The patch titled
revert "kswapd should only wait on IO if there is IO"
has been added to the -mm tree. Its filename is
revert-kswapd-should-only-wait-on-io-if-there-is-io.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: revert "kswapd should only wait on IO if there is IO"
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Revert
commit f1a9ee758de7de1e040de849fdef46e6802ea117
Author: Rik van Riel <riel@xxxxxxxxxx>
Date: Thu Feb 7 00:14:08 2008 -0800
kswapd should only wait on IO if there is IO
The current kswapd (and try_to_free_pages) code has an oddity where the
code will wait on IO, even if there is no IO in flight. This problem is
notable especially when the system scans through many unfreeable pages,
causing unnecessary stalls in the VM.
Additionally, tasks without __GFP_FS or __GFP_IO in the direct reclaim path
will sleep if a significant number of pages are encountered that should be
written out. This gives kswapd a chance to write out those pages, while
the direct reclaim task sleeps.
Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Because of large latencies and interactivity problems reported by Carlos,
here: http://lkml.org/lkml/2008/3/22/211
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: "Carlos R. Mafra" <crmafra2@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 27 +++++----------------------
1 file changed, 5 insertions(+), 22 deletions(-)
diff -puN mm/vmscan.c~revert-kswapd-should-only-wait-on-io-if-there-is-io mm/vmscan.c
--- a/mm/vmscan.c~revert-kswapd-should-only-wait-on-io-if-there-is-io
+++ a/mm/vmscan.c
@@ -70,13 +70,6 @@ struct scan_control {
int order;
- /*
- * Pages that have (or should have) IO pending. If we run into
- * a lot of these, we're better off waiting a little for IO to
- * finish rather than scanning more pages in the VM.
- */
- int nr_io_pages;
-
/* Which cgroup do we reclaim from */
struct mem_cgroup *mem_cgroup;
@@ -512,10 +505,8 @@ static unsigned long shrink_page_list(st
*/
if (sync_writeback == PAGEOUT_IO_SYNC && may_enter_fs)
wait_on_page_writeback(page);
- else {
- sc->nr_io_pages++;
+ else
goto keep_locked;
- }
}
referenced = page_referenced(page, 1, sc->mem_cgroup);
@@ -554,10 +545,8 @@ static unsigned long shrink_page_list(st
if (PageDirty(page)) {
if (sc->order <= PAGE_ALLOC_COSTLY_ORDER && referenced)
goto keep_locked;
- if (!may_enter_fs) {
- sc->nr_io_pages++;
+ if (!may_enter_fs)
goto keep_locked;
- }
if (!sc->may_writepage)
goto keep_locked;
@@ -568,10 +557,8 @@ static unsigned long shrink_page_list(st
case PAGE_ACTIVATE:
goto activate_locked;
case PAGE_SUCCESS:
- if (PageWriteback(page) || PageDirty(page)) {
- sc->nr_io_pages++;
+ if (PageWriteback(page) || PageDirty(page))
goto keep;
- }
/*
* A synchronous write - probably a ramdisk. Go
* ahead and try to reclaim the page.
@@ -1344,7 +1331,6 @@ static unsigned long do_try_to_free_page
for (priority = DEF_PRIORITY; priority >= 0; priority--) {
sc->nr_scanned = 0;
- sc->nr_io_pages = 0;
if (!priority)
disable_swap_token();
nr_reclaimed += shrink_zones(priority, zones, sc);
@@ -1379,8 +1365,7 @@ static unsigned long do_try_to_free_page
}
/* Take a nap, wait for some writeback to complete */
- if (sc->nr_scanned && priority < DEF_PRIORITY - 2 &&
- sc->nr_io_pages > sc->swap_cluster_max)
+ if (sc->nr_scanned && priority < DEF_PRIORITY - 2)
congestion_wait(WRITE, HZ/10);
}
/* top priority shrink_caches still had more to do? don't OOM, then */
@@ -1514,7 +1499,6 @@ loop_again:
if (!priority)
disable_swap_token();
- sc.nr_io_pages = 0;
all_zones_ok = 1;
/*
@@ -1607,8 +1591,7 @@ loop_again:
* OK, kswapd is getting into trouble. Take a nap, then take
* another pass across the zones.
