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  1. 13 2月, 2014 17 次提交
  3. 10 2月, 2014 1 次提交
    • A
      fix O_SYNC|O_APPEND syncing the wrong range on write() · d311d79d
      由 Al Viro 提交于 
      It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support)
when sync_page_range() had been introduced; generic_file_write{,v}() correctly
synced
	pos_after_write - written .. pos_after_write - 1
but generic_file_aio_write() synced
	pos_before_write .. pos_before_write + written - 1
instead.  Which is not the same thing with O_APPEND, obviously.
A couple of years later correct variant had been killed off when
everything switched to use of generic_file_aio_write().

All users of generic_file_aio_write() are affected, and the same bug
has been copied into other instances of ->aio_write().

The fix is trivial; the only subtle point is that generic_write_sync()
ought to be inlined to avoid calculations useless for the majority of
calls.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      d311d79d
  5. 07 2月, 2014 1 次提交
    • S
      swap: add a simple detector for inappropriate swapin readahead · 579f8290
      由 Shaohua Li 提交于 
      This is a patch to improve swap readahead algorithm.  It's from Hugh and
I slightly changed it.

Hugh's original changelog:

swapin readahead does a blind readahead, whether or not the swapin is
sequential.  This may be ok on harddisk, because large reads have
relatively small costs, and if the readahead pages are unneeded they can
be reclaimed easily - though, what if their allocation forced reclaim of
useful pages? But on SSD devices large reads are more expensive than
small ones: if the readahead pages are unneeded, reading them in caused
significant overhead.

This patch adds very simplistic random read detection.  Stealing the
PageReadahead technique from Konstantin Khlebnikov's patch, avoiding the
vma/anon_vma sophistications of Shaohua Li's patch, swapin_nr_pages()
simply looks at readahead's current success rate, and narrows or widens
its readahead window accordingly.  There is little science to its
heuristic: it's about as stupid as can be whilst remaining effective.

The table below shows elapsed times (in centiseconds) when running a
single repetitive swapping load across a 1000MB mapping in 900MB ram
with 1GB swap (the harddisk tests had taken painfully too long when I
used mem=500M, but SSD shows similar results for that).

Vanilla is the 3.6-rc7 kernel on which I started; Shaohua denotes his
Sep 3 patch in mmotm and linux-next; HughOld denotes my Oct 1 patch
which Shaohua showed to be defective; HughNew this Nov 14 patch, with
page_cluster as usual at default of 3 (8-page reads); HughPC4 this same
patch with page_cluster 4 (16-page reads); HughPC0 with page_cluster 0
(1-page reads: no readahead).

HDD for swapping to harddisk, SSD for swapping to VertexII SSD.  Seq for
sequential access to the mapping, cycling five times around; Rand for
the same number of random touches.  Anon for a MAP_PRIVATE anon mapping;
Shmem for a MAP_SHARED anon mapping, equivalent to tmpfs.

One weakness of Shaohua's vma/anon_vma approach was that it did not
optimize Shmem: seen below.  Konstantin's approach was perhaps mistuned,
50% slower on Seq: did not compete and is not shown below.

HDD        Vanilla Shaohua HughOld HughNew HughPC4 HughPC0
Seq Anon     73921   76210   75611   76904   78191  121542
Seq Shmem    73601   73176   73855   72947   74543  118322
Rand Anon   895392  831243  871569  845197  846496  841680
Rand Shmem 1058375 1053486  827935  764955  764376  756489

SSD        Vanilla Shaohua HughOld HughNew HughPC4 HughPC0
Seq Anon     24634   24198   24673   25107   21614   70018
Seq Shmem    24959   24932   25052   25703   22030   69678
Rand Anon    43014   26146   28075   25989   26935   25901
Rand Shmem   45349   45215   28249   24268   24138   24332

These tests are, of course, two extremes of a very simple case: under
heavier mixed loads I've not yet observed any consistent improvement or
degradation, and wider testing would be welcome.

