We avoid evicting and scanning anonymous pages for the most part, but
under some workloads we can end up with most of memory filled with
anonymous pages. At that point, we suddenly need to clear the referenced
bits on all of memory, which can take ages on very large memory systems.
We can reduce the maximum number of pages that need to be scanned by not
taking the referenced state into account when deactivating an anonymous
page. After all, every anonymous page starts out referenced, so why
check?
If an anonymous page gets referenced again before it reaches the end of
the inactive list, we move it back to the active list.
To keep the maximum amount of necessary work reasonable, we scale the
active to inactive ratio with the size of memory, using the formula
active:inactive ratio = sqrt(memory in GB * 10).
Kswapd CPU use now seems to scale by the amount of pageout bandwidth,
instead of by the amount of memory present in the system.
[kamezawa.hiroyu@jp.fujitsu.com: fix OOM with memcg]
[kamezawa.hiroyu@jp.fujitsu.com: memcg: lru scan fix]
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Split the LRU lists in two, one set for pages that are backed by real file
systems ("file") and one for pages that are backed by memory and swap
("anon"). The latter includes tmpfs.
The advantage of doing this is that the VM will not have to scan over lots
of anonymous pages (which we generally do not want to swap out), just to
find the page cache pages that it should evict.
This patch has the infrastructure and a basic policy to balance how much
we scan the anon lists and how much we scan the file lists. The big
policy changes are in separate patches.
[lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset]
[kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru]
[kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page]
[hugh@veritas.com: memcg swapbacked pages active]
[hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED]
[akpm@linux-foundation.org: fix /proc/vmstat units]
[nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration]
[kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo]
[kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()]
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Define page_file_cache() function to answer the question:
is page backed by a file?
Originally part of Rik van Riel's split-lru patch. Extracted to make
available for other, independent reclaim patches.
Moved inline function to linux/mm_inline.h where it will be needed by
subsequent "split LRU" and "noreclaim" patches.
Unfortunately this needs to use a page flag, since the PG_swapbacked state
needs to be preserved all the way to the point where the page is last
removed from the LRU. Trying to derive the status from other info in the
page resulted in wrong VM statistics in earlier split VM patchsets.
The total number of page flags in use on a 32 bit machine after this patch
is 19.
[akpm@linux-foundation.org: fix up out-of-order merge fallout]
[hugh@veritas.com: splitlru: shmem_getpage SetPageSwapBacked sooner[
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: MinChan Kim <minchan.kim@gmail.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If vm_swap_full() (swap space more than 50% full), the system will free
swap space at swapin time. With this patch, the system will also free the
swap space in the pageout code, when we decide that the page is not a
candidate for swapout (and just wasting swap space).
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: MinChan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Turn the pagevecs into an array just like the LRUs. This significantly
cleans up the source code and reduces the size of the kernel by about 13kB
after all the LRU lists have been created further down in the split VM
patch series.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we are defining explicit variables for the inactive and active
list. An indexed array can be more generic and avoid repeating similar
code in several places in the reclaim code.
We are saving a few bytes in terms of code size:
Before:
text data bss dec hex filename
4097753 573120 4092484 8763357 85b7dd vmlinux
After:
text data bss dec hex filename
4097729 573120 4092484 8763333 85b7c5 vmlinux
Having an easy way to add new lru lists may ease future work on the
reclaim code.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On large memory systems, the VM can spend way too much time scanning
through pages that it cannot (or should not) evict from memory. Not only
does it use up CPU time, but it also provokes lock contention and can
leave large systems under memory presure in a catatonic state.
This patch series improves VM scalability by:
1) putting filesystem backed, swap backed and unevictable pages
onto their own LRUs, so the system only scans the pages that it
can/should evict from memory
2) switching to two handed clock replacement for the anonymous LRUs,
so the number of pages that need to be scanned when the system
starts swapping is bound to a reasonable number
3) keeping unevictable pages off the LRU completely, so the
VM does not waste CPU time scanning them. ramfs, ramdisk,
SHM_LOCKED shared memory segments and mlock()ed VMA pages
are keept on the unevictable list.
This patch:
isolate_lru_page logically belongs to be in vmscan.c than migrate.c.
It is tough, because we don't need that function without memory migration
so there is a valid argument to have it in migrate.c. However a
subsequent patch needs to make use of it in the core mm, so we can happily
move it to vmscan.c.
Also, make the function a little more generic by not requiring that it
adds an isolated page to a given list. Callers can do that.
