linux/include
Arnd Bergmann ddc212313f blkcg: simplify statistic accumulation code
Some older compilers (gcc-4.4 through 4.6 in particular) struggle
with the way that blkg_rwstat_read() returns a structure, leading
to excessive stack usage and rather inefficient code:

block/blk-cgroup.c: In function 'blkg_destroy':
block/blk-cgroup.c:354:1: error: the frame size of 1296 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
block/cfq-iosched.c: In function 'cfqg_stats_add_aux':
block/cfq-iosched.c:753:1: error: the frame size of 1928 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
block/bfq-cgroup.c: In function 'bfqg_stats_add_aux':
block/bfq-cgroup.c:299:1: error: the frame size of 1928 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

I also notice that there is no point in using atomic accesses
for the local variables, so storing the temporaries in simple 'u64'
variables not only avoids the stack usage on older compilers but
also improves the object code on modern versions.

Fixes: e6269c4454 ("blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it")
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-16 08:56:36 -07:00
..
acpi Merge branch 'acpi-ec' into acpi 2017-11-30 13:37:29 +01:00
asm-generic mm: switch to 'define pmd_write' instead of __HAVE_ARCH_PMD_WRITE 2017-11-29 18:40:42 -08:00
clocksource arm64 updates for 4.15 2017-11-15 10:56:56 -08:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-12-11 16:32:45 -08:00
drm drm: rework delayed connector cleanup in connector_iter 2017-12-13 22:59:00 +01:00
dt-bindings fixes/cleanups for rc1, non-desktop flags for VR 2017-11-23 21:04:56 -10:00
keys
kvm KVM: arm/arm64: Don't enable/disable physical timer access on VHE 2017-11-29 16:46:09 +01:00
linux blkcg: simplify statistic accumulation code 2018-01-16 08:56:36 -07:00
math-emu
media media updates for v4.15-rc1 2017-11-15 20:30:12 -08:00
memory
misc
net net: sched: Add TCA_HW_OFFLOAD 2017-12-15 13:35:36 -05:00
pcmcia
ras
rdma Updates for 4.15 kernel merge window 2017-11-15 14:54:53 -08:00
scsi scsi: libsas: align sata_device's rps_resp on a cacheline 2017-11-21 23:06:32 -05:00
soc We have two changes to the core framework this time around. The first being a 2017-11-17 20:04:24 -08:00
sound ALSA: hda - Fix yet remaining issue with vmaster 0dB initialization 2017-11-22 12:34:56 +01:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2017-11-24 19:19:20 -10:00
trace Various fix ups. 2017-12-14 18:21:33 -08:00
uapi lightnvm: set target over-provision on create ioctl 2018-01-05 08:50:12 -07:00
video fbdev changes for v4.15: 2017-11-20 21:50:24 -10:00
xen xen: features and fixes for v4.15-rc1 2017-11-16 13:06:27 -08:00