26 Sep, 2011

1 commit

  • Following reports on the list, it looks like the 3e-9xxx driver will leak dma
    mappings every time we get a transient queueing error back from the card.
    This is because it maps the sg list in the routine that sends the command, but
    doesn't unmap again in the transient failure path (even though the command is
    sent back to the block layer). Fix by unmapping before returning the status.

    Reported-by: Chris Boot
    Tested-by: Chris Boot
    Acked-by: Adam Radford
    Cc: stable@kernel.org
    Signed-off-by: James Bottomley

    James Bottomley
     

17 Nov, 2010

1 commit

  • Move the mid-layer's ->queuecommand() invocation from being locked
    with the host lock to being unlocked to facilitate speeding up the
    critical path for drivers who don't need this lock taken anyway.

    The patch below presents a simple SCSI host lock push-down as an
    equivalent transformation. No locking or other behavior should change
    with this patch. All existing bugs and locking orders are preserved.

    Additionally, add one parameter to queuecommand,
    struct Scsi_Host *
    and remove one parameter from queuecommand,
    void (*done)(struct scsi_cmnd *)

    Scsi_Host* is a convenient pointer that most host drivers need anyway,
    and 'done' is redundant to struct scsi_cmnd->scsi_done.

    Minimal code disturbance was attempted with this change. Most drivers
    needed only two one-line modifications for their host lock push-down.

    Signed-off-by: Jeff Garzik
    Acked-by: James Bottomley
    Signed-off-by: Linus Torvalds

    Jeff Garzik
     

23 Oct, 2010

1 commit

  • * 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
    vfs: make no_llseek the default
    vfs: don't use BKL in default_llseek
    llseek: automatically add .llseek fop
    libfs: use generic_file_llseek for simple_attr
    mac80211: disallow seeks in minstrel debug code
    lirc: make chardev nonseekable
    viotape: use noop_llseek
    raw: use explicit llseek file operations
    ibmasmfs: use generic_file_llseek
    spufs: use llseek in all file operations
    arm/omap: use generic_file_llseek in iommu_debug
    lkdtm: use generic_file_llseek in debugfs
    net/wireless: use generic_file_llseek in debugfs
    drm: use noop_llseek

    Linus Torvalds
     

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
     

16 Sep, 2010

1 commit

  • All these files use the big kernel lock in a trivial
    way to serialize their private file operations,
    typically resulting from an earlier semi-automatic
    pushdown from VFS.

    None of these drivers appears to want to lock against
    other code, and they all use the BKL as the top-level
    lock in their file operations, meaning that there
    is no lock-order inversion problem.

    Consequently, we can remove the BKL completely,
    replacing it with a per-file mutex in every case.
    Using a scripted approach means we can avoid
    typos.

    file=$1
    name=$2
    if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
    sed -i '/include.*/d' ${file}
    else
    sed -i 's/include.*.*$/include /g' ${file}
    fi
    sed -i ${file} \
    -e "/^#include.*linux.mutex.h/,$ {
    1,/^\(static\|int\|long\)/ {
    /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

    } }" \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[ ]*cycle_kernel_lock();/d'
    else
    sed -i -e '/include.*\/d' ${file} \
    -e '/cycle_kernel_lock()/d'
    fi

    Signed-off-by: Arnd Bergmann
    Cc: linux-scsi@vger.kernel.org
    Cc: "James E.J. Bottomley"

    Arnd Bergmann
     

24 May, 2010

1 commit

  • * 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
    uml: Pushdown the bkl from harddog_kern ioctl
    sunrpc: Pushdown the bkl from sunrpc cache ioctl
    sunrpc: Pushdown the bkl from ioctl
    autofs4: Pushdown the bkl from ioctl
    uml: Convert to unlocked_ioctls to remove implicit BKL
    ncpfs: BKL ioctl pushdown
    coda: Clean-up whitespace problems in pioctl.c
    coda: BKL ioctl pushdown
    drivers: Push down BKL into various drivers
    isdn: Push down BKL into ioctl functions
    scsi: Push down BKL into ioctl functions
    dvb: Push down BKL into ioctl functions
    smbfs: Push down BKL into ioctl function
    coda/psdev: Remove BKL from ioctl function
    um/mmapper: Remove BKL usage
    sn_hwperf: Kill BKL usage
    hfsplus: Push down BKL into ioctl function

    Linus Torvalds
     

17 May, 2010

1 commit

  • Push down the bkl into ioctl functions on the scsi layer.