Shaohua Li:

Test shows Vanilla is slightly better in sequential workload than Hugh's
patch.  I observed with Hugh's patch sometimes the readahead size is
shrinked too fast (from 8 to 1 immediately) in sequential workload if
there is no hit.  And in such case, continuing doing readahead is good
actually.

I don't prepare a sophisticated algorithm for the sequential workload
because so far we can't guarantee sequential accessed pages are swap out
sequentially.  So I slightly change Hugh's heuristic - don't shrink
readahead size too fast.

Here is my test result (unit second, 3 runs average):
	Vanilla		Hugh		New
Seq	356		370		360
Random	4525		2447		2444

Attached graph is the swapin/swapout throughput I collected with 'vmstat
2'.  The first part is running a random workload (till around 1200 of
the x-axis) and the second part is running a sequential workload.
swapin and swapout throughput are almost identical in steady state in
both workloads.  These are expected behavior.  while in Vanilla, swapin
is much bigger than swapout especially in random workload (because wrong
readahead).

Original patches by: Shaohua Li and Konstantin Khlebnikov.

[fengguang.wu@intel.com: swapin_nr_pages() can be static]
Signed-off-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NShaohua Li <shli@fusionio.com>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      579f8290
  7. 06 2月, 2014 4 次提交
  9. 05 2月, 2014 15 次提交
    • J
      wireless: sort and extend element ID list · 8c78e380
      由 Johannes Berg 提交于 
      The element ID list is currently almost sorted by amendment
or similar topic, but the order is difficult to maintain and
not very transparent. Sort the list by ID instead, and add
a lot of missing IDs.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      8c78e380
    • J
      cfg80211: regulatory introduce maximum bandwidth calculation · 97524820
      由 Janusz Dziedzic 提交于 
      In case we will get regulatory request with rule
where max_bandwidth_khz is set to 0 handle this
case as a special one.

If max_bandwidth_khz == 0 we should calculate maximum
available bandwidth base on all frequency contiguous rules.
In case we need auto calculation we just have to set:

country PL: DFS-ETSI
        (2402 - 2482 @ 40), (N/A, 20)
        (5170 - 5250 @ AUTO), (N/A, 20)
        (5250 - 5330 @ AUTO), (N/A, 20), DFS
        (5490 - 5710 @ 80), (N/A, 27), DFS

This mean we will calculate maximum bw for rules where
AUTO (N/A) were set, 160MHz (5330 - 5170) in example above.
So we will get:
        (5170 - 5250 @ 160), (N/A, 20)
        (5250 - 5330 @ 160), (N/A, 20), DFS

In other case:
country FR: DFS-ETSI
        (2402 - 2482 @ 40), (N/A, 20)
        (5170 - 5250 @ AUTO), (N/A, 20)
        (5250 - 5330 @ 80), (N/A, 20), DFS
        (5490 - 5710 @ 80), (N/A, 27), DFS

We will get 80MHz (5250 - 5170):
        (5170 - 5250 @ 80), (N/A, 20)
        (5250 - 5330 @ 80), (N/A, 20), DFS

Base on this calculations we will set correct channel
bandwidth flags (eg. IEEE80211_CHAN_NO_80MHZ).

We don't need any changes in CRDA or internal regulatory.
Signed-off-by: NJanusz Dziedzic <janusz.dziedzic@tieto.com>
[extend nl80211 description a bit, fix typo]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      97524820
    • M
      cfg80211: consider existing DFS interfaces · 9e0e2961
      由 Michal Kazior 提交于 
      It was possible to break interface combinations in
the following way:

 combo 1: iftype = AP, num_ifaces = 2, num_chans = 2,
 combo 2: iftype = AP, num_ifaces = 1, num_chans = 1, radar = HT20

With the above interface combinations it was
possible to:

 step 1. start AP on DFS channel by matching combo 2
 step 2. start AP on non-DFS channel by matching combo 1

This was possible beacuse (step 2) did not consider
if other interfaces require radar detection.

