The patch titled
io-accounting: remove current io accounting
has been removed from the -mm tree. Its filename was
io-accounting-remove-current-io-accounting.patch
This patch was dropped because it is obsolete
------------------------------------------------------
Subject: io-accounting: remove current io accounting
From: Andrew Morton <akpm@xxxxxxxx>
The present per-task IO accounting is unusable. It simply counts the number
of bytes passed into read() and write(). So if a process reads 1MB from an
already-cached file, it is accused of having performed 1MB of I/O, which is
hopelessly wrong.
This patchset removes the old IO accounting and replaces it with new
accounting which tries to be more accurate. We account for three things:
reads:
attempt to count the number of bytes which this process really did cause
to be fetched from the storage layer
writes:
attempt to count the number of bytes which this process caused to be sent
to the storage layer.
The big inaccuracy here is truncate. If a process writes 1MB to a file
and then deletes the file, it will in fact perform no writeout. But it will
have been accounted as having caused 1MB of write.
So...
cancelled_writes:
account the number of bytes which this process caused to not happen, by
truncating pagecache.
We _could_ just subtract this from the process's `write' accounting. But
that means that some processes would be reported to have done negative
amounts of write IO, which is silly.
So we just report the raw number and punt this decision up to userspace.
There are some open questions:
- What the heck's going on with userspace? The example getdelays.c appears
to exercise no more than a fraction of the taskstats interface. How do I
get at my numbers?
- Missing accounting of filesystem metadata reads
- Filesystems which implement private a_ops.readpages might need work.
- What to do about things like NFS? It will probably presently account
_some_ IO, but it'll be wrong.
This patch:
Remove the old IO accounting, but leave the fields in the taskstats structure
in-place, but zeroed.
Cc: Jay Lan <jlan@xxxxxxx>
Cc: Shailabh Nagar <nagar@xxxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Cc: Chris Sturtivant <csturtiv@xxxxxxx>
Cc: Tony Ernst <tee@xxxxxxx>
Cc: Guillaume Thouvenin <guillaume.thouvenin@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/read_write.c | 18 ++----------------
include/linux/sched.h | 4 ++--
kernel/fork.c | 2 --
kernel/tsacct.c | 4 ++--
4 files changed, 6 insertions(+), 22 deletions(-)
diff -puN fs/read_write.c~io-accounting-remove-current-io-accounting fs/read_write.c
--- a/fs/read_write.c~io-accounting-remove-current-io-accounting
+++ a/fs/read_write.c
@@ -272,10 +272,8 @@ ssize_t vfs_read(struct file *file, char
ret = file->f_op->read(file, buf, count, pos);
else
ret = do_sync_read(file, buf, count, pos);
- if (ret > 0) {
+ if (ret > 0)
fsnotify_access(file->f_dentry);
- current->rchar += ret;
- }
current->syscr++;
}
}
@@ -330,10 +328,8 @@ ssize_t vfs_write(struct file *file, con
ret = file->f_op->write(file, buf, count, pos);
else
ret = do_sync_write(file, buf, count, pos);
- if (ret > 0) {
+ if (ret > 0)
fsnotify_modify(file->f_dentry);
- current->wchar += ret;
- }
current->syscw++;
}
}
@@ -675,9 +671,6 @@ sys_readv(unsigned long fd, const struct
file_pos_write(file, pos);
fput_light(file, fput_needed);
}
-
- if (ret > 0)
- current->rchar += ret;
current->syscr++;
return ret;
}
@@ -696,9 +689,6 @@ sys_writev(unsigned long fd, const struc
file_pos_write(file, pos);
fput_light(file, fput_needed);
}
-
- if (ret > 0)
- current->wchar += ret;
current->syscw++;
return ret;
}
@@ -780,10 +770,6 @@ static ssize_t do_sendfile(int out_fd, i
retval = in_file->f_op->sendfile(in_file, ppos, count, file_send_actor, out_file);
- if (retval > 0) {
- current->rchar += retval;
- current->wchar += retval;
- }
current->syscr++;
current->syscw++;
diff -puN include/linux/sched.h~io-accounting-remove-current-io-accounting include/linux/sched.h
--- a/include/linux/sched.h~io-accounting-remove-current-io-accounting
+++ a/include/linux/sched.h
@@ -1002,8 +1002,8 @@ struct task_struct {
* to a stack based synchronous wait) if its doing sync IO.
