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  1. 14 Feb, 2008 1 commit
  3. 08 Feb, 2008 1 commit
  5. 15 Oct, 2007 2 commits
  7. 27 Jul, 2007 1 commit
  9. 10 Jul, 2007 2 commits
  11. 08 May, 2007 1 commit
    • Eric Dumazet's avatar
      VFS: delay the dentry name generation on sockets and pipes · c23fbb6b
      Eric Dumazet authored 
      1) Introduces a new method in 'struct dentry_operations'.  This method
   called d_dname() might be called from d_path() to build a pathname for
   special filesystems.  It is called without locks.

   Future patches (if we succeed in having one common dentry for all
   pipes/sockets) may need to change prototype of this method, but we now
   use : char *d_dname(struct dentry *dentry, char *buffer, int buflen);

2) Adds a dynamic_dname() helper function that eases d_dname() implementations

3) Defines d_dname method for sockets : No more sprintf() at socket
   creation.  This is delayed up to the moment someone does an access to
   /proc/pid/fd/...

4) Defines d_dname method for pipes : No more sprintf() at pipe
   creation.  This is delayed up to the moment someone does an access to
   /proc/pid/fd/...

A benchmark consisting of 1.000.000 calls to pipe()/close()/close() gives a
*nice* speedup on my Pentium(M) 1.6 Ghz :

3.090 s instead of 3.450 s
Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
Acked-by: default avatarChristoph Hellwig <hch@infradead.org>
Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c23fbb6b
  13. 18 Feb, 2007 1 commit
    • Al Viro's avatar
      [PATCH] AUDIT_FD_PAIR · db349509
      Al Viro authored 
      Provide an audit record of the descriptor pair returned by pipe() and
socketpair().  Rewritten from the original posted to linux-audit by
John D. Ramsdell <ramsdell@mitre.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      db349509
  15. 21 Dec, 2006 1 commit
  17. 13 Dec, 2006 1 commit
  19. 08 Dec, 2006 1 commit
  21. 07 Dec, 2006 1 commit
    • Eric Dumazet's avatar
      [PATCH] don't insert pipe dentries into dentry_hashtable. · d18de5a2
      Eric Dumazet authored 
      We currently insert pipe dentries into the global dentry hashtable.  This
is suboptimal because there is currently no way these entries can be used
for a lookup().  (/proc/xxx/fd/xxx uses a different mechanism).  Inserting
them in dentry hashtable slows dcache lookups.

To let __dpath() still work correctly (ie not adding a " (deleted)") after
dentry name, we do :

 - Right after d_alloc(), pretend they are hashed by clearing the
   DCACHE_UNHASHED bit.

 - Call d_instantiate() instead of d_add() : dentry is not inserted in
   hash table.

__dpath() & friends work as intended during dentry lifetime.

 - At dismantle time, once dput() must clear the dentry, setting again
   DCACHE_UNHASHED bit inside the custom d_delete() function provided by
   pipe code, so that dput() can just kill_it.

This patch, combined with (avoid RCU for never hashed dentries) reduced
time of { pipe(p); close(p[0]); close(p[1]);} on my UP machine (1.6GHz
Pentium-M) from 3.23 us to 2.86 us (But this patch does not depend on other
patches, only bench results)
Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
Acked-by: default avatarDavid Miller <davem@davemloft.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      d18de5a2
  23. 01 Oct, 2006 2 commits
  25. 27 Sep, 2006 1 commit
  27. 23 Jun, 2006 1 commit
    • David Howells's avatar
      [PATCH] VFS: Permit filesystem to override root dentry on mount · 454e2398
      David Howells authored 
      Extend the get_sb() filesystem operation to take an extra argument that
permits the VFS to pass in the target vfsmount that defines the mountpoint.

The filesystem is then required to manually set the superblock and root dentry
pointers.  For most filesystems, this should be done with simple_set_mnt()
which will set the superblock pointer and then set the root dentry to the
superblock's s_root (as per the old default behaviour).

The get_sb() op now returns an integer as there's now no need to return the
superblock pointer.

This patch permits a superblock to be implicitly shared amongst several mount
points, such as can be done with NFS to avoid potential inode aliasing.  In
such a case, simple_set_mnt() would not be called, and instead the mnt_root
and mnt_sb would be set directly.

The patch also makes the following changes:

 (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
     pointer argument and return an integer, so most filesystems have to change
     very little.

 (*) If one of the convenience function is not used, then get_sb() should
     normally call simple_set_mnt() to instantiate the vfsmount. This will
     always return 0, and so can be tail-called from get_sb().

 (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
     dcache upon superblock destruction rather than shrink_dcache_anon().

     This is required because the superblock may now have multiple trees that
     aren't actually bound to s_root, but that still need to be cleaned up. The
     currently called functions assume that the whole tree is rooted at s_root,
     and that anonymous dentries are not the roots of trees which results in
     dentries being left unculled.

     However, with the way NFS superblock sharing are currently set to be
     implemented, these assumptions are violated: the root of the filesystem is
     simply a dummy dentry and inode (the real inode for '/' may well be
     inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
     with child trees.

     [*] Anonymous until discovered from another tree.

 (*) The documentation has been adjusted, including the additional bit of
     changing ext2_* into foo_* in the documentation.

[akpm@osdl.org: convert ipath_fs, do other stuff]
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      454e2398
  29. 02 May, 2006 1 commit
  31. 01 May, 2006 3 commits
    • Jens Axboe's avatar
      [PATCH] pipe: enable atomic copying of pipe data to/from user space · f6762b7a
      Jens Axboe authored 
      The pipe ->map() method uses kmap() to virtually map the pages, which
is both slow and has known scalability issues on SMP. This patch enables
atomic copying of pipe pages, by pre-faulting data and using kmap_atomic()
instead.

lmbench bw_pipe and lat_pipe measurements agree this is a Good Thing. Here
are results from that on a UP machine with highmem (1.5GiB of RAM), running
first a UP kernel, SMP kernel, and SMP kernel patched.