    [jkacur: Forward declaration missing ';'.
    Conflicting declaraction in megaraid.h changed
    Fixed missing inodes declarations]

    Signed-off-by: Arnd Bergmann
    Signed-off-by: John Kacur
    Signed-off-by: Frederic Weisbecker

    Arnd Bergmann
     

11 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
     

13 Dec, 2009

1 commit


10 Dec, 2009

1 commit

  • * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits)
    tree-wide: fix misspelling of "definition" in comments
    reiserfs: fix misspelling of "journaled"
    doc: Fix a typo in slub.txt.
    inotify: remove superfluous return code check
    hdlc: spelling fix in find_pvc() comment
    doc: fix regulator docs cut-and-pasteism
    mtd: Fix comment in Kconfig
    doc: Fix IRQ chip docs
    tree-wide: fix assorted typos all over the place
    drivers/ata/libata-sff.c: comment spelling fixes
    fix typos/grammos in Documentation/edac.txt
    sysctl: add missing comments
    fs/debugfs/inode.c: fix comment typos
    sgivwfb: Make use of ARRAY_SIZE.
    sky2: fix sky2_link_down copy/paste comment error
    tree-wide: fix typos "couter" -> "counter"
    tree-wide: fix typos "offest" -> "offset"
    fix kerneldoc for set_irq_msi()
    spidev: fix double "of of" in comment
    comment typo fix: sybsystem -> subsystem
    ...

    Linus Torvalds
     

05 Dec, 2009

1 commit

  • This patch modifies scsi_host_template->change_queue_depth so that
    it takes an argument indicating why it is being called. This will be
    used so that if a LLD needs to do some extra processing when
    handling queue fulls or later ramp ups, it can do so.

    This is a simple port of the drivers setting a change_queue_depth
    callback. In the patch I just have these LLDs adjust the queue depth
    if the user was requesting it.

    Signed-off-by: Mike Christie

    [Vasu.Dev: v2
    Also converted pmcraid_change_queue_depth and then verified
    all modules compile using "make allmodconfig" for any new build
    warnings on X86_64.

    Updated original description after combing two original
    patches from Mike to make this patch git bisectable.]
    Signed-off-by: Vasu Dev
    [jejb: fixed up 53c700]
    Signed-off-by: James Bottomley

    Mike Christie
     

09 Nov, 2009

1 commit

  • something-bility is spelled as something-blity
    so a grep for 'blit' would find these lines

    this is so trivial that I didn't split it by subsystem / copy
    additional maintainers - all changes are to comments
    The only purpose is to get fewer false positives when grepping
    around the kernel sources.

    Signed-off-by: Dirk Hohndel
    Signed-off-by: Jiri Kosina

    Dirk Hohndel
     

16 May, 2009

1 commit

  • This patch fixes the following regression the occurred during the
    scsi_dma_map()/unmap() changes:

    3w-9xxx 0001:45:00.0: DMA-API: device driver tries to free DMA memory
    it has not allocated [device address=0x0000000000000000] [size=36
    bytes]

    Signed-off-by: Adam Radford
    Signed-off-by: James Bottomley

    adam radford
     

14 Apr, 2009

1 commit

  • This is the second go through of the old DMA_nBIT_MASK macro,and there're not
    so many of them left,so I put them into one patch.I hope this is the last round.
    After this the definition of the old DMA_nBIT_MASK macro could be removed.

    Signed-off-by: Yang Hongyang
    Cc: Russell King
    Cc: Tony Lindgren
    Cc: "David S. Miller"
    Cc: James Bottomley
    Cc: Greg KH
    Cc: Takashi Iwai
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Yang Hongyang
     

07 Apr, 2009

2 commits


14 Mar, 2009

1 commit


24 Oct, 2008

1 commit


27 Jul, 2008

1 commit

  • This patch for the 3w-9xxx scsi driver applies on top of the
    BKL-pushdown changes in -git9.

    This patch does the following:

    - Increase max AENs drained to 256.
    - Add MSI support and "use_msi" module parameter.
    - Fix bug in twa_get_param() on 4GB+.
    - Use pci_resource_len() for ioremap().