Note that we now have '__isolate_lru_page()', that does
something quite different, visible outside of vmscan.c
for use with memory controller. Methinks we need to
rationalize these names/purposes. --lts
[akpm@linux-foundation.org: fix mm/memory_hotplug.c build]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (94 commits)
USB: remove err() macro from more usb drivers
USB: remove err() macro from usb misc drivers
USB: remove err() macro from usb core code
USB: remove err() macro from usb class drivers
USB: remove use of err() in drivers/usb/serial
USB: remove info() macro from usb mtd drivers
USB: remove info() macro from usb input drivers
USB: remove info() macro from usb network drivers
USB: remove info() macro from remaining usb drivers
USB: remove info() macro from usb/misc drivers
USB: remove info() macro from usb/serial drivers
USB: remove warn macro from HID core
USB: remove warn() macro from usb drivers
USB: remove warn() macro from usb net drivers
USB: remove warn() macro from usb media drivers
USB: remove warn() macro from usb input drivers
usb/fsl_qe_udc: clear data toggle on clear halt request
usb/fsl_qe_udc: fix response to get status request
fsl_usb2_udc: Fix oops on probe failure.
fsl_usb2_udc: Add a wmb before priming endpoint.
...
* 'drm-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (44 commits)
drm/i915: fix ioremap of a user address for non-root (CVE-2008-3831)
drm: make CONFIG_DRM depend on CONFIG_SHMEM.
radeon: fix PCI bus mastering support enables.
radeon: add RS400 family support.
drm/radeon: add support for RS740 IGP chipsets.
i915: GM45 has GM965-style MCH setup.
i915: Don't run retire work handler while suspended
i915: Map status page cached for chips with GTT-based HWS location.
i915: Fix up ring initialization to cover G45 oddities
i915: Use non-reserved status page index for breadcrumb
drm: Increment dev_priv->irq_received so i915_gem_interrupts count works.
drm: kill drm_device->irq
drm: wbinvd is cache coherent.
i915: add missing return in error path.
i915: fixup permissions on gem ioctls.
drm: Clean up many sparse warnings in i915.
drm: Use ioremap_wc in i915_driver instead of ioremap, since we always want WC.
drm: G33-class hardware has a newer 965-style MCH (no DCC register).
drm: Avoid oops in GEM execbuffers with bad arguments.
DRM: Return -EBADF on bad object in flink, and return curent name if it exists.
...
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (95 commits)
V4L/DVB (9296): Patch to remove warning message during cx88-dvb compilation
V4L/DVB (9294): gspca: Add a stop sequence in t613.
V4L/DVB (9293): gspca: Separate and fix the sensor dependant sequences in t613.
V4L/DVB (9292): gspca: Call the control setting functions at init time in t613.
V4L/DVB (9291): gspca: Do not set the white balance temperature by default in t613.
V4L/DVB (9290): gspca: Adjust the sensor init sequences in t613.
V4L/DVB (9289): gspca: Other sensor identified as om6802 in t613.
V4L/DVB (9288): gspca: Write to the USB device and not USB interface in t613.
V4L/DVB (9287): gspca: Change the name of the multi bytes write function in t613.
V4L/DVB (9286): gspca: Compilation problem of gspca.c and the kernel version.
V4L/DVB (9283): Correct typo and enable setting the gain on the mt9m111 sensor
V4L/DVB (9282): Properly iterate the urbs when destroying them.
V4L/DVB (9281): gspca: Add hflip and vflip to the po1030 sensor
V4L/DVB (9280): gspca: Use the gspca debug macros
V4L/DVB (9279): gspca: Correct some copyright headers
V4L/DVB (9278): gspca: Remove the m5602_debug variable
V4L/DVB (9277): gspca: propagate an error in m5602_start_transfer()
V4L/DVB (9276): videobuf-dvb: two functions are now static
V4L/DVB (9275): dvb: input data pointer of cx24116_writeregN() should be const
V4L/DVB (9274): Remove spurious messages and turn into debug.
...
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: Remove automatic enabling of the HUGE_FILE feature flag
ext4: Replace hackish ext4_mb_poll_new_transaction with commit callback
ext4: Update Documentation/filesystems/ext4.txt
ext4: Remove unused mount options: nomballoc, mballoc, nocheck
ext4: Remove compile warnings when building w/o CONFIG_PROC_FS
ext4: Add missing newlines to printk messages
ext4: Fix file fragmentation during large file write.
vfs: Add no_nrwrite_index_update writeback control flag
vfs: Remove the range_cont writeback mode.
ext4: Use tag dirty lookup during mpage_da_submit_io
ext4: let the block device know when unused blocks can be discarded
ext4: Don't reuse released data blocks until transaction commits
ext4: Use an rbtree for tracking blocks freed during transaction.
ext4: Do mballoc init before doing filesystem recovery
ext4: Free ext4_prealloc_space using kmem_cache_free
ext4: Fix Kconfig typo for ext4dev
ext4: Remove an old reference to ext4dev in Makefile comment
This extends the anchor API as btusb needs for autosuspend.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds the vstusb driver to the drivers/usb/misc directory.
