1. 27 9月, 2012 2 次提交
  2. 29 2月, 2012 1 次提交
  3. 24 2月, 2012 1 次提交
  4. 20 2月, 2012 2 次提交
    • D
      Replace the fd_sets in struct fdtable with an array of unsigned longs · 1fd36adc
      David Howells 提交于
      Replace the fd_sets in struct fdtable with an array of unsigned longs and then
      use the standard non-atomic bit operations rather than the FD_* macros.
      
      This:
      
       (1) Removes the abuses of struct fd_set:
      
           (a) Since we don't want to allocate a full fd_set the vast majority of the
           	 time, we actually, in effect, just allocate a just-big-enough array of
           	 unsigned longs and cast it to an fd_set type - so why bother with the
           	 fd_set at all?
      
           (b) Some places outside of the core fdtable handling code (such as
           	 SELinux) want to look inside the array of unsigned longs hidden inside
           	 the fd_set struct for more efficient iteration over the entire set.
      
       (2) Eliminates the use of FD_*() macros in the kernel completely.
      
       (3) Permits the __FD_*() macros to be deleted entirely where not exposed to
           userspace.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Link: http://lkml.kernel.org/r/20120216174954.23314.48147.stgit@warthog.procyon.org.ukSigned-off-by: NH. Peter Anvin <hpa@zytor.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      1fd36adc
    • D
      Wrap accesses to the fd_sets in struct fdtable · 1dce27c5
      David Howells 提交于
      Wrap accesses to the fd_sets in struct fdtable (for recording open files and
      close-on-exec flags) so that we can move away from using fd_sets since we
      abuse the fd_set structs by not allocating the full-sized structure under
      normal circumstances and by non-core code looking at the internals of the
      fd_sets.
      
      The first abuse means that use of FD_ZERO() on these fd_sets is not permitted,
      since that cannot be told about their abnormal lengths.
      
      This introduces six wrapper functions for setting, clearing and testing
      close-on-exec flags and fd-is-open flags:
      
      	void __set_close_on_exec(int fd, struct fdtable *fdt);
      	void __clear_close_on_exec(int fd, struct fdtable *fdt);
      	bool close_on_exec(int fd, const struct fdtable *fdt);
      	void __set_open_fd(int fd, struct fdtable *fdt);
      	void __clear_open_fd(int fd, struct fdtable *fdt);
      	bool fd_is_open(int fd, const struct fdtable *fdt);
      
      Note that I've prepended '__' to the names of the set/clear functions because
      they require the caller to hold a lock to use them.
      
      Note also that I haven't added wrappers for looking behind the scenes at the
      the array.  Possibly that should exist too.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Link: http://lkml.kernel.org/r/20120216174942.23314.1364.stgit@warthog.procyon.org.ukSigned-off-by: NH. Peter Anvin <hpa@zytor.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      1dce27c5
  5. 29 4月, 2011 1 次提交
  6. 11 8月, 2010 1 次提交
    • C
      vfs: use kmalloc() to allocate fdmem if possible · a892e2d7
      Changli Gao 提交于
      Use kmalloc() to allocate fdmem if possible.
      
      vmalloc() is used as a fallback solution for fdmem allocation.  A new
      helper function __free_fdtable() is introduced to reduce the lines of
      code.
      
      A potential bug, vfree() a memory allocated by kmalloc(), is fixed.
      
      [akpm@linux-foundation.org: use __GFP_NOWARN, uninline alloc_fdmem() and free_fdmem()]
      Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Alexey Dobriyan <adobriyan@gmail.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a892e2d7
  7. 15 6月, 2010 1 次提交
  8. 07 3月, 2010 1 次提交
  9. 25 2月, 2010 1 次提交
    • P
      vfs: Apply lockdep-based checking to rcu_dereference() uses · 7dc52157
      Paul E. McKenney 提交于
      Add lockdep-ified RCU primitives to alloc_fd(), files_fdtable()
      and fcheck_files().
      
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: laijs@cn.fujitsu.com
      Cc: dipankar@in.ibm.com
      Cc: mathieu.desnoyers@polymtl.ca
      Cc: josh@joshtriplett.org
      Cc: dvhltc@us.ibm.com
      Cc: niv@us.ibm.com
      Cc: peterz@infradead.org
      Cc: rostedt@goodmis.org
      Cc: Valdis.Kletnieks@vt.edu
      Cc: dhowells@redhat.com
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      LKML-Reference: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      7dc52157
  10. 12 10月, 2009 1 次提交
  11. 01 8月, 2008 1 次提交
  12. 27 7月, 2008 1 次提交
    • A
      [PATCH] fix RLIM_NOFILE handling · 4e1e018e
      Al Viro 提交于
      * dup2() should return -EBADF on exceeded sysctl_nr_open
      * dup() should *not* return -EINVAL even if you have rlimit set to 0;
        it should get -EMFILE instead.
      
