfs	xfs: xfs_fsops: drop useless LIST_HEAD	2018-12-29 10:47:58 -08:00
Kconfig	…
Kconfig.binfmt	kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt	2018-08-02 08:06:55 +09:00
Makefile	…
aio.c	Merge branch 'akpm' (patches from Andrew)	2018-12-28 16:55:46 -08:00
anon_inodes.c	…
attr.c	…
bad_inode.c	…
binfmt_aout.c	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
binfmt_elf.c	signal: Distinguish between kernel_siginfo and siginfo	2018-10-03 16:47:43 +02:00
binfmt_elf_fdpic.c	…
binfmt_em86.c	…
binfmt_flat.c	…
binfmt_misc.c	…
binfmt_script.c	exec: load_script: don't blindly truncate shebang string	2019-01-04 13:13:47 -08:00
block_dev.c	block: don't use un-ordered __set_current_state(TASK_UNINTERRUPTIBLE)	2019-01-02 10:46:03 -08:00
buffer.c	fs/: remove caller signal_pending branch predictions	2019-01-04 13:13:48 -08:00
char_dev.c	…
compat.c	…
compat_binfmt_elf.c	y2038: globally rename compat_time to old_time32	2018-08-27 14:48:48 +02:00
compat_ioctl.c	media updates for v4.20-rc1	2018-10-29 14:29:58 -07:00
coredump.c	signal: Distinguish between kernel_siginfo and siginfo	2018-10-03 16:47:43 +02:00
d_path.c	…
dax.c	dax fix 4.21	2018-12-31 09:46:39 -08:00
dcache.c	mm: remove include/linux/bootmem.h	2018-10-31 08:54:16 -07:00
dcookies.c	…
direct-io.c	Linux 4.20-rc5	2018-12-04 09:38:05 -07:00
drop_caches.c	…
eventfd.c	…
eventpoll.c	Merge branch 'akpm' (patches from Andrew)	2019-01-05 09:16:18 -08:00
exec.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-01-05 13:18:59 -08:00
fcntl.c	signal: Distinguish between kernel_siginfo and siginfo	2018-10-03 16:47:43 +02:00
fhandle.c	…
file.c	Char/Misc driver patches for 4.21-rc1	2018-12-28 20:54:57 -08:00
file_table.c	mm: convert totalram_pages and totalhigh_pages variables to atomic	2018-12-28 12:11:47 -08:00
filesystems.c	…
fs-writeback.c	fs: Convert writeback to XArray	2018-10-21 10:46:42 -04:00
fs_pin.c	…
fs_struct.c	…
inode.c	y2038: more syscalls and cleanups	2018-12-28 12:45:04 -08:00
internal.h	overlayfs update for 4.19	2018-08-21 18:19:09 -07:00
ioctl.c	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
iomap.c	block: don't use un-ordered __set_current_state(TASK_UNINTERRUPTIBLE)	2019-01-02 10:46:03 -08:00
libfs.c	…
locks.c	locks: fix error in locks_move_blocks()	2019-01-02 20:14:50 -05:00
mbcache.c	…
mount.h	…
mpage.c	mpage: mpage_readpages() should submit IO as read-ahead	2018-08-17 16:20:29 -07:00
namei.c	Revert "vfs: Allow userns root to call mknod on owned filesystems."	2018-12-22 14:18:34 -08:00
namespace.c	Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-01-05 13:25:58 -08:00
no-block.c	…
nsfs.c	…
open.c	overlayfs update for 4.19	2018-08-21 18:19:09 -07:00
pipe.c	Merge branch 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2018-08-13 19:58:36 -07:00
pnode.c	vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled	2018-12-20 16:32:56 +00:00
pnode.h	…
posix_acl.c	…
proc_namespace.c	…
read_write.c	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
readdir.c	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
select.c	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
seq_file.c	fs/seq_file.c: simplify seq_file iteration code and interface	2018-08-17 16:20:28 -07:00
signalfd.c	signal: Distinguish between kernel_siginfo and siginfo	2018-10-03 16:47:43 +02:00
splice.c	splice: don't read more than available pipe space	2018-12-04 08:50:49 -08:00
stack.c	…
stat.c	y2038: Remove newstat family from default syscall set	2018-08-29 15:42:20 +02:00
statfs.c	…
super.c	mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT	2018-12-21 11:51:23 -05:00
sync.c	…
timerfd.c	y2038: globally rename compat_time to old_time32	2018-08-27 14:48:48 +02:00
userfaultfd.c	userfaultfd: clear flag if remap event not enabled	2018-12-28 12:11:51 -08:00
utimes.c	y2038: utimes: Rework #ifdef guards for compat syscalls	2018-08-29 15:42:23 +02:00
xattr.c	sysfs: Do not return POSIX ACL xattrs via listxattr	2018-09-18 07:30:48 -04:00