This driver provides support for Vernier Software & Technology
spectrometers, all made by Ocean Optics. The driver provides both IOCTL
and read()/write() methods for sending raw data to spectrometers across
the bulk channel. Each method allows for a configured timeout.
From: Stephen Ware <stephen.ware@eqware.net>
Signed-off-by: Dennis O'Brien <dennis.obrien@eqware.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fixes a minor typo in the comments for usb_set_serial_data.
Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The following patch introduces a new f_obex.c function driver.
It allows userspace obex servers to use usb as transport layer
for their messages.
[ dbrownell@users.sourceforge.net: various fixes and cleanups ]
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add a new mechanism to the composite gadget framework, letting
functions deactivate (and reactivate) themselves. Think of it
as a refcounted wrapper for the software pullup control.
A key example of why to use this mechanism involves functions that
require a userspace daemon. Those functions shuld use this new
mechanism to prevent the gadget from enumerating until those daemons
are activated. Without this mechanism, hosts would see devices that
malfunction until the relevant daemons start.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
this extends the poisoning concept to anchors. This way poisoning
will work with fire and forget drivers.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
looking at usb_kill_urb() it seems to me that it is unnecessarily lenient.
In the use case of disconnect() you never want to use the URB again
(for the same device) But leaving urb->reject elevated will make it easier
to avoid races between read/write and disconnect.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This driver was originaly written by Stefan Kopp, but massively
reworked by Greg for submission.
Thanks to Felipe Balbi <me@felipebalbi.com> for lots of work in cleaning
up this driver.
Thanks to Oliver Neukum <oliver@neukum.org> for reviewing previous
versions and pointing out problems.
Cc: Stefan Kopp <stefan_kopp@agilent.com>
Cc: Marcel Janssen <korgull@home.nl>
Cc: Felipe Balbi <me@felipebalbi.com>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Someone noticed these registers moved around for later chips,
so we redo the codepaths per-chip. PCIE chips don't appear to
require explicit enables.
Signed-off-by: Dave Airlie <airlied@redhat.com>
This should improve performance by avoiding uncached reads by the CPU (the
point of having a status page), and may improve stability. This patch only
affects G33, GM45 and G45 chips as those are the only ones using GTT-based
HWS mappings.
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Like the last patch but adds a macro to get at the irq value instead of
dereferencing pdev directly. Should make things easier for the BSD guys and
if we ever support non-PCI devices.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
GEM allows the creation of persistent buffer objects accessible by the
graphics device through new ioctls for managing execution of commands on the
device. The userland API is almost entirely driver-specific to ensure that
any driver building on this model can easily map the interface to individual
driver requirements.
GEM is used by the 2d driver for managing its internal state allocations and
will be used for pixmap storage to reduce memory consumption and enable
zero-copy GLX_EXT_texture_from_pixmap, and in the 3d driver is used to enable
GL_EXT_framebuffer_object and GL_ARB_pixel_buffer_object.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Previously, drivers supporting vblank interrupt waits would run the interrupt
all the time, or all the time that any 3d client was running, preventing the
CPU from sleeping for long when the system was otherwise idle. Now, interrupts
are disabled any time that no client is waiting on a vblank event. The new
method uses vblank counters on the chipsets when the interrupts are turned
off, rather than counting interrupts, so that we can continue to present
accurate vblank numbers.
Co-author: Michel Dänzer <michel@tungstengraphics.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
There is no point in considering FreeBSD et al. in the linux kernel
source code.
Signed-off-by: Carlos R. Mafra <crmafra@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This patch marks those two functions as static:
static int videobuf_dvb_register_adapter(struct videobuf_dvb_frontends *fe,
static int videobuf_dvb_register_frontend(struct dvb_adapter *adapter,
Since MFE patches changed their calls by videobuf_dvb_register_bus.
To avoid having to declare the prototypes, the patch moves
videobuf_dvb_register_bus() to be after the declaration of the above functions
used there.
Cc: Steven Toth <stoth@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
To optimise data storage even further one other redundant
var has been removed.
This also removes a redundant assignment.
Signed-off-by: Steven Toth <stoth@linuxtv.org>
Signed-off-by: Darron Broad <darron@kewl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This tuner was already supported by proxy as an FMD1216ME, however,
the MEX uses a different FM Radio IF so this addition is now required.
Signed-off-by: Darron Broad <darron@kewl.org>
Signed-off-by: Steven Toth <stoth@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
To optimise data storage redundant vars are removed.
