1. 11 Oct, 2012 1 commit
    • Simon Derr's avatar
      9P: Fix race between p9_write_work() and p9_fd_request() · 759f4298
      Simon Derr authored
      Race scenario:
      
      thread A			thread B
      
      p9_write_work()                p9_fd_request()
      
      if (list_empty
        (&m->unsent_req_list))
        ...
      
                                     spin_lock(&client->lock);
                                     req->status = REQ_STATUS_UNSENT;
                                     list_add_tail(..., &m->unsent_req_list);
                                     spin_unlock(&client->lock);
                                     ....
                                     if (n & POLLOUT &&
                                     !test_and_set_bit(Wworksched, &m->wsched)
                                     schedule_work(&m->wq);
                                     --> not done because Wworksched is set
      
        clear_bit(Wworksched, &m->wsched);
        return;
      
      --> nobody will take care of sending the new request.
      
      This is not very likely to happen though, because p9_write_work()
      being called with an empty unsent_req_list is not frequent.
      But this also means that taking the lock earlier will not be costly.
      Signed-off-by: default avatarSimon Derr <simon.derr@bull.net>
      Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
      759f4298
  2. 27 Sep, 2012 1 commit
  3. 17 Sep, 2012 3 commits
  4. 20 Aug, 2012 1 commit
    • Tejun Heo's avatar
      workqueue: deprecate flush[_delayed]_work_sync() · 43829731
      Tejun Heo authored
      flush[_delayed]_work_sync() are now spurious.  Mark them deprecated
      and convert all users to flush[_delayed]_work().
      
      If you're cc'd and wondering what's going on: Now all workqueues are
      non-reentrant and the regular flushes guarantee that the work item is
      not pending or running on any CPU on return, so there's no reason to
      use the sync flushes at all and they're going away.
      
      This patch doesn't make any functional difference.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Ian Campbell <ian.campbell@citrix.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Mattia Dongili <malattia@linux.it>
      Cc: Kent Yoder <key@linux.vnet.ibm.com>
      Cc: David Airlie <airlied@linux.ie>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Karsten Keil <isdn@linux-pingi.de>
      Cc: Bryan Wu <bryan.wu@canonical.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Alasdair Kergon <agk@redhat.com>
      Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
      Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: linux-wireless@vger.kernel.org
      Cc: Anton Vorontsov <cbou@mail.ru>
      Cc: Sangbeom Kim <sbkim73@samsung.com>
      Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Eric Van Hensbergen <ericvh@gmail.com>
      Cc: Takashi Iwai <tiwai@suse.de>
      Cc: Steven Whitehouse <swhiteho@redhat.com>
      Cc: Petr Vandrovec <petr@vandrovec.name>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Avi Kivity <avi@redhat.com> 
      43829731
  5. 15 Apr, 2012 1 commit
  6. 05 Jan, 2012 1 commit
    • Joe Perches's avatar
      9p: Reduce object size with CONFIG_NET_9P_DEBUG · 5d385153
      Joe Perches authored
      Reduce object size by deduplicating formats.
      
      Use vsprintf extension %pV.
      Rename P9_DPRINTK uses to p9_debug, align arguments.
      Add function for _p9_debug and macro to add __func__.
      Add missing "\n"s to p9_debug uses.
      Remove embedded function names as p9_debug adds it.
      Remove P9_EPRINTK macro and convert use to pr_<level>.
      Add and use pr_fmt and pr_<level>.
      
      $ size fs/9p/built-in.o*
         text	   data	    bss	    dec	    hex	filename
        62133	    984	  16000	  79117	  1350d	fs/9p/built-in.o.new
        67342	    984	  16928	  85254	  14d06	fs/9p/built-in.o.old
      $ size net/9p/built-in.o*
         text	   data	    bss	    dec	    hex	filename
        88792	   4148	  22024	 114964	  1c114	net/9p/built-in.o.new
        94072	   4148	  23232	 121452	  1da6c	net/9p/built-in.o.old
      Signed-off-by: default avatarJoe Perches <joe@perches.com>
      Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
      5d385153
  7. 25 May, 2011 1 commit
  8. 19 May, 2011 1 commit
  9. 22 Mar, 2011 1 commit
    • Aneesh Kumar K.V's avatar
      net/9p: Convert the in the 9p rpc call path to GFP_NOFS · eeff66ef
      Aneesh Kumar K.V authored
      Without this we can cause reclaim allocation in writepage.
      
