15 Dec, 2016

2 commits


29 Sep, 2015

1 commit


02 Apr, 2015

5 commits

  • This patch adds the statistical descriptor "standard deviation"
    to better describe the current properties of Minstrel and
    Minstrel-HTs success probability distribution. The standard
    deviation (SD) is calculated as exponential weighted moving
    standard deviation (EWMSD) and its current value is added as
    new column in all rc_stats (in debugfs).

    Signed-off-by: Thomas Huehn
    Acked-by: Felix Fietkau
    Signed-off-by: Johannes Berg

    Thomas Huehn
     
  • This patch adds the new statistic "maximum possible lossless
    throughput" to Minstrels and Minstrel-HTs rc_stats (in debugfs). This
    enables comprehensive comparison between current per-rate throughput
    and max. achievable per-rate throughput.

    Signed-off-by: Thomas Huehn
    Acked-by: Felix Fietkau
    Signed-off-by: Johannes Berg

    Thomas Huehn
     
  • This patch moves Minstrels and Minstrel-HTs per-rate throughput
    calculation (EWMA(thr)) into a dedicated function to be called.
    Therefore the variable "unsigned int cur_tp" within struct
    "minstrel_rate_stats" becomes obsolete. and is removed to free
    up its space.

    Signed-off-by: Thomas Huehn
    Acked-by: Felix Fietkau
    Signed-off-by: Johannes Berg

    Thomas Huehn
     
  • This patch ensures a consistent usage of variable names for type
    "minstrel_rate_stats" to be used as "mrs" and from type minstrel_rate
    as "mr" across both Minstrel & Minstrel-HT. In addition some
    variable and function names got changed to more meaningful ones.

    Signed-off-by: Thomas Huehn
    Acked-by: Felix Fietkau
    Signed-off-by: Johannes Berg

    Thomas Huehn
     
  • This patch adds a new debugfs file "rc_stats_csv" to output Minstrels
    statistics in a common csv format that is easy to parse.

    Signed-off-by: Thomas Huehn
    Signed-off-by: Stefan Venz
    Acked-by: Felix Fietkau
    [remove printing current time of day]
    Signed-off-by: Johannes Berg

    Thomas Huehn
     

01 Apr, 2015

1 commit

  • This patch restructures the rc_stats debugfs table of Minstrel in
    order to achieve better human readability. A new layout of the
    statistics and a new header is added. In addition to the old layout
    there are two new columns of information added:
    idx - representing the rate index of each rate in mac80211 which
    can be used to set specific rates as fixed rate via debugfs
    airtime - the tx-time in micro seconds that a 1200 Byte packet
    takes to be transmitted over the air at the given rate

    The old layout of rc_stats:

    rate tpt eprob *prob ret *ok(*cum) ok( cum)
    DP 1 0.9 93.5 100.0 1 0( 0) 2( 2)
    2 0.4 40.0 100.0 0 0( 0) 4( 10)
    5.5 0.0 0.0 0.0 0 0( 0) 0( 0)
    ...

    is changed into this new layout:

    best _______rate_____ __statistics__ ________last_______ ______sum-of________
    rate [name idx tx-time] [ ø(tp) ø(prob)] [prob.|retry|suc|att] [#success | #attempts]
    DP 1 0 9738 0.9 93.5 100.0 1 1 1 2 2
    2 1 4922 0.4 40.0 100.0 1 0 0 4 10
    5.5 2 1858 0.0 0.0 0.0 2 0 0 0 0
    ...

    Signed-off-by: Thomas Huehn
    Signed-off-by: Stefan Venz
    Acked-by: Felix Fietkau
    Signed-off-by: Johannes Berg

    Thomas Huehn
     

20 Oct, 2014

1 commit

  • ATM an HT rc_stats line is 106 chars.
    Times 8(MCS_GROUP_RATES)*3(SS)*2(GI)*2(BW) + CCK(4), i.e. x100, this is
    well above the current 8192 - sizeof(*ms) currently allocated.