*/
- if (total_scanned && priority < DEF_PRIORITY - 2 &&
- sc.nr_io_pages > sc.swap_cluster_max)
+ if (total_scanned && priority < DEF_PRIORITY - 2)
congestion_wait(WRITE, HZ/10);
/*
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
origin.patch
mtd-memory-corruption-in-block2mtdc.patch
revert-kswapd-should-only-wait-on-io-if-there-is-io.patch
lib-swiotlbc-avoid-endless-loops-fix.patch
git-x86.patch
i386-arch-x86-math-emu-fpu_entryc-warning-fix.patch
git-kgdb-light.patch
git-acpi-fixup.patch
git-acpi-arch-x86-kernel-apm_32c-fix-warning.patch
acpi-enable-c3-power-state-on-dell-inspiron-8200.patch
git-alsa-tiwai.patch
cifs-suppress-warning.patch
git-drm.patch
git-drm-git-rejects.patch
git-drm-drivers-char-drm-ati_pcigartc-fix-printk-warning.patch
git-dvb.patch
drivers-media-video-pvrusb2-pvrusb2-sysfsc-fix-printk-warnings.patch
git-hwmon.patch
git-gfs2-nmw.patch
git-hrt.patch
arch-ia64-kernel-use-time_-macros-checkpatch-fixes.patch
git-ieee1394.patch
git-infiniband.patch
git-infiniband-vs-gregkh-driver-ib-convert-struct-class_device-to-struct-device.patch
maple-add-driver-for-sega-dreamcast-controller.patch
git-kvm.patch
git-leds.patch
devres-implement-pcim_iomap_regions_request_all-fix.patch
devres-implement-pcim_iomap_regions_request_all-fix-fix.patch
git-async-tx.patch
drivers-atm-firestreamc-suppress-uninitialized-var-warning.patch
wan-new-ppp-code-for-generic-hdlc-checkpatch-fixes.patch
drivers-net-bonding-bond_sysfsc-suppress-uninitialized-var-warning.patch
drivers-net-arcnet-arcnetc-use-time_-macros-checkpatch-fixes.patch
drivers-net-tokenring-3c359c-use-time_-macros-checkpatch-fixes.patch
update-smc91x-driver-with-arm-versatile-board-info.patch
fs-nfs-callback_xdrc-suppress-uninitialiized-variable-warnings.patch
git-nfsd.patch
git-ocfs2.patch
arch-parisc-kernel-unalignedc-use-time_-macros-checkpatch-fixes.patch
drivers-pcmcia-soc_commonc-convert-soc_pcmcia_sockets_lock-into-a-mutex-and-make-it-static.patch
git-selinux.patch
git-sh.patch
git-sh-git-rejects.patch
git-scsi-misc-vs-gregkh-driver-driver-core-remove-no-longer-used-struct-class_device.patch
git-scsi-misc-vs-gregkh-driver-driver-core-remove-no-longer-used-struct-class_device-fix.patch
scsi-aic94xx-cleanups.patch
scsi-fix-section-mismatch-in-aic94xx-fix.patch
scsi-chc-fix-shadowed-variable-warnings-checkpatch-fixes.patch
ipsc-fix-build-warning.patch
drivers-scsi-initioc-suppress-compile-warning.patch
drivers-scsi-hptiopc-fix-build-warning.patch
drivers-scsi-mvsasc-fix-build-warnings.patch
scsi-add-iscsi-ibft-support-fix.patch
git-block-git-rejects.patch
git-unionfs.patch
fix-gregkh-usb-usb-ohci-port-reset-paranoia-timeout.patch
git-v9fs.patch
git-watchdog.patch
xfs-suppress-uninitialized-var-warnings.patch
git-xtensa.patch
git-semaphore-git-rejects.patch
remove-sparse-warning-for-mmzoneh-checkpatch-fixes.patch
fix-invalidate_inode_pages2_range-to-not-clear-ret-checkpatch-fixes.patch
mm-make-mem_map-allocation-continuous-checkpatch-fixes.patch
mm-make-early_pfn_to_nid-a-c-function.patch
vmalloc-show-vmalloced-areas-via-proc-vmallocinfo-checkpatch-fixes.patch
vmallocinfo-add-caller-information-checkpatch-fixes.patch
vmscan-give-referenced-active-and-unmapped-pages-a-second-trip-around-the-lru.patch
vm-dont-run-touch_buffer-during-buffercache-lookups.patch
capabilities-implement-per-process-securebits-warning-fix.patch
lsm-introduce-inode_getsecid-and-ipc_getsecid-hooks-checkpatch-fixes.patch
lsm-audit-introduce-generic-audit-lsm-hooks-checkpatch-fixes.patch
selinux-use-new-audit-hooks-remove-redundant-exports-checkpatch-fixes.patch
audit-final-renamings-and-cleanup-checkpatch-fixes.patch
arch-alpha-kernel-trapsc-use-time_-macros-fix.patch
alpha-teach-the-compiler-that-bug-doesnt-return.patch
make-dev-kmem-a-config-option-fix.patch
misc-phantom-add-compat-ioctl-checkpatch-fixes.patch
sysrq-add-show-backtrace-on-all-cpus-function-checkpatch-fixes.patch
sysrq-add-show-backtrace-on-all-cpus-function-checkpatch-fixes-cleanup.patch