The patch changes how cfg80211 tracks channels -
instead of channel itself now a complete chandef
is stored.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      9e0e2961
    • A
      cfg80211: fix channel configuration in IBSS join · fe94f3a4
      由 Antonio Quartulli 提交于 
      When receiving an IBSS_JOINED event select the BSS object
based on the {bssid, channel} couple rather than the bssid
only.
With the current approach if another cell having the same
BSSID (but using a different channel) exists then cfg80211
picks up the wrong BSS object.
The result is a mismatching channel configuration between
cfg80211 and the driver, that can lead to any sort of
problem.

The issue can be triggered by having an IBSS sitting on
given channel and then asking the driver to create a new
cell using the same BSSID but with a different frequency.
By passing the channel to cfg80211_get_bss() we can solve
this ambiguity and retrieve/create the correct BSS object.
All the users of cfg80211_ibss_joined() have been changed
accordingly.

Moreover WARN when cfg80211_ibss_joined() gets a NULL
channel as argument and remove a bogus call of the same
function in ath6kl (it does not make sense to call
cfg80211_ibss_joined() with a zero BSSID on ibss-leave).

Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: Arend van Spriel <arend@broadcom.com>
Cc: Bing Zhao <bzhao@marvell.com>
Cc: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Cc: libertas-dev@lists.infradead.org
Acked-by: NKalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: NAntonio Quartulli <antonio@open-mesh.com>
[minor code cleanup in ath6kl]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      fe94f3a4
    • J
      mac80211: fix bufferable MMPDU RX handling · b4ba544c
      由 Johannes Berg 提交于 
      Action, disassoc and deauth frames are bufferable, and as such don't
have the PM bit in the frame control field reserved which means we
need to react to the bit when receiving in such a frame.

Fix this by introducing a new helper ieee80211_is_bufferable_mmpdu()
and using it for the RX path that currently ignores the PM bit in
any non-data frames for doze->wake transitions, but listens to it in
all frames for wake->doze transitions, both of which are wrong.

Also use the new helper in the TX path to clean up the code.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      b4ba544c
    • J
      nl80211: fix scheduled scan RSSI matchset attribute confusion · ea73cbce
      由 Johannes Berg 提交于 
      The scheduled scan matchsets were intended to be a list of filters,
with the found BSS having to pass at least one of them to be passed
to the host. When the RSSI attribute was added, however, this was
broken and currently wpa_supplicant adds that attribute in its own
matchset; however, it doesn't intend that to mean that anything
that passes the RSSI filter should be passed to the host, instead
it wants it to mean that everything needs to also have higher RSSI.

This is semantically problematic because we have a list of filters
like [ SSID1, SSID2, SSID3, RSSI ] with no real indication which
one should be OR'ed and which one AND'ed.

To fix this, move the RSSI filter attribute into each matchset. As
we need to stay backward compatible, treat a matchset with only the
RSSI attribute as a "default RSSI filter" for all other matchsets,
but only if there are other matchsets (an RSSI-only matchset by
itself is still desirable.)

To make driver implementation easier, keep a global min_rssi_thold
for the entire request as well. The only affected driver is ath6kl.

I found this when I looked into the code after Raja Mani submitted
a patch fixing the n_match_sets calculation to disregard the RSSI,
but that patch didn't address the semantic issue.
Reported-by: NRaja Mani <rmani@qti.qualcomm.com>
Acked-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      ea73cbce
    • J
      mac80211: add length check in ieee80211_is_robust_mgmt_frame() · d8ca16db
      由 Johannes Berg 提交于 
      A few places weren't checking that the frame passed to the
function actually has enough data even though the function
clearly documents it must have a payload byte. Make this
safer by changing the function to take an skb and checking
the length inside. The old version is preserved for now as
the rtl* drivers use it and don't have a correct skb.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      d8ca16db
    • J
      mac80211: remove module handling from rate control ops · cc01f9b5
      由 Johannes Berg 提交于 
      There's not a single rate control algorithm actually in
a separate module where the module refcount would be
required. Similarly, there's no specific rate control
module.