    Fix this by squeezing the output as follows (not that we're short on
    memory but this also improves readability and range, the new format adds
    one more digit to *ok/*cum and ok/cum):

    - Before (HT) (106 ch):
    type rate throughput ewma prob this prob retry this succ/attempt success attempts
    CCK/LP 5.5M 0.0 0.0 0.0 0 0( 0) 0 0
    HT20/LGI ABCDP MCS0 0.0 0.0 0.0 1 0( 0) 0 0
    - After (75 ch):
    type rate tpt eprob *prob ret *ok(*cum) ok( cum)
    CCK/LP 5.5M 0.0 0.0 0.0 0 0( 0) 0( 0)
    HT20/LGI ABCDP MCS0 0.0 0.0 0.0 1 0( 0) 0( 0)

    - Align non-HT format Before (non-HT) (83 ch):
    rate throughput ewma prob this prob this succ/attempt success attempts
    ABCDP 6 0.0 0.0 0.0 0( 0) 0 0
    54 0.0 0.0 0.0 0( 0) 0 0
    - After (61 ch):
    rate tpt eprob *prob *ok(*cum) ok( cum)
    ABCDP 1 0.0 0.0 0.0 0( 0) 0( 0)
    54 0.0 0.0 0.0 0( 0) 0( 0)

    *This also adds dynamic checks for overflow, lowers the size of the
    non-HT request (allowing > 30 entries) and replaces the buddy-rounded
    allocations (s/sizeof(*ms) + 8192/8192).

    Signed-off-by: Karl Beldan
    Acked-by: Felix Fietkau
    Signed-off-by: Johannes Berg

    Karl Beldan
     

11 Sep, 2014

1 commit


17 Apr, 2013

1 commit

  • This changes the minstrel stats ouput from:

    rate throughput ewma prob this prob this succ/attempt success attempts
    BCD 6 0.0 0.0 0.0 0( 0) 0 0

    to:

    rate throughput ewma prob this prob this succ/attempt success attempts
    BCD 6 0.0 0.0 0.0 0( 0) 0 0

    Signed-off-by: Karl Beldan
    Acked-by: Felix Fietkau
    Signed-off-by: Johannes Berg

    Karl Beldan
     

06 Mar, 2013

2 commits

  • This patch improves the way minstrel sorts rates according to throughput
    and success probability. 3 FOR-loops across the entire rate set in function
    minstrel_update_stats() which where used to determine the fastest, second
    fastest and most robust rate are reduced to 1 FOR-loop.

    The sorted list of rates according throughput is extended to the best four
    rates as we need them in upcoming joint rate and power control. The sorting
    is done via the new function minstrel_sort_best_tp_rates().

    The most robust rate selection is aligned with minstrel_ht's approach.
    Once any success probability is above 95% the one with the highest
    throughput is chosen as most robust rate. If success probabilities of all
    rates are below 95%, the rate with the highest succ. prob. is elected as
    most robust one

    Acked-by: Felix Fietkau
    Signed-off-by: Thomas Huehn
    Signed-off-by: Johannes Berg

    Thomas Huehn
     
  • Both minstrel versions use individual ways to scale up integer values
    to perform calculations. Merge minstrel_ht's scaling macros into
    minstrels header file and use them in both minstrel versions.

    Acked-by: Felix Fietkau
    Signed-off-by: Thomas Huehn
    Signed-off-by: Johannes Berg

    Thomas Huehn
     

01 Nov, 2011

1 commit


15 Oct, 2010

1 commit

  • All file_operations should get a .llseek operation so we can make
    nonseekable_open the default for future file operations without a
    .llseek pointer.

    The three cases that we can automatically detect are no_llseek, seq_lseek
    and default_llseek. For cases where we can we can automatically prove that
    the file offset is always ignored, we use noop_llseek, which maintains
    the current behavior of not returning an error from a seek.

    New drivers should normally not use noop_llseek but instead use no_llseek
    and call nonseekable_open at open time. Existing drivers can be converted
    to do the same when the maintainer knows for certain that no user code
    relies on calling seek on the device file.

    The generated code is often incorrectly indented and right now contains
    comments that clarify for each added line why a specific variant was
    chosen. In the version that gets submitted upstream, the comments will
    be gone and I will manually fix the indentation, because there does not
    seem to be a way to do that using coccinelle.

    Some amount of new code is currently sitting in linux-next that should get
    the same modifications, which I will do at the end of the merge window.

    Many thanks to Julia Lawall for helping me learn to write a semantic
    patch that does all this.

