12 May, 2009
1 commit
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Current bio_vec array index out-of-bounds test within
__end_that_request_first() does not seem correct.
It checks bio->bi_idx against bio->bi_vcnt, but the subsequent code
uses idx (which is, bio->bi_idx + next_idx) as the array index into
bio_vec array. This means that the test really make sense only at
the first iteration of !(nr_bytes >=bio->bi_size) case (when next_idx
== zero). Fix this by replacing bio->bi_idx with idx.
(This patch applies to 2.6.30-rc4.)Signed-off-by: Kazuhisa Ichikawa
Signed-off-by: Jens Axboe
24 Apr, 2009
5 commits
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Currently we look it up from ->ioprio, but ->ioprio can change if
either the process gets its IO priority changed explicitly, or if
cfq decides to temporarily boost it. So if we are unlucky, we can
end up attempting to remove a node from a different rbtree root than
where it was added.Fix this by using ->org_ioprio as the prio_tree index, since that
will only change for explicit IO priority settings (not for a boost).
Additionally cache the rbtree root inside the cfqq, then we don't have
to add code to reinsert the cfqq in the prio_tree if IO priority changes.Signed-off-by: Jens Axboe
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cfq_prio_tree_lookup() should return the direct match, yet it always
returns zero. Fix that.cfq_prio_tree_add() assumes that we don't get a direct match, while
it is very possible that we do. Using O_DIRECT, you can have different
cfqq with matching requests, since you don't have the page cache
to serialize things for you. Fix this bug by only adding the cfqq if
there isn't an existing match.Signed-off-by: Jens Axboe
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Not strictly needed, but we should make it clear that we init the
rbtree roots here.Signed-off-by: Jens Axboe
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Very rarely under stress testing of dm, oopses are occuring as
something tampers with an old stack frame. This has been traced back
to blk_abort_queue() leaving a timeout_list pointing to the stack.
The reason is that sometimes blk_abort_request() won't delete the
timer (if the request is marked as complete but before the timer has
been removed, a small race window). Fix this by splicing back from
the ususally empty list to the q->timeout_list.Signed-off-by: Hannes Reinecke
Signed-off-by: Jens Axboe -
This simplifies I/O stat accounting switching code and separates it
completely from I/O scheduler switch code.Requests are accounted according to the state of their request queue
at the time of the request allocation. There is no need anymore to
flush the request queue when switching I/O accounting state.Signed-off-by: Jerome Marchand
Signed-off-by: Jens Axboe
22 Apr, 2009
6 commits
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If the cfq io context doesn't have enough samples yet to provide a mean
seek distance, then use the default threshold we have for seeky IO instead
of defaulting to 0.Signed-off-by: Jeff Moyer
Signed-off-by: Jens Axboe -
Right now, depending on the first sector to which a process issues I/O,
the seek time may start out way out of whack. So make sure we start
with 0 sectors in seek, instead of the offset of the first request
issued.Signed-off-by: Jeff Moyer
Signed-off-by: Jens Axboe -
There's nothing to do for those devices, since the timeout handling is
based on requests.Signed-off-by: Jens Axboe
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/proc/diskstats used to show stats for all disks whether they're
zero-sized or not and their non-zero partitions. Commit
074a7aca7afa6f230104e8e65eba3420263714a5 accidentally changed the
behavior such that it doesn't print out zero sized disks. This patch
implements DISK_PITER_INCL_EMPTY_PART0 flag to partition iterator and
uses it in diskstats_show() such that empty part0 is shown in
/proc/diskstats.Reported and bisectd by Dianel Collins.