Vanilla-UP:
Pipe bandwidth: 1622.28 MB/sec
Pipe bandwidth: 1610.59 MB/sec
Pipe bandwidth: 1608.30 MB/sec
Pipe latency: 7.3275 microseconds
Pipe latency: 7.2995 microseconds
Pipe latency: 7.3097 microseconds

Vanilla-SMP:
Pipe bandwidth: 1382.19 MB/sec
Pipe bandwidth: 1317.27 MB/sec
Pipe bandwidth: 1355.61 MB/sec
Pipe latency: 9.6402 microseconds
Pipe latency: 9.6696 microseconds
Pipe latency: 9.6153 microseconds

Patched-SMP:
Pipe bandwidth: 1578.70 MB/sec
Pipe bandwidth: 1579.95 MB/sec
Pipe bandwidth: 1578.63 MB/sec
Pipe latency: 9.1654 microseconds
Pipe latency: 9.2266 microseconds
Pipe latency: 9.1527 microseconds
Signed-off-by: default avatarJens Axboe <axboe@suse.de>
      f6762b7a
    • Jens Axboe's avatar
      [PATCH] pipe: introduce ->pin() buffer operation · f84d7519
      Jens Axboe authored 
      The ->map() function is really expensive on highmem machines right now,
since it has to use the slower kmap() instead of kmap_atomic(). Splice
rarely needs to access the virtual address of a page, so it's a waste
of time doing it.

Introduce ->pin() to take over the responsibility of making sure the
page data is valid. ->map() is then reduced to just kmap(). That way we
can also share a most of the pipe buffer ops between pipe.c and splice.c
Signed-off-by: default avatarJens Axboe <axboe@suse.de>
      f84d7519
    • Jens Axboe's avatar
      [PATCH] splice: fix bugs in pipe_to_file() · 0568b409
      Jens Axboe authored 
      Found by Oleg Nesterov <oleg@tv-sign.ru>, fixed by me.

- Only allow full pages to go to the page cache.
- Check page != buf->page instead of using PIPE_BUF_FLAG_STOLEN.
- Remember to clear 'stolen' if add_to_page_cache() fails.

And as a cleanup on that:

- Make the bottom fall-through logic a little less convoluted. Also make
  the steal path hold an extra reference to the page, so we don't have
  to differentiate between stolen and non-stolen at the end.
Signed-off-by: default avatarJens Axboe <axboe@suse.de>
      0568b409
  33. 30 Apr, 2006 1 commit
  35. 11 Apr, 2006 5 commits
  37. 10 Apr, 2006 1 commit
    • Ingo Molnar's avatar
      [PATCH] introduce a "kernel-internal pipe object" abstraction · 3a326a2c
      Ingo Molnar authored 
      separate out the 'internal pipe object' abstraction, and make it
usable to splice. This cleans up and fixes several aspects of the
internal splice APIs and the pipe code:

 - pipes: the allocation and freeing of pipe_inode_info is now more symmetric
   and more streamlined with existing kernel practices.

 - splice: small micro-optimization: less pointer dereferencing in splice
   methods
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>

Update XFS for the ->splice_read/->splice_write changes.
Signed-off-by: default avatarJens Axboe <axboe@suse.de>
      3a326a2c
  39. 02 Apr, 2006 2 commits
  41. 30 Mar, 2006 2 commits
    • Jens Axboe's avatar
      [PATCH] splice: add support for SPLICE_F_MOVE flag · 5abc97aa
      Jens Axboe authored 
      This enables the caller to migrate pages from one address space page
cache to another.  In buzz word marketing, you can do zero-copy file
copies!
Signed-off-by: default avatarJens Axboe <axboe@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5abc97aa
    • Jens Axboe's avatar
      [PATCH] Introduce sys_splice() system call · 5274f052
      Jens Axboe authored 
      This adds support for the sys_splice system call. Using a pipe as a
transport, it can connect to files or sockets (latter as output only).

From the splice.c comments:

   "splice": joining two ropes together by interweaving their strands.

   This is the "extended pipe" functionality, where a pipe is used as
   an arbitrary in-memory buffer. Think of a pipe as a small kernel
   buffer that you can use to transfer data from one end to the other.

   The traditional unix read/write is extended with a "splice()" operation
   that transfers data buffers to or from a pipe buffer.

   Named by Larry McVoy, original implementation from Linus, extended by
   Jens to support splicing to files and fixing the initial implementation
   bugs.
Signed-off-by: default avatarJens Axboe <axboe@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5274f052
  43. 28 Mar, 2006 1 commit
  45. 26 Mar, 2006 1 commit
  47. 25 Mar, 2006 1 commit
  49. 08 Mar, 2006 1 commit
  51. 15 Jan, 2006 1 commit
  53. 10 Jan, 2006 1 commit
  55. 09 Jan, 2006 1 commit
  57. 10 Sep, 2005 1 commit
    • Ingo Molnar's avatar
      [PATCH] sched: TASK_NONINTERACTIVE · d79fc0fc
      Ingo Molnar authored 
      This patch implements a task state bit (TASK_NONINTERACTIVE), which can be
used by blocking points to mark the task's wait as "non-interactive".  This
does not mean the task will be considered a CPU-hog - the wait will simply
not have an effect on the waiting task's priority - positive or negative
alike.  Right now only pipe_wait() will make use of it, because it's a
common source of not-so-interactive waits (kernel compilation jobs, etc.).
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      d79fc0fc
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