linux_dsm_epyc7002/include
Lukas Czerner 7b5a35225b loop: Limit the number of requests in the bio list
Currently there is not limitation of number of requests in the loop bio
list. This can lead into some nasty situations when the caller spawns
tons of bio requests taking huge amount of memory. This is even more
obvious with discard where blkdev_issue_discard() will submit all bios
for the range and wait for them to finish afterwards. On really big loop
devices and slow backing file system this can lead to OOM situation as
reported by Dave Chinner.

With this patch we will wait in loop_make_request() if the number of
bios in the loop bio list would exceed 'nr_congestion_on'.
We'll wake up the process as we process the bios form the list. Some
threshold hysteresis is in place to avoid high frequency oscillation.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reported-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-11-30 11:48:05 +01:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-10-08 07:14:06 +09:00
asm-generic UAPI: Remove empty non-UAPI Kbuild files 2012-10-17 12:31:15 +01:00
clocksource
crypto Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
drm drm/radeon: add some new SI PCI ids 2012-10-23 10:23:49 -04:00
keys KEYS: Asymmetric key pluggable data parsers 2012-10-08 13:50:13 +10:30
linux loop: Limit the number of requests in the bio list 2012-11-30 11:48:05 +01:00
math-emu
media Merge branch 'exynos-drm-next' of git://git.infradead.org/users/kmpark/linux-samsung into drm-next 2012-10-07 21:06:33 +10:00
memory
misc
net Merge branch 'for-john' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211 2012-10-17 16:23:33 -04:00
pcmcia
ras
rdma infiniband: pass rdma_cm module to netlink_dump_start 2012-10-07 00:30:56 -04:00
rxrpc
scsi SCSI misc on 20121012 2012-10-13 10:57:01 +09:00
sound Sound updates for 3.7-rc1 2012-10-09 07:07:14 +09:00
target target: Add target_submit_cmd_map_sgls for SGL fabric memory passthrough 2012-10-02 14:16:08 -07:00
trace Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2012-10-10 10:49:20 +09:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-10-26 15:00:48 -07:00
video fbdev updates for 3.7 2012-10-12 10:21:02 +09:00
xen Bug-fixes: 2012-10-24 05:17:27 +03:00
Kbuild UAPI: Remove empty non-UAPI Kbuild files 2012-10-17 12:31:15 +01:00