Signed-off-by: Tejun Heo
Reported-by: Daniel Collins
Signed-off-by: Jens Axboe -
Impact: don't set GFP_DMA in q->bounce_gfp unnecessarily
All DMA address limits are expressed in terms of the last addressable
unit (byte or page) instead of one plus that. However, when
determining bounce_gfp for 64bit machines in blk_queue_bounce_limit(),
it compares the specified limit against 0x100000000UL to determine
whether it's below 4G ending up falsely setting GFP_DMA in
q->bounce_gfp.As DMA zone is very small on x86_64, this makes larger SG_IO transfers
very eager to trigger OOM killer. Fix it. While at it, rename the
parameter to @dma_mask for clarity and convert comment to proper
winged style.Signed-off-by: Tejun Heo
Signed-off-by: Jens Axboe -
Impact: fix SG_IO behavior such that it matches the documentation
SG_IO howto says that if ->dxfer_len and sum of iovec disagress, the
shorter one wins. However, the current implementation returns -EINVAL
for such cases. Trim iovc if it's longer than ->dxfer_len.This patch uses iov_*() helpers which take struct iovec * by casting
struct sg_iovec * to it. sg_iovec is always identical to iovec and
this will be further cleaned up with later patches.Signed-off-by: Tejun Heo
Signed-off-by: Jens Axboe
15 Apr, 2009
11 commits
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If we have processes that are working in close proximity to each
other on disk, we don't want to idle wait. Instead allow the close
process to issue a request, getting better aggregate bandwidth.
The anticipatory scheduler has similar checks, noop and deadline do
not need it since they don't care about process io mappings.The code for CFQ is a little more involved though, since we split
request queues into per-process contexts.This fixes a performance problem with eg dump(8), since it uses
several processes in some silly attempt to speed IO up. Even if
dump(8) isn't really a valid case (it should be fixed by using
CLONE_IO), there are other cases where we see close processes
and where idling ends up hurting performance.Credit goes to Jeff Moyer for writing the
initial implementation.Signed-off-by: Jens Axboe
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Makes it easier to read the traces.
Signed-off-by: Jens Axboe
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We only kick the dispatch for an idling queue, if we think it's a
(somewhat) fully merged request. Also allow a kick if we have other
busy queues in the system, since we don't want to risk waiting for
a potential merge in that case. It's better to get some work done and
proceed.Signed-off-by: Jens Axboe
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It's called from the workqueue handlers from process context, so
we always have irqs enabled when entered.Signed-off-by: Jens Axboe
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Remove code handling bio_alloc failure with __GFP_WAIT.
GFP_KERNEL implies __GFP_WAIT.Signed-off-by: Nikanth Karthikesan
Signed-off-by: Jens Axboe -
blk_rq_unmap_user() returns -EFAULT if a program passes an invalid
address to kernel. SG_IO path needs to pass the returned value to user
space instead of ignoring it.Signed-off-by: FUJITA Tomonori
Signed-off-by: Jens Axboe -
"Zhang, Yanmin" reports that commit
b029195dda0129b427c6e579a3bb3ae752da3a93 introduced a regression
of about 50% with sequential threaded read workloads. The test
case is:tiotest -k0 -k1 -k3 -f 80 -t 32
which starts 32 threads each reading a 80MB file. Twiddle the kick
queue logic so that we do start IO immediately, if it appears to be
a fully merged request. We can't really detect that, so just check
if the request is bigger than a page or not. The assumption is that
since single bio issues will first queue a single request with just
one page attached and then later do merges on that, if we already
have more than a page worth of data in the request, then the request
is most likely good to go.Verified that this doesn't cause a regression with the test case that
commit b029195dda0129b427c6e579a3bb3ae752da3a93 was fixing. It does not,
we still see maximum sized requests for the queue-then-merge cases.Signed-off-by: Jens Axboe
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We can just use the block layer BLK_RW_SYNC/ASYNC defines now.
Signed-off-by: Jens Axboe
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We can just use the block layer BLK_RW_SYNC/ASYNC defines now.
Signed-off-by: Jens Axboe
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Signed-off-by: Jens Axboe
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Credit goes to Andrew Morton for spotting this one.