      [ 3433.448430] =================================
      [ 3433.449117] [ INFO: inconsistent lock state ]
      [ 3433.449117] 2.6.38-rc5+ #84
      [ 3433.449117] ---------------------------------
      [ 3433.449117] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-R} usage.
      [ 3433.449117] kswapd0/505 [HC0[0]:SC0[0]:HE1:SE1] takes:
      [ 3433.449117]  (iprune_sem){+++++-}, at: [<ffffffff810ebbab>] shrink_icache_memory+0x45/0x2b1
      [ 3433.449117] {RECLAIM_FS-ON-W} state was registered at:
      [ 3433.449117]   [<ffffffff8107fe5f>] mark_held_locks+0x52/0x70
      [ 3433.449117]   [<ffffffff8107ff02>] lockdep_trace_alloc+0x85/0x9f
      [ 3433.449117]   [<ffffffff810d353d>] slab_pre_alloc_hook+0x18/0x3c
      [ 3433.449117]   [<ffffffff810d3fd5>] kmem_cache_alloc+0x23/0xa2
      [ 3433.449117]   [<ffffffff8127be77>] idr_pre_get+0x2d/0x6f
      [ 3433.449117]   [<ffffffff815434eb>] p9_idpool_get+0x30/0xae
      [ 3433.449117]   [<ffffffff81540123>] p9_client_rpc+0xd7/0x9b0
      [ 3433.449117]   [<ffffffff815427b0>] p9_client_clunk+0x88/0xdb
      [ 3433.449117]   [<ffffffff811d56e5>] v9fs_evict_inode+0x3c/0x48
      [ 3433.449117]   [<ffffffff810eb511>] evict+0x1f/0x87
      [ 3433.449117]   [<ffffffff810eb5c0>] dispose_list+0x47/0xe3
      [ 3433.449117]   [<ffffffff810eb8da>] evict_inodes+0x138/0x14f
      [ 3433.449117]   [<ffffffff810d90e2>] generic_shutdown_super+0x57/0xe8
      [ 3433.449117]   [<ffffffff810d91e8>] kill_anon_super+0x11/0x50
      [ 3433.449117]   [<ffffffff811d4951>] v9fs_kill_super+0x49/0xab
      [ 3433.449117]   [<ffffffff810d926e>] deactivate_locked_super+0x21/0x46
      [ 3433.449117]   [<ffffffff810d9e84>] deactivate_super+0x40/0x44
      [ 3433.449117]   [<ffffffff810ef848>] mntput_no_expire+0x100/0x109
      [ 3433.449117]   [<ffffffff810f0aeb>] sys_umount+0x2f1/0x31c
      [ 3433.449117]   [<ffffffff8102c87b>] system_call_fastpath+0x16/0x1b
      [ 3433.449117] irq event stamp: 192941
      [ 3433.449117] hardirqs last  enabled at (192941): [<ffffffff81568dcf>] _raw_spin_unlock_irq+0x2b/0x30
      [ 3433.449117] hardirqs last disabled at (192940): [<ffffffff810b5f97>] shrink_inactive_list+0x290/0x2f5
      [ 3433.449117] softirqs last  enabled at (188470): [<ffffffff8105fd65>] __do_softirq+0x133/0x152
      [ 3433.449117] softirqs last disabled at (188455): [<ffffffff8102d7cc>] call_softirq+0x1c/0x28
      [ 3433.449117]
      [ 3433.449117] other info that might help us debug this:
      [ 3433.449117] 1 lock held by kswapd0/505:
      [ 3433.449117]  #0:  (shrinker_rwsem){++++..}, at: [<ffffffff810b52e2>] shrink_slab+0x38/0x15f
      [ 3433.449117]
      [ 3433.449117] stack backtrace:
      [ 3433.449117] Pid: 505, comm: kswapd0 Not tainted 2.6.38-rc5+ #84
      [ 3433.449117] Call Trace:
      [ 3433.449117]  [<ffffffff8107fbce>] ? valid_state+0x17e/0x191
      [ 3433.449117]  [<ffffffff81036896>] ? save_stack_trace+0x28/0x45
      [ 3433.449117]  [<ffffffff81080426>] ? check_usage_forwards+0x0/0x87
      [ 3433.449117]  [<ffffffff8107fcf4>] ? mark_lock+0x113/0x22c
      [ 3433.449117]  [<ffffffff8108105f>] ? __lock_acquire+0x37a/0xcf7
      [ 3433.449117]  [<ffffffff8107fc0e>] ? mark_lock+0x2d/0x22c
      [ 3433.449117]  [<ffffffff81081077>] ? __lock_acquire+0x392/0xcf7
      [ 3433.449117]  [<ffffffff810b14d2>] ? determine_dirtyable_memory+0x15/0x28
      [ 3433.449117]  [<ffffffff81081a33>] ? lock_acquire+0x57/0x6d