Therefore, all the module handling code in rate control
is really just dead code, so remove it.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      cc01f9b5
    • J
      mac80211: make rate control ops const · 631ad703
      由 Johannes Berg 提交于 
      Change the code to allow making all the rate control ops
const, nothing ever needs to change them. Also change all
drivers to make use of this and mark the ops const.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      631ad703
    • J
      nl80211: add Guard Interval support for set_bitrate_mask · 0b9323f6
      由 Janusz Dziedzic 提交于 
      Allow to force SGI, LGI.
Mainly for test purpose.
Signed-off-by: NJanusz Dziedzic <janusz.dziedzic@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      0b9323f6
    • J
      cfg80211: make connect ie param const · 4b5800fe
      由 Johannes Berg 提交于 
      This required liberally sprinkling 'const' over brcmfmac
and mwifiex but seems like a useful thing to do since the
pointer can't really be written.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      4b5800fe
    • J
      cfg80211: Clean up connect params and channel fetching · 664834de
      由 Jouni Malinen 提交于 
      Addition of the frequency hints showed up couple of places in cfg80211
where pointers could be marked const and a shared function could be used
to fetch a valid channel.
Signed-off-by: NJouni Malinen <j@w1.fi>
[fix mwifiex]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      664834de
    • J
      cfg80211: Advertise maximum associated STAs in AP mode · b43504cf
      由 Jouni Malinen 提交于 
      This allows drivers to advertise the maximum number of associated
stations they support in AP mode (including P2P GO). User space
applications can use this for cleaner way of handling the limit (e.g.,
hostapd rejecting IEEE 802.11 authentication without manual
configuration of the limit) or to figure out what type of use cases can
be executed with multiple devices before trying and failing.
Signed-off-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      b43504cf
    • J
      cfg80211: Allow BSS hint to be provided for connect · 1df4a510
      由 Jouni Malinen 提交于 
      This clarifies the expected driver behavior on the older
NL80211_ATTR_MAC and NL80211_ATTR_WIPHY_FREQ attributes and adds a new
set of similar attributes with _HINT postfix to enable use of a
recommendation of the initial BSS to choose. This can be helpful for
some drivers that can avoid an additional full scan on connection
request if the information is provided to them (user space tools like
wpa_supplicant already has that information available based on earlier
scans).

In addition, this can be used to get more expected behavior for cases
where a specific BSS should be picked first based on operations like
Interworking network selection or WPS. These cases were already easily
addressed with drivers that leave BSS selection to user space, but there
was no convenient way to do this with drivers that take care of BSS
selection internally without using the NL80211_ATTR_MAC which is not
really desired since it is needed for other purposes to force the
association to remain with the same BSS.
Signed-off-by: NJouni Malinen <j@w1.fi>
[add const, fix policy]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      1df4a510
    • L
      mac80211: only set CSA beacon when at least one beacon must be transmitted · 66e01cf9
      由 Luciano Coelho 提交于 
      A beacon should never have a Channel Switch Announcement information
element with a count of 0, because a count of 1 means switch just
before the next beacon.  So, if a count of 0 was valid in a beacon, it
would have been transmitted in the next channel already, which is
useless.  A CSA count equal to zero is only meaningful in action
frames or probe_responses.

Fix the ieee80211_csa_is_complete() and ieee80211_update_csa()
functions accordingly.

With a CSA count of 0, we won't transmit any CSA beacons, because the
switch will happen before the next TBTT.  To avoid extra work and
potential confusion in the drivers, complete the CSA immediately,
instead of waiting for the driver to call ieee80211_csa_finish().

To keep things simpler, we also switch immediately when the CSA count
is 1, while in theory we should delay the switch until just before the
next TBTT.

Additionally, move the ieee80211_csa_finish() function to cfg.c,
where it makes more sense.
Tested-by: NSimon Wunderlich <sw@simonwunderlich.de>
Acked-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      66e01cf9
  11. 03 2月, 2014 1 次提交
  13. 02 2月, 2014 1 次提交