Signed-off-by: Jens Axboe
08 Apr, 2009
2 commits
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…nel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
branch tracer, intel-iommu: fix build with CONFIG_BRANCH_TRACER=y
branch tracer: Fix for enabling branch profiling makes sparse unusable
ftrace: Correct a text align for event format output
Update /debug/tracing/README
tracing/ftrace: alloc the started cpumask for the trace file
tracing, x86: remove duplicated #include
ftrace: Add check of sched_stopped for probe_sched_wakeup
function-graph: add proper initialization for init task
tracing/ftrace: fix missing include string.h
tracing: fix incorrect return type of ns2usecs()
tracing: remove CALLER_ADDR2 from wakeup tracer
blktrace: fix pdu_len when tracing packet command requests
blktrace: small cleanup in blk_msg_write()
blktrace: NUL-terminate user space messages
tracing: move scripts/trace/power.pl to scripts/tracing/power.pl -
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
loop: mutex already unlocked in loop_clr_fd()
cfq-iosched: don't let idling interfere with plugging
block: remove unused REQ_UNPLUG
cfq-iosched: kill two unused cfqq flags
cfq-iosched: change dispatch logic to deal with single requests at the time
mflash: initial support
cciss: change to discover first memory BAR
cciss: kernel scan thread for MSA2012
cciss: fix residual count for block pc requests
block: fix inconsistency in I/O stat accounting code
block: elevator quiescing helpers
07 Apr, 2009
8 commits
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* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
sata_mv: shorten register names
sata_mv: workaround errata SATA#13
sata_mv: cosmetic renames
sata_mv: workaround errata SATA#26
sata_mv: workaround errata PCI#7
sata_mv: replace 0x1f with ATA_PIO4 (v2)
sata_mv: fix irq mask races
sata_mv: revert SoC irq breakage
libata: ahci enclosure management bios workaround
ata: Add TRIM infrastructure
ata_piix: VGN-BX297XP wants the controller power up on suspend
libata: Remove some redundant casts from pata_octeon_cf.c
pata_artop: typo -
When CFQ is waiting for a new request from a process, currently it'll
immediately restart queuing when it sees such a request. This doesn't
work very well with streamed IO, since we then end up splitting IO
that would otherwise have been merged nicely. For a simple dd test,
this causes 10x as many requests to be issued as we should have.
Normally this goes unnoticed due to the low overhead of requests
at the device side, but some hardware is very sensitive to request
sizes and there it can cause big slow downs.Signed-off-by: Jens Axboe
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The request inherits the unplug flag from the bio, but it isn't actually
used. The bio flag stops at __make_request(), which tells it to unplug
after submission. Passing it on to the request doesn't make any sense.Signed-off-by: Jens Axboe
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We only manipulate the must_dispatch and queue_new flags, they are not
tested anymore. So get rid of them.Signed-off-by: Jens Axboe
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The IO scheduler core calls into the IO scheduler dispatch_request hook
to move requests from the IO scheduler and into the driver dispatch
list. It only does so when the dispatch list is empty. CFQ moves several
requests to the dispatch list, which can cause higher latencies if we
suddenly have to switch to some important sync IO. Change the logic to
move one request at the time instead.This should almost be functionally equivalent to what we did before,
except that we now honor 'quantum' as the maximum queue depth at the
device side from any single cfqq. If there's just a single active
cfqq, we allow up to 4 times the normal quantum.Signed-off-by: Jens Axboe
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This forces in_flight to be zero when turning off or on the I/O stat
accounting and stops updating I/O stats in attempt_merge() when
accounting is turned off.Signed-off-by: Jerome Marchand
Signed-off-by: Jens Axboe -
Simple helper functions to quiesce the request queue. These are
currently only used for switching IO schedulers on-the-fly, but
we can use them to properly switch IO accounting on and off as well.Signed-off-by: Jerome Marchand
Signed-off-by: Jens Axboe -
Fix a typo (this was in the original patch but was not merged when the code
fixes were for some reason)Signed-off-by: Alan Cox