      Check for orig_start exceeding rlimit taken to sys_fcntl().
      Failing expand_files() in dup{2,3}() now gets -EMFILE remapped to -EBADF.
      Consequently, remaining checks for rlimit are taken to expand_files().
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      4e1e018e
  13. 17 5月, 2008 6 次提交
  14. 02 5月, 2008 2 次提交
  15. 07 2月, 2008 1 次提交
    • E
      get rid of NR_OPEN and introduce a sysctl_nr_open · 9cfe015a
      Eric Dumazet 提交于
      NR_OPEN (historically set to 1024*1024) actually forbids processes to open
      more than 1024*1024 handles.
      
      Unfortunatly some production servers hit the not so 'ridiculously high
      value' of 1024*1024 file descriptors per process.
      
      Changing NR_OPEN is not considered safe because of vmalloc space potential
      exhaust.
      
      This patch introduces a new sysctl (/proc/sys/fs/nr_open) wich defaults to
      1024*1024, so that admins can decide to change this limit if their workload
      needs it.
      
      [akpm@linux-foundation.org: export it for sparc64]
      Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9cfe015a
  16. 23 12月, 2006 1 次提交
  17. 11 12月, 2006 3 次提交
    • V
      [PATCH] fdtable: Implement new pagesize-based fdtable allocator · 5466b456
      Vadim Lobanov 提交于
      This patch provides an improved fdtable allocation scheme, useful for
      expanding fdtable file descriptor entries.  The main focus is on the fdarray,
      as its memory usage grows 128 times faster than that of an fdset.
      
      The allocation algorithm sizes the fdarray in such a way that its memory usage
      increases in easy page-sized chunks. The overall algorithm expands the allowed
      size in powers of two, in order to amortize the cost of invoking vmalloc() for
      larger allocation sizes. Namely, the following sizes for the fdarray are
      considered, and the smallest that accommodates the requested fd count is
      chosen:
      
          pagesize / 4
          pagesize / 2
          pagesize      <- memory allocator switch point
          pagesize * 2
          pagesize * 4
          ...etc...
      
      Unlike the current implementation, this allocation scheme does not require a
      loop to compute the optimal fdarray size, and can be done in efficient
      straightline code.
      
      Furthermore, since the fdarray overflows the pagesize boundary long before any
      of the fdsets do, it makes sense to optimize run-time by allocating both
      fdsets in a single swoop.  Even together, they will still be, by far, smaller
      than the fdarray.  The fdtable->open_fds is now used as the anchor for the
      fdset memory allocation.
      Signed-off-by: NVadim Lobanov <vlobanov@speakeasy.net>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Dipankar Sarma <dipankar@in.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      5466b456
    • V
      [PATCH] fdtable: Remove the free_files field · 4fd45812
      Vadim Lobanov 提交于
      An fdtable can either be embedded inside a files_struct or standalone (after
      being expanded).  When an fdtable is being discarded after all RCU references
      to it have expired, we must either free it directly, in the standalone case,
      or free the files_struct it is contained within, in the embedded case.
      
      Currently the free_files field controls this behavior, but we can get rid of
      it entirely, as all the necessary information is already recorded.  We can
      distinguish embedded and standalone fdtables using max_fds, and if it is
      embedded we can divine the relevant files_struct using container_of().
      Signed-off-by: NVadim Lobanov <vlobanov@speakeasy.net>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Dipankar Sarma <dipankar@in.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      4fd45812
    • V
      [PATCH] fdtable: Make fdarray and fdsets equal in size · bbea9f69
      Vadim Lobanov 提交于
      Currently, each fdtable supports three dynamically-sized arrays of data: the
      fdarray and two fdsets.  The code allows the number of fds supported by the
      fdarray (fdtable->max_fds) to differ from the number of fds supported by each
      of the fdsets (fdtable->max_fdset).
      
      In practice, it is wasteful for these two sizes to differ: whenever we hit a
      limit on the smaller-capacity structure, we will reallocate the entire fdtable
      and all the dynamic arrays within it, so any delta in the memory used by the
      larger-capacity structure will never be touched at all.
      