*/
wait_queue_t *io_wait;
-/* i/o counters(bytes read/written, #syscalls */
- u64 rchar, wchar, syscr, syscw;
+ u64 syscr; /* number of read syscalls */
+ u64 syscw; /* number of write syscalls */
#if defined(CONFIG_TASK_XACCT)
u64 acct_rss_mem1; /* accumulated rss usage */
u64 acct_vm_mem1; /* accumulated virtual memory usage */
diff -puN kernel/fork.c~io-accounting-remove-current-io-accounting kernel/fork.c
--- a/kernel/fork.c~io-accounting-remove-current-io-accounting
+++ a/kernel/fork.c
@@ -1051,8 +1051,6 @@ static struct task_struct *copy_process(
p->utime = cputime_zero;
p->stime = cputime_zero;
p->sched_time = 0;
- p->rchar = 0; /* I/O counter: bytes read */
- p->wchar = 0; /* I/O counter: bytes written */
p->syscr = 0; /* I/O counter: read syscalls */
p->syscw = 0; /* I/O counter: write syscalls */
acct_clear_integrals(p);
diff -puN kernel/tsacct.c~io-accounting-remove-current-io-accounting kernel/tsacct.c
--- a/kernel/tsacct.c~io-accounting-remove-current-io-accounting
+++ a/kernel/tsacct.c
@@ -92,8 +92,8 @@ void xacct_add_tsk(struct taskstats *sta
stats->hiwater_vm = mm->hiwater_vm * PAGE_SIZE / KB;
mmput(mm);
}
- stats->read_char = p->rchar;
- stats->write_char = p->wchar;
+ stats->read_char = 0;
+ stats->write_char = 0;
stats->read_syscalls = p->syscr;
stats->write_syscalls = p->syscw;
}
_
Patches currently in -mm which might be from akpm@xxxxxxxx are
origin.patch
tty-signal-tty-locking.patch
pktcdvd-bio-write-congestion-using-blk_congestion_wait.patch
fsstack-introduce-fsstack_copy_attrinode_.patch
log2-implement-a-general-integer-log2-facility-in-the-kernel.patch
add-process_session-helper-routine-deprecate-old-field.patch
mxser-session-warning-fix.patch
mxser-workqueue-fixes.patch
tty-switch-to-ktermios-and-new-framework.patch
tty-switch-to-ktermios.patch
tty_ioctl-use-termios-for-the-old-structure-and-termios2.patch
drivers-isdn-handcrafted-min-max-macro-removal.patch
fault-injection-capabilities-infrastructure.patch
fault-injection-Kconfig-cleanup.patch
fault-injection-stacktrace-filtering-kconfig-fix.patch
sysctl-fix-sys_sysctl-interface-of-ipc-sysctls.patch
video-get-the-default-mode-from-the-right-database.patch
various-fbdev-files-mark-structs.patch
backlight-lcd-remove-dependenct-from-the-framebuffer-layer.patch
gxfb-fixups-for-the-amd-geode-gx.patch
gxfb-support-flat-panel-timings.patch
gxfb-support-command-line-options.patch
proc_misc-build-fix.patch
revert-generic_file_buffered_write-handle-zero-length-iovec-segments.patch
revert-generic_file_buffered_write-deadlock-on-vectored-write.patch
generic_file_buffered_write-cleanup.patch
mm-fix-pagecache-write-deadlocks.patch
fs-prepare_write-fixes-fuse-fix.patch
fs-prepare_write-fixes-fat-fix.patch
macintosh-mangle-caps-lock-events-on-adb-keyboards.patch
git-acpi.patch
git-acpi-fixup.patch
acpi-dont-select-pm.patch
implementation-of-acpi_video_get_next_level.patch