Signed-off-by: Jeff Garzik
06 Apr, 2009
5 commits
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By default, CFQ will anticipate more IO from a given io context if the
previously completed IO was sync. This used to be fine, since the only
sync IO was reads and O_DIRECT writes. But with more "normal" sync writes
being used now, we don't want to anticipate for those.Add a bio/request flag that informs the IO scheduler that this is a sync
request that we should not idle for. Introduce WRITE_ODIRECT specifically
for O_DIRECT writes, and make sure that the other sync writes set this
flag.Signed-off-by: Jens Axboe
Signed-off-by: Linus Torvalds -
For the older SSD devices that don't do command queuing, we do want to
enable plugging to get better merging.Signed-off-by: Jens Axboe
Signed-off-by: Linus Torvalds -
This makes sure that we never wait on async IO for sync requests, instead
of doing the split on writes vs reads.Signed-off-by: Jens Axboe
Signed-off-by: Linus Torvalds -
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
tracing, net: fix net tree and tracing tree merge interaction
tracing, powerpc: fix powerpc tree and tracing tree interaction
ring-buffer: do not remove reader page from list on ring buffer free
function-graph: allow unregistering twice
trace: make argument 'mem' of trace_seq_putmem() const
tracing: add missing 'extern' keywords to trace_output.h
tracing: provide trace_seq_reserve()
blktrace: print out BLK_TN_MESSAGE properly
blktrace: extract duplidate code
blktrace: fix memory leak when freeing struct blk_io_trace
blktrace: fix blk_probes_ref chaos
blktrace: make classic output more classic
blktrace: fix off-by-one bug
blktrace: fix the original blktrace
blktrace: fix a race when creating blk_tree_root in debugfs
blktrace: fix timestamp in binary output
tracing, Text Edit Lock: cleanup
tracing: filter fix for TRACE_EVENT_FORMAT events
ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
x86: kretprobe-booster interrupt emulation code fix
...Fix up trivial conflicts in
arch/parisc/include/asm/ftrace.h
include/linux/memory.h
kernel/extable.c
kernel/module.c -
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask: (36 commits)
cpumask: remove cpumask allocation from idle_balance, fix
numa, cpumask: move numa_node_id default implementation to topology.h, fix
cpumask: remove cpumask allocation from idle_balance
x86: cpumask: x86 mmio-mod.c use cpumask_var_t for downed_cpus
x86: cpumask: update 32-bit APM not to mug current->cpus_allowed
x86: microcode: cleanup
x86: cpumask: use work_on_cpu in arch/x86/kernel/microcode_core.c
cpumask: fix CONFIG_CPUMASK_OFFSTACK=y cpu hotunplug crash
numa, cpumask: move numa_node_id default implementation to topology.h
cpumask: convert node_to_cpumask_map[] to cpumask_var_t
cpumask: remove x86 cpumask_t uses.
cpumask: use cpumask_var_t in uv_flush_tlb_others.
cpumask: remove cpumask_t assignment from vector_allocation_domain()
cpumask: make Xen use the new operators.
cpumask: clean up summit's send_IPI functions
cpumask: use new cpumask functions throughout x86
x86: unify cpu_callin_mask/cpu_callout_mask/cpu_initialized_mask/cpu_sibling_setup_mask
cpumask: convert struct cpuinfo_x86's llc_shared_map to cpumask_var_t
cpumask: convert node_to_cpumask_map[] to cpumask_var_t
x86: unify 32 and 64-bit node_to_cpumask_map
...
04 Apr, 2009
1 commit
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* 'ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
s390: remove arch specific smp_send_stop()
panic: clean up kernel/panic.c
panic, smp: provide smp_send_stop() wrapper on UP too
panic: decrease oops_in_progress only after having done the panic
generic-ipi: eliminate WARN_ON()s during oops/panic
generic-ipi: cleanups
generic-ipi: remove CSD_FLAG_WAIT
generic-ipi: remove kmalloc()
generic IPI: simplify barriers and locking
03 Apr, 2009
1 commit
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Impact: output all of packet commands - not just the first 4 / 8 bytes
Since commit d7e3c3249ef23b4617393c69fe464765b4ff1645 ("block: add
large command support"), struct request->cmd has been changed from
unsinged char cmd[BLK_MAX_CDB] to unsigned char *cmd.v1 -> v2: by: FUJITA Tomonori
- make sure rq->cmd_len is always intialized, and then we can use
rq->cmd_len instead of BLK_MAX_CDB.Signed-off-by: Li Zefan
Acked-by: FUJITA Tomonori
Cc: Arnaldo Carvalho de Melo
Cc: Steven Rostedt
Cc: Frederic Weisbecker
Cc: Jens Axboe
LKML-Reference:
Signed-off-by: Ingo Molnar