      Rather than hogging this excess, we shouldn't even allocate it in the first
      place, and keep the capacities of the fdarray and the fdsets equal.  This
      patch removes fdtable->max_fdset.  As an added bonus, most of the supporting
      code becomes simpler.
      Signed-off-by: NVadim Lobanov <vlobanov@speakeasy.net>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Dipankar Sarma <dipankar@in.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      bbea9f69
  18. 08 12月, 2006 1 次提交
  19. 22 11月, 2006 1 次提交
    • D
      WorkStruct: Pass the work_struct pointer instead of context data · 65f27f38
      David Howells 提交于
      Pass the work_struct pointer to the work function rather than context data.
      The work function can use container_of() to work out the data.
      
      For the cases where the container of the work_struct may go away the moment the
      pending bit is cleared, it is made possible to defer the release of the
      structure by deferring the clearing of the pending bit.
      
      To make this work, an extra flag is introduced into the management side of the
      work_struct.  This governs auto-release of the structure upon execution.
      
      Ordinarily, the work queue executor would release the work_struct for further
      scheduling or deallocation by clearing the pending bit prior to jumping to the
      work function.  This means that, unless the driver makes some guarantee itself
      that the work_struct won't go away, the work function may not access anything
      else in the work_struct or its container lest they be deallocated..  This is a
      problem if the auxiliary data is taken away (as done by the last patch).
      
      However, if the pending bit is *not* cleared before jumping to the work
      function, then the work function *may* access the work_struct and its container
      with no problems.  But then the work function must itself release the
      work_struct by calling work_release().
      
      In most cases, automatic release is fine, so this is the default.  Special
      initiators exist for the non-auto-release case (ending in _NAR).
      Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      65f27f38
  20. 30 9月, 2006 2 次提交
  21. 27 9月, 2006 1 次提交
  22. 13 7月, 2006 2 次提交
  23. 11 7月, 2006 1 次提交
  24. 29 3月, 2006 1 次提交
  25. 23 3月, 2006 1 次提交
    • E
      [PATCH] Shrinks sizeof(files_struct) and better layout · 0c9e63fd
      Eric Dumazet 提交于
      1) Reduce the size of (struct fdtable) to exactly 64 bytes on 32bits
         platforms, lowering kmalloc() allocated space by 50%.
      
      2) Reduce the size of (files_struct), using a special 32 bits (or
         64bits) embedded_fd_set, instead of a 1024 bits fd_set for the
         close_on_exec_init and open_fds_init fields.  This save some ram (248
         bytes per task) as most tasks dont open more than 32 files.  D-Cache
         footprint for such tasks is also reduced to the minimum.
      
      3) Reduce size of allocated fdset.  Currently two full pages are
         allocated, that is 32768 bits on x86 for example, and way too much.  The
         minimum is now L1_CACHE_BYTES.
      
      UP and SMP should benefit from this patch, because most tasks will touch
      only one cache line when open()/close() stdin/stdout/stderr (0/1/2),
      (next_fd, close_on_exec_init, open_fds_init, fd_array[0 ..  2] being in the
      same cache line)
      Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      0c9e63fd
  26. 06 2月, 2006 1 次提交
  27. 15 9月, 2005 1 次提交
  28. 10 9月, 2005 1 次提交
    • D
      [PATCH] files: files struct with RCU · ab2af1f5
      Dipankar Sarma 提交于
      Patch to eliminate struct files_struct.file_lock spinlock on the reader side
      and use rcu refcounting rcuref_xxx api for the f_count refcounter.  The
      updates to the fdtable are done by allocating a new fdtable structure and
      setting files->fdt to point to the new structure.  The fdtable structure is
      protected by RCU thereby allowing lock-free lookup.  For fd arrays/sets that
      are vmalloced, we use keventd to free them since RCU callbacks can't sleep.  A
      global list of fdtable to be freed is not scalable, so we use a per-cpu list.
      If keventd is already handling the current cpu's work, we use a timer to defer
      queueing of that work.
      
      Since the last publication, this patch has been re-written to avoid using
      explicit memory barriers and use rcu_assign_pointer(), rcu_dereference()
      premitives instead.  This required that the fd information is kept in a
      separate structure (fdtable) and updated atomically.
      Signed-off-by: NDipankar Sarma <dipankar@in.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      ab2af1f5