video-sysfs-support-take-2-add-dev-argument-for-backlight_device_register.patch
sony_apci-resume.patch
video-sysfs-support-take-2-add-dev-argument-for-backlight_device_register-sony_acpi-fix.patch
git-alsa.patch
git-alsa-fixup.patch
alsa-workqueue-fixes.patch
git-cpufreq-prep.patch
git-cpufreq.patch
git-cpufreq-fixup.patch
platform_driver_probe-can-save-codespace-save-codespace.patch
git-drm.patch
git-dvb.patch
git-dvb-fixup.patch
git-input-vs-git-alsa.patch
kbuild-fix-rr-is-now-default.patch
pata_cs5530-suspend-resume-support-tweak.patch
pata_sil680-suspend-resume-tidy.patch
pata_via-suspend-resume-support-fix.patch
pata_it8213-add-new-driver-for-the-it8213-card.patch
git-lxdialog-fixup.patch
git-mmc-fixup.patch
git-mmc-tifm_sd-warning-fix.patch
git-mtd.patch
git-mtd-ssfdc-build-fix.patch
git-ubi.patch
ubi-versus-add-include-linux-freezerh-and-move-definitions-from.patch
update-smc91x-driver-with-arm-versatile-board-info.patch
drivers-net-ns83820c-add-paramter-to-disable-auto.patch
net-use-bitrev8.patch
net-uninline-skb_put.patch
ioat-warning-fix.patch
pci-fix-multiple-problems-with-via-hardware.patch
pci-legacy-resource-fix-tidy.patch
git-s390.patch
s390-workqueue-fixes.patch
drivers-scsi-mca_53c9xc-save_flags-cli-removal.patch
scsi-in2000-scsi_cmnd-convertion.patch
aic79xx-wrong-max-memory-at-driver-init.patch
scsi-cover-up-bugs-fix-up-compiler-warnings-in-megaraid-driver-fix.patch
git-qla3xxx-fixup.patch
nokia-e70-is-an-unusual-device.patch
revert-x86_64-mm-add-genapic_force.patch
revert-x86_64-mm-fix-the-irqbalance-quirk-for-e7320-e7520-e7525.patch
x86_64-fix-boot-hang-due-to-nmi-watchdog-init-code-tidy.patch
x86_64-fix-boot-hang-due-to-nmi-watchdog-init-code-tidy-tidy-2.patch
touchkit-ps-2-touchscreen-driver.patch
node-aware-skb-allocation-fix-for-device-tree-changes.patch
congestion-wait-dont-wait-when-there-are-no-pages-under-writeback.patch
slab-use-a-multiply-instead-of-a-divide-in-obj_to_index-tweaks.patch
deprecate-smbfs-in-favour-of-cifs.patch
edac-new-opteron-athlon64-memory-controller-driver.patch
drivers-add-lcd-support-3-Kconfig-fix.patch
drivers-add-lcd-support-workqueue-fixups.patch
touch_atime-cleanup.patch
ocfs2-relative-atime-support-tweaks.patch
optimize-o_direct-on-block-device-v3-tweak.patch
add-retain_initrd-boot-option-tweak.patch
workqueue-tweaks.patch
workqueue-dont-hold-workqueue_mutex-in-flush_scheduled_work.patch
implement-flush_work.patch
aio-use-flush_work.patch
kblockd-use-flush_work.patch
relayfs-use-flush_keventd_work.patch
tg3-use-flush_keventd_work.patch
e1000-use-flush_keventd_work.patch
libata-use-flush_work.patch
phy-use-flush_work.patch
bridge-avoid-using-noautorel-workqueues.patch
io-accounting-core-statistics.patch
clean-up-__set_page_dirty_nobuffers.patch
io-accounting-write-accounting.patch
io-accounting-write-cancel-accounting.patch
io-accounting-read-accounting-2.patch
io-accounting-read-accounting-nfs-fix.patch
io-accounting-read-accounting-cifs-fix.patch