Signed-off-by: Darron Broad <darron@kewl.org>
Signed-off-by: Steven Toth <stoth@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Switching sensors on and off is now done by sensor drivers themselves,
typically using platform-provided hooks. Update soc_camera_platform.c to
do the same. Also remove a refundant struct soc_camera_platform_info
definition from soc_camera_platform.c.
Tested-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This add frontend R/W mutual exclusion.
Prior to this point in time it was possible to open both
frontends simultaneously which an MFE card cannot support.
In order to stop this, a delayed open is performed which
has the following function:
- Return EBUSY after a configurable amount of time
if a frontend is unavailable due to the other being
in use.
- Only allow opening of a frontend if the kernel thread
of the other has stopped.
This solution was chosen to allow switching between
frontends to work as seamlessly as possible. When both
frontends are actually opened simultaneously then one
will only open, but if quick switching is performed
between one of many then the new open will succeed in
a clean fashion rather than interrupting a kernel
thread.
Signed-off-by: Darron Broad <darron@kewl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This adds a configurable (one per card) gate control option
for multi-frontend. Prior to this point gate control was
assumed to be on the primary frontend, this is a fault
when the gate to the analogue section is on the secondary
which is the default for both the HVR-3000 and HVR-4000
in MFE.
Signed-off-by: Darron Broad <darron@kewl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
A detailed description from the original patches 2 years ago:
"The WinTV-HVR3000 has a single transport bus which is shared between
a DVB-T and DVB-S modulator. These patches build on the bus acquisition
cx88 work from a few weeks ago to add support for this.
So to applications the HVR3000 looks like this:
/dev/dvb/adapter0/fe0 (cx24123 DVB-S demod)
/dev/dvb/adapter0/fe1 (cx22702 DVB-T demod)
Additional boards continue as before, eg:
/dev/dvb/adapter1/fe0 (lgdt3302 ATSC demod)
The basic change is removing the single instance of the videobuf_dvb in
cx8802_dev and saa7134_dev(?) and replacing it with a list and some
supporting functions.
*NOTE* This branch was taken before v4l-dvb was closed for 2.6.19 so
two or three current cx88 patches appear to be reversed by this tree,
this will be cleaned up in the near future. The patches missing change
the mutex handing to core->lock, fix an enumeration problem."
It should be recognised that a number of people have been maintaining
this patchset. Significant levels of Kudos to everyone one involved,
including but not limited to:
Darron Broad
Fabio M. Di Nitto
Carlo Scarfoglio
Hans Werner
Without the work of these people, and countless others, my two year old
patches would of died on the Mercurial linuxtv.org vine a long time
ago.
TODO: Revise these patches a little further so that the need for
demux1 and dvr0 is optional, not mandatory on the HVR3000.
HISTORY (darron):
This is the last update to MFE prepared by Hans which is based
upon the `scratchpad' diff created by Carlo.
All MFE work prior to that point must be attributed to Fabio
who ported and maintained Steve's original patch up to that
time.
Signed-off-by: Steven Toth <stoth@linuxtv.org>
Signed-off-by: Darron Broad <darron@kewl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Looking at these headers as they appear in the kernel makes you
wonder why it is done that way. Refer to the v4l-dvb repository
where the full unstripped header can be found to understand the
reasoning behind this.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
block: remove __generic_unplug_device() from exports
block: move q->unplug_work initialization
blktrace: pass zfcp driver data
blktrace: add support for driver data
block: fix current kernel-doc warnings
block: only call ->request_fn when the queue is not stopped
block: simplify string handling in elv_iosched_store()
block: fix kernel-doc for blk_alloc_devt()
block: fix nr_phys_segments miscalculation bug
block: add partition attribute for partition number
block: add BIG FAT WARNING to CONFIG_DEBUG_BLOCK_EXT_DEVT
softirq: Add support for triggering softirq work on softirqs.
This patch adds the new api call blk_add_driver_data() to blktrace.
It allows to trace device driver-specific binary data.
Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This fixes the bug reported by Nikanth Karthikesan <knikanth@suse.de>:
http://lkml.org/lkml/2008/10/2/203
The root cause of the bug is that blk_phys_contig_segment
miscalculates q->max_segment_size.
blk_phys_contig_segment checks:
req->biotail->bi_size + next_req->bio->bi_size > q->max_segment_size
But blk_recalc_rq_segments might expect that req->biotail and the
previous bio in the req are supposed be merged into one
segment. blk_recalc_rq_segments might also expect that next_req->bio
and the next bio in the next_req are supposed be merged into one
segment. In such case, we merge two requests that can't be merged
here. Later, blk_rq_map_sg gives more segments than it should.
We need to keep track of segment size in blk_recalc_rq_segments and
use it to see if two requests can be merged. This patch implements it
in the similar way that we used to do for hw merging (virtual
merging).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This is basically a genericization of Jens Axboe's block layer
remote softirq changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