    Signed-off-by: James Bottomley

    adam radford
     

15 Jul, 2008

1 commit


21 Jun, 2008

2 commits


23 May, 2008

1 commit

  • drivers/scsi/aha152x.c:3585:60: warning: Using plain integer as NULL pointer
    drivers/scsi/aha152x.c:3845:56: warning: Using plain integer as NULL pointer
    drivers/scsi/qla1280.c:2814:37: warning: Using plain integer as NULL pointer
    drivers/scsi/atp870u.c:750:47: warning: Using plain integer as NULL pointer
    drivers/scsi/3w-9xxx.c:1281:36: warning: Using plain integer as NULL pointer
    drivers/scsi/3w-9xxx.c:1293:36: warning: Using plain integer as NULL pointer
    drivers/scsi/3w-9xxx.c:1301:35: warning: Using plain integer as NULL pointer
    drivers/scsi/hptiop.c:447:10: warning: Using plain integer as NULL pointer
    drivers/scsi/hptiop.c:457:10: warning: Using plain integer as NULL pointer
    drivers/scsi/hptiop.c:479:24: warning: Using plain integer as NULL pointer
    drivers/scsi/hptiop.c:483:22: warning: Using plain integer as NULL pointer
    drivers/scsi/hptiop.c:1213:23: warning: Using plain integer as NULL pointer
    drivers/scsi/hptiop.c:1214:23: warning: Using plain integer as NULL pointer

    Signed-off-by: Harvey Harrison
    Signed-off-by: Linus Torvalds

    Harvey Harrison
     

20 Apr, 2008

1 commit


08 Apr, 2008

2 commits


31 Jan, 2008

1 commit

  • With the sg table code, every SCSI driver is now either chain capable
    or broken (or has sg_tablesize set so chaining is never activated), so
    there's no need to have a check in the host template.

    Also tidy up the code by moving the scatterlist size defines into the
    SCSI includes and permit the last entry of the scatterlist pools not
    to be a power of two.
    Signed-off-by: James Bottomley

    James Bottomley
     

12 Jan, 2008

1 commit

  • The 3ware 9500S-8 SATA RAID controller exhibits terrible write
    performance when PCI memory-write-and-invalidate is disabled. This is
    easy to demonstrate by replacing pci_try_set_mwi() in the patch below
    with pci_clear_mwi(). My benchmarks show the following:

    MWI disabled: 15 MB/s write, 330 MB/s read
    MWI enabled: 240 MB/s write, 330 MB/s read

    Most motherboards will enable MWI without the driver having to set it
    explicitly, so most people probably wouldn't encounter this problem.
    For the few motherboards that don't enable it, this patch could give a
    16x performance improvement for writing.

    This issue does not seem to affect the 9550SX controller, but the patch
    doesn't hurt it either. I haven't tested any of the other 3ware
    controllers.

    Signed-off-by: Tony Battersby
    Acked-by: adam radford
    Signed-off-by: James Bottomley

    Tony Battersby
     

23 Oct, 2007

1 commit


16 Oct, 2007

1 commit


23 Jul, 2007

1 commit

  • * master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (60 commits)
    [SCSI] libsas: make ATA functions selectable by a config option
    [SCSI] bsg: unexport sg v3 helper functions
    [SCSI] bsg: fix bsg_unregister_queue
    [SCSI] bsg: make class backlinks
    [SCSI] 3w-9xxx: add support for 9690SA
    [SCSI] bsg: fix bsg_register_queue error path
    [SCSI] ESP: Increase ESP_BUS_TIMEOUT to 275.
    [SCSI] libsas: fix scr_read/write users and update the libata documentation
    [SCSI] mpt fusion: update Kconfig help
    [SCSI] scsi_transport_sas: add destructor for bsg
    [SCSI] iscsi_tcp: buggered kmalloc()
    [SCSI] qla2xxx: Update version number to 8.02.00-k2.
    [SCSI] qla2xxx: Add ISP25XX support.
    [SCSI] qla2xxx: Use pci_try_set_mwi().
    [SCSI] qla2xxx: Use PCI-X/PCI-Express read control interfaces.
    [SCSI] qla2xxx: Re-factor isp_operations to static structures.
    [SCSI] qla2xxx: Validate mid-layer 'underflow' during check-condition handling.
    [SCSI] qla2xxx: Correct setting of 'current' and 'supported' speeds during FDMI registration.
    [SCSI] qla2xxx: Generalize iIDMA support.
    [SCSI] qla2xxx: Generalize FW-Interface-2 support.
    ...