io-accounting-direct-io.patch
io-accounting-report-in-procfs.patch
cleanup-taskstatsh.patch
io-accounting-via-taskstats.patch
getdelays-various-fixes.patch
io-accounting-add-to-getdelays.patch
move-page-writeback-acounting-out-of-macros.patch
per-backing_dev-dirty-and-writeback-page-accounting.patch
ext2-reservations.patch
bug-test-1.patch
sched-add-option-to-serialize-load-balancing-fix.patch
kernel-schedc-whitespace-cleanups-more.patch
sched2-sched-domain-sysctl-use-ctl_unnumbered.patch
mm-implement-swap-prefetching-use-ctl_unnumbered.patch
swap_prefetch-vs-zoned-counters.patch
add-include-linux-freezerh-and-move-definitions-from-prefetch.patch
readahead-kconfig-options-fix.patch
readahead-minmax_ra_pages.patch
readahead-sysctl-parameters.patch
readahead-sysctl-parameters-use-ctl_unnumbered.patch
readahead-context-based-method-locking-fix.patch
readahead-context-based-method-locking-fix-2.patch
readahead-call-scheme-ifdef-fix.patch
readahead-call-scheme-build-fix.patch
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resier4-add-include-linux-freezerh-and-move-definitions-from.patch
make-kmem_cache_destroy-return-void-reiser4.patch
reiser4-hardirq-include-fix.patch
reiser4-run-truncate_inode_pages-in-reiser4_delete_inode.patch
reiser4-get_sb_dev-fix.patch
reiser4-vs-zoned-allocator.patch
reiser4-temp-fix.patch
reiser4-kmem_cache_t-removal.patch
hpt3xx-rework-rate-filtering-tidy.patch
jmicron-warning-fix.patch
md-allow-reads-that-have-bypassed-the-cache-to-be-retried-on-failure-fix.patch
statistics-infrastructure-fix-buffer-overflow-in-histogram-with-linear-tidy.patch
extend-notifier_call_chain-to-count-nr_calls-made.patch
extend-notifier_call_chain-to-count-nr_calls-made-fixes-2.patch
define-and-use-new-eventscpu_lock_acquire-and-cpu_lock_release-fix.patch
eliminate-lock_cpu_hotplug-in-kernel-schedc-fix.patch
gtod-persistent-clock-support-i386.patch
hrtimers-clean-up-locking-fix.patch
updated-hrtimers-state-tracking.patch
updated-i386-convert-to-clock-event-devices.patch
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updated-gtod-mark-tsc-unusable-for-highres-timers.patch
round_jiffies-infrastructure-fix.patch
clocksource-small-cleanup-2-fix.patch
kvm-make-the-vcpu-execution-loop-an-arch-operation-build-fix.patch
kvm-make-__set_efer-an-arch-operation-build-fix.patch
slim-main-include-fix.patch
nr_blockdev_pages-in_interrupt-warning.patch
device-suspend-debug.patch
mutex-subsystem-synchro-test-module-fix.patch
slab-leaks3-default-y.patch
x86-kmap_atomic-debugging.patch
vdso-print-fatal-signals-use-ctl_unnumbered.patch
restore-rogue-readahead-printk.patch
put_bh-debug.patch
e1000-printk-warning-fixes.patch
acpi_format_exception-debug.patch
add-debugging-aid-for-memory-initialisation-problems-fix.patch
zeromap_pte_range-debug.patch
squash-ipc-warnings.patch
squash-udf-warnings.patch
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