      [ 3433.449117]  [<ffffffff810ebbab>] ? shrink_icache_memory+0x45/0x2b1
      [ 3433.449117]  [<ffffffff81567d85>] ? down_read+0x47/0x5c
      [ 3433.449117]  [<ffffffff810ebbab>] ? shrink_icache_memory+0x45/0x2b1
      [ 3433.449117]  [<ffffffff810ebbab>] ? shrink_icache_memory+0x45/0x2b1
      [ 3433.449117]  [<ffffffff810b5385>] ? shrink_slab+0xdb/0x15f
      [ 3433.449117]  [<ffffffff810b69bc>] ? kswapd+0x574/0x96a
      [ 3433.449117]  [<ffffffff810b6448>] ? kswapd+0x0/0x96a
      [ 3433.449117]  [<ffffffff810714e2>] ? kthread+0x7d/0x85
      [ 3433.449117]  [<ffffffff8102d6d4>] ? kernel_thread_helper+0x4/0x10
      [ 3433.449117]  [<ffffffff81569200>] ? restore_args+0x0/0x30
      [ 3433.449117]  [<ffffffff81071465>] ? kthread+0x0/0x85
      [ 3433.449117]  [<ffffffff8102d6d0>] ? kernel_thread_helper+0x0/0x10
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarVenkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
      Signed-off-by: default avatarEric Van Hensbergen <ericvh@gmail.com>
      eeff66ef
  10. 01 Feb, 2011 2 commits
    • Tejun Heo's avatar
      net/9p: replace p9_poll_task with a work · aa70c585
      Tejun Heo authored
      Now that cmwq can handle high concurrency, it's more efficient to use
      work than a dedicated kthread.  Convert p9_poll_proc() to a work
      function for p9_poll_work and make p9_pollwake() schedule it on each
      poll event.  The work is sync flushed on module exit.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Eric Van Hensbergen <ericvh@gmail.com>
      Cc: Ron Minnich <rminnich@sandia.gov>
      Cc: Latchesar Ionkov <lucho@ionkov.net>
      Cc: v9fs-developer@lists.sourceforge.net
      aa70c585
    • Tejun Heo's avatar
      net/9p: use system_wq instead of p9_mux_wq · 61edeeed
      Tejun Heo authored
      With cmwq, there's no reason to use a dedicated workqueue in trans_fd.
      Drop p9_mux_wq and use system_wq instead.  The used work items are
      already sync canceled in p9_conn_destroy() and doesn't require further
      synchronization.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Eric Van Hensbergen <ericvh@gmail.com>
      Cc: Ron Minnich <rminnich@sandia.gov>
      Cc: Latchesar Ionkov <lucho@ionkov.net>
      Cc: v9fs-developer@lists.sourceforge.net
      61edeeed
  11. 07 Sep, 2010 1 commit
  12. 02 Aug, 2010 1 commit
  13. 13 Jul, 2010 1 commit
  14. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit 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: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  15. 08 Feb, 2010 1 commit
  16. 16 Dec, 2009 1 commit
    • Al Viro's avatar
      9p connect fixes · 6b18662e
      Al Viro authored
      * if we fail in p9_conn_create(), we shouldn't leak references to struct file.
        Logics in ->close() doesn't help - ->trans is already gone by the time it's
        called.
      * sock_create_kern() can fail.
      * use of sock_map_fd() is all fscked up; I'd fixed most of that, but the
        rest will have to wait for a bit more work in net/socket.c (we still are
        violating the basic rule of working with descriptor table: "once the reference
        is installed there, don't rely on finding it there again").
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      6b18662e
  17. 30 Nov, 2009 1 commit
  18. 17 Aug, 2009 1 commit
  19. 02 Jul, 2009 1 commit
  20. 05 Apr, 2009 1 commit
  21. 27 Feb, 2009 1 commit
  22. 22 Oct, 2008 1 commit
  23. 17 Oct, 2008 15 commits