    Linus Torvalds
     

21 Jul, 2007

1 commit


20 Jul, 2007

1 commit

  • Transform some calls to kmalloc/memset to a single kzalloc (or kcalloc).

    Here is a short excerpt of the semantic patch performing
    this transformation:

    @@
    type T2;
    expression x;
    identifier f,fld;
    expression E;
    expression E1,E2;
    expression e1,e2,e3,y;
    statement S;
    @@

    x =
    - kmalloc
    + kzalloc
    (E1,E2)
    ... when != \(x->fld=E;\|y=f(...,x,...);\|f(...,x,...);\|x=E;\|while(...) S\|for(e1;e2;e3) S\)
    - memset((T2)x,0,E1);

    @@
    expression E1,E2,E3;
    @@

    - kzalloc(E1 * E2,E3)
    + kcalloc(E1,E2,E3)

    [akpm@linux-foundation.org: get kcalloc args the right way around]
    Signed-off-by: Yoann Padioleau
    Cc: Richard Henderson
    Cc: Ivan Kokshaysky
    Acked-by: Russell King
    Cc: Bryan Wu
    Acked-by: Jiri Slaby
    Cc: Dave Airlie
    Acked-by: Roland Dreier
    Cc: Jiri Kosina
    Acked-by: Dmitry Torokhov
    Cc: Benjamin Herrenschmidt
    Acked-by: Mauro Carvalho Chehab
    Acked-by: Pierre Ossman
    Cc: Jeff Garzik
    Cc: "David S. Miller"
    Acked-by: Greg KH
    Cc: James Bottomley
    Cc: "Antonino A. Daplas"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Yoann Padioleau
     

31 May, 2007

2 commits


13 Feb, 2007

1 commit

  • Many struct file_operations in the kernel can be "const". Marking them const
    moves these to the .rodata section, which avoids false sharing with potential
    dirty data. In addition it'll catch accidental writes at compile time to
    these shared resources.

    Signed-off-by: Arjan van de Ven
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arjan van de Ven
     

09 Nov, 2006

1 commit


05 Oct, 2006

1 commit

  • Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
    of passing regs around manually through all ~1800 interrupt handlers in the
    Linux kernel.

    The regs pointer is used in few places, but it potentially costs both stack
    space and code to pass it around. On the FRV arch, removing the regs parameter
    from all the genirq function results in a 20% speed up of the IRQ exit path
    (ie: from leaving timer_interrupt() to leaving do_IRQ()).

    Where appropriate, an arch may override the generic storage facility and do
    something different with the variable. On FRV, for instance, the address is
    maintained in GR28 at all times inside the kernel as part of general exception
    handling.

    Having looked over the code, it appears that the parameter may be handed down
    through up to twenty or so layers of functions. Consider a USB character
    device attached to a USB hub, attached to a USB controller that posts its
    interrupts through a cascaded auxiliary interrupt controller. A character
    device driver may want to pass regs to the sysrq handler through the input
    layer which adds another few layers of parameter passing.

    I've build this code with allyesconfig for x86_64 and i386. I've runtested the
    main part of the code on FRV and i386, though I can't test most of the drivers.
    I've also done partial conversion for powerpc and MIPS - these at least compile
    with minimal configurations.

    This will affect all archs. Mostly the changes should be relatively easy.
    Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

    struct pt_regs *old_regs = set_irq_regs(regs);

    And put the old one back at the end:

    set_irq_regs(old_regs);

    Don't pass regs through to generic_handle_irq() or __do_IRQ().

    In timer_interrupt(), this sort of change will be necessary:

    - update_process_times(user_mode(regs));
    - profile_tick(CPU_PROFILING, regs);
    + update_process_times(user_mode(get_irq_regs()));
    + profile_tick(CPU_PROFILING);

    I'd like to move update_process_times()'s use of get_irq_regs() into itself,
    except that i386, alone of the archs, uses something other than user_mode().

    Some notes on the interrupt handling in the drivers:

    (*) input_dev() is now gone entirely. The regs pointer is no longer stored in
    the input_dev struct.

    (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
    something different depending on whether it's been supplied with a regs
    pointer or not.

    (*) Various IRQ handler function pointers have been moved to type
    irq_handler_t.

    Signed-Off-By: David Howells
    (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

    David Howells
     

27 Sep, 2006

1 commit