    ===== begin semantic patch =====
    // This adds an llseek= method to all file operations,
    // as a preparation for making no_llseek the default.
    //
    // The rules are
    // - use no_llseek explicitly if we do nonseekable_open
    // - use seq_lseek for sequential files
    // - use default_llseek if we know we access f_pos
    // - use noop_llseek if we know we don't access f_pos,
    // but we still want to allow users to call lseek
    //
    @ open1 exists @
    identifier nested_open;
    @@
    nested_open(...)
    {

    }

    @ open exists@
    identifier open_f;
    identifier i, f;
    identifier open1.nested_open;
    @@
    int open_f(struct inode *i, struct file *f)
    {

    }

    @ read disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {

    }

    @ read_no_fpos disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ write @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {

    }

    @ write_no_fpos @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ fops0 @
    identifier fops;
    @@
    struct file_operations fops = {
    ...
    };

    @ has_llseek depends on fops0 @
    identifier fops0.fops;
    identifier llseek_f;
    @@
    struct file_operations fops = {
    ...
    .llseek = llseek_f,
    ...
    };

    @ has_read depends on fops0 @
    identifier fops0.fops;
    identifier read_f;
    @@
    struct file_operations fops = {
    ...
    .read = read_f,
    ...
    };

    @ has_write depends on fops0 @
    identifier fops0.fops;
    identifier write_f;
    @@
    struct file_operations fops = {
    ...
    .write = write_f,
    ...
    };

    @ has_open depends on fops0 @
    identifier fops0.fops;
    identifier open_f;
    @@
    struct file_operations fops = {
    ...
    .open = open_f,
    ...
    };

    // use no_llseek if we call nonseekable_open
    ////////////////////////////////////////////
    @ nonseekable1 depends on !has_llseek && has_open @
    identifier fops0.fops;
    identifier nso ~= "nonseekable_open";
    @@
    struct file_operations fops = {
    ... .open = nso, ...
    +.llseek = no_llseek, /* nonseekable */
    };

    @ nonseekable2 depends on !has_llseek @
    identifier fops0.fops;
    identifier open.open_f;
    @@
    struct file_operations fops = {
    ... .open = open_f, ...
    +.llseek = no_llseek, /* open uses nonseekable */
    };

    // use seq_lseek for sequential files
    /////////////////////////////////////
    @ seq depends on !has_llseek @
    identifier fops0.fops;
    identifier sr ~= "seq_read";
    @@
    struct file_operations fops = {
    ... .read = sr, ...
    +.llseek = seq_lseek, /* we have seq_read */
    };

    // use default_llseek if there is a readdir
    ///////////////////////////////////////////
    @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier readdir_e;
    @@
    // any other fop is used that changes pos
    struct file_operations fops = {
    ... .readdir = readdir_e, ...
    +.llseek = default_llseek, /* readdir is present */
    };

    // use default_llseek if at least one of read/write touches f_pos
    /////////////////////////////////////////////////////////////////
    @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read.read_f;
    @@
    // read fops use offset
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = default_llseek, /* read accesses f_pos */
    };

    @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ... .write = write_f, ...
    + .llseek = default_llseek, /* write accesses f_pos */
    };

    // Use noop_llseek if neither read nor write accesses f_pos
    ///////////////////////////////////////////////////////////

    @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    identifier write_no_fpos.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ...
    .write = write_f,
    .read = read_f,
    ...
    +.llseek = noop_llseek, /* read and write both use no f_pos */
    };

    @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write_no_fpos.write_f;
    @@
    struct file_operations fops = {
    ... .write = write_f, ...
    +.llseek = noop_llseek, /* write uses no f_pos */
    };

    @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    @@
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = noop_llseek, /* read uses no f_pos */
    };

    @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    @@
    struct file_operations fops = {
    ...
    +.llseek = noop_llseek, /* no read or write fn */
    };
    ===== End semantic patch =====

    Signed-off-by: Arnd Bergmann
    Cc: Julia Lawall
    Cc: Christoph Hellwig

    Arnd Bergmann
     

12 Apr, 2010

1 commit


30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

11 Mar, 2010

2 commits


02 Sep, 2009

1 commit


29 Aug, 2009

1 commit


28 Oct, 2008

1 commit


07 Oct, 2008

1 commit