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  1. 04 10月, 2006 1 次提交
    • O
      [PATCH] rcu: simplify/improve batch tuning · 20e9751b
      由 Oleg Nesterov 提交于 
      Kill a hard-to-calculate 'rsinterval' boot parameter and per-cpu
rcu_data.last_rs_qlen.  Instead, it adds adds a flag rcu_ctrlblk.signaled,
which records the fact that one of CPUs has sent a resched IPI since the
last rcu_start_batch().

Roughly speaking, we need two rcu_start_batch()s in order to move callbacks
from ->nxtlist to ->donelist.  This means that when ->qlen exceeds qhimark
and continues to grow, we should send a resched IPI, and then do it again
after we gone through a quiescent state.

On the other hand, if it was already sent, we don't need to do it again
when another CPU detects overflow of the queue.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Acked-by: NPaul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      20e9751b
  3. 01 7月, 2006 1 次提交
  5. 28 6月, 2006 1 次提交
  7. 23 6月, 2006 1 次提交
  9. 16 5月, 2006 1 次提交
  11. 23 3月, 2006 1 次提交
  13. 09 3月, 2006 1 次提交
    • D
      [PATCH] rcu batch tuning · 21a1ea9e
      由 Dipankar Sarma 提交于 
      This patch adds new tunables for RCU queue and finished batches.  There are
two types of controls - number of completed RCU updates invoked in a batch
(blimit) and monitoring for high rate of incoming RCUs on a cpu (qhimark,
qlowmark).

By default, the per-cpu batch limit is set to a small value.  If the input
RCU rate exceeds the high watermark, we do two things - force quiescent
state on all cpus and set the batch limit of the CPU to INTMAX.  Setting
batch limit to INTMAX forces all finished RCUs to be processed in one shot.
 If we have more than INTMAX RCUs queued up, then we have bigger problems
anyway.  Once the incoming queued RCUs fall below the low watermark, the
batch limit is set to the default.
Signed-off-by: NDipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      21a1ea9e
  15. 04 2月, 2006 1 次提交
  17. 11 1月, 2006 1 次提交
  19. 10 1月, 2006 1 次提交
  21. 09 1月, 2006 1 次提交
  23. 13 12月, 2005 1 次提交
    • D
      [PATCH] add rcu_barrier() synchronization point · ab4720ec
      由 Dipankar Sarma 提交于 
      This introduces a new interface - rcu_barrier() which waits until all
the RCUs queued until this call have been completed.

Reiser4 needs this, because we do more than just freeing memory object
in our RCU callback: we also remove it from the list hanging off
super-block.  This means, that before freeing reiser4-specific portion
of super-block (during umount) we have to wait until all pending RCU
callbacks are executed.

The only change of reiser4 made to the original patch, is exporting of
rcu_barrier().

Cc: Hans Reiser <reiser@namesys.com>
Cc: Vladimir V. Saveliev <vs@namesys.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      ab4720ec
  25. 31 10月, 2005 1 次提交
  27. 18 10月, 2005 1 次提交
  29. 10 9月, 2005 1 次提交
    • D
      [PATCH] files: fix rcu initializers · 8b6490e5
      由 Dipankar Sarma 提交于 
      First of a number of files_lock scaability patches.

 Here are the x86 numbers -

 tiobench on a 4(8)-way (HT) P4 system on ramdisk :

                                         (lockfree)
 Test            2.6.10-vanilla  Stdev   2.6.10-fd       Stdev
 -------------------------------------------------------------
 Seqread         1400.8          11.52   1465.4          34.27
 Randread        1594            8.86    2397.2          29.21
 Seqwrite        242.72          3.47    238.46          6.53
 Randwrite       445.74          9.15    446.4           9.75

 The performance improvement is very significant.
 We are getting killed by the cacheline bouncing of the files_struct
 lock here. Writes on ramdisk (ext2) seems to vary just too
 much to get any meaningful number.

 Also, With Tridge's thread_perf test on a 4(8)-way (HT) P4 xeon system :

 2.6.12-rc5-vanilla :

 Running test 'readwrite' with 8 tasks
 Threads     0.34 +/- 0.01 seconds
 Processes   0.16 +/- 0.00 seconds

 2.6.12-rc5-fd :

 Running test 'readwrite' with 8 tasks
 Threads     0.17 +/- 0.02 seconds
 Processes   0.17 +/- 0.02 seconds

 I repeated the measurements on ramfs (as opposed to ext2 on ramdisk in
 the earlier measurement) and I got more consistent results from tiobench :

 4(8) way xeon P4
 -----------------
                                         (lock-free)
 Test            2.6.12-rc5      Stdev   2.6.12-rc5-fd   Stdev
 -------------------------------------------------------------
 Seqread         1282            18.59   1343.6          26.37
 Randread        1517            7       2415            34.27
 Seqwrite        702.2           5.27    709.46           5.9
 Randwrite       846.86          15.15   919.68          21.4

 4-way ppc64
 ------------