codafs-fix-build-warning.patch
lib-swiotlbc-cleanups.patch
r-o-bind-mounts-elevate-write-count-for-callers-of-vfs_mkdir-fix.patch
r-o-bind-mounts-elevate-write-count-for-xattr_permission-callers-fix.patch
r-o-bind-mounts-get-write-access-for-vfs_rename-callers-fix.patch
r-o-bind-mounts-check-mnt-instead-of-superblock-directly-fix.patch
r-o-bind-mounts-check-mnt-instead-of-superblock-directly-fix-2.patch
r-o-bind-mounts-get-callers-of-vfs_mknod-create-fix.patch
fs-inodec-use-hlist_for_each_entry-checkpatch-fixes.patch
add-rcu_assign_index-if-ever-needed-fix.patch
add-warn_on_secs-macro-simplification-fix.patch
uart_get_baud_rate-stop-mangling-termios-fix.patch
oprofile-change-cpu_buffer-from-array-to-per_cpu-variable-checkpatch-fixes.patch
vt-notifier-extension-for-accessibility-checkpatch-fixes.patch
kprobes-prevent-probing-of-preempt_schedule-fix.patch
kprobes-prevent-probing-of-preempt_schedule-checkpatch-fixes.patch
quota-various-style-cleanups-checkpatch-fixes.patch
quota-quota-core-changes-for-quotaon-on-remount-quota-ext3-make-ext3-handle-quotaon-on-remount-checkpatch-fixes.patch
quota-quota-core-changes-for-quotaon-on-remount-quota-ext4-make-ext4-handle-quotaon-on-remount-checkpatch-fixes.patch
rtc-isl1208-new-style-conversion-and-minor-bug-fixes-checkpatch-fixes.patch
rtc-pcf8563-new-style-conversion-checkpatch-fixes.patch
rtc-pcf8563-new-style-conversion-checkpatch-fixes-fix.patch
rtc-x1205-new-style-conversion-checkpatch-fixes.patch
gpiochip_reserve-fix.patch
fb-add-support-for-foreign-endianness-force-it-on.patch
fbcon-replace-mono_col-macro-with-static-inline-fix.patch
pm-gxfb-add-hook-to-pm-console-layer-that-allows-disabling-of-suspend-vt-switch-fix.patch
fbdev-driver-for-freescale-8610-and-5121-diu-fix.patch
pnp-use-dev_printk-for-quirk-messages-fix.patch
fat_valid_media-remove-pointless-test.patch
cgroup-api-files-update-cpusets-to-use-cgroup-structured-file-api-fix.patch
add-a-document-describing-the-resource-counter-abstraction-v2-fix.patch
memcgroup-implement-failcounter-reset-checkpatch-fixes.patch
workqueues-shrink-cpu_populated_map-when-cpu-dies-fix.patch
ext4-is-broken.patch
ipc-use-ipc_buildid-directly-from-ipc_addid-cleanup.patch
ipmi-run-to-completion-fixes-checkpatch-fixes.patch
ipmi-style-fixes-in-the-system-interface-code-checkpatch-fixes.patch
sxc-fix-printk-warnings-on-sparc32.patch
elf-fix-shadowed-variables-in-fs-binfmt_elfc.patch
sgi-altix-mmtimer-allow-larger-number-of-timers-per-node-fix.patch
sgi-altix-mmtimer-allow-larger-number-of-timers-per-node-fix-2.patch
epcac-static-functions-and-integer-as-null-pointer-fixes-checkpatch-fixes.patch
keys-add-keyctl-function-to-get-a-security-label-fix.patch
procfs-task-exe-symlink-fix.patch
edd-add-default-mode-config_edd_off=n-override-with-edd=onoff-fix.patch
make-module_sect_attrs-private-to-kernel-modulec-checkpatch-fixes.patch
mm-bdi-export-bdi-attributes-in-sysfs-ia64-fix.patch
basic-braille-screen-reader-support-ppc-fix.patch
hfs-fix-warning-with-64k-page_size.patch
hfsplus-fix-warning-with-64k-page_size.patch
alloc_uid-cleanup.patch
add-macros-similar-to-min-max-min_t-max_t.patch
clocksource-introduce-clock_monotonic_raw-fix-checkpatch-fixes.patch
idr-create-idr_layer_cache-at-boot-time-fix.patch
idr-create-idr_layer_cache-at-boot-time-fix-fix.patch
edac-add-e752x-parameter-for-sysbus_parity-selection-checkpatch-fixes.patch
dma-mapping-ib-expand-ib_umem_get-prototype-fix.patch
reiser4.patch
jens-broke-reiser4patch-added-to-mm-tree.patch
page-owner-tracking-leak-detector.patch
nr_blockdev_pages-in_interrupt-warning.patch
slab-leaks3-default-y.patch
profile-likely-unlikely-macros.patch
profile-likely-unlikely-macros-fix.patch
put_bh-debug.patch
shrink_slab-handle-bad-shrinkers.patch
getblk-handle-2tb-devices.patch
getblk-handle-2tb-devices-fix.patch
undeprecate-pci_find_device.patch
i386-arch-x86-math-emu-reg_ld_strc-fix-warning.patch
w1-build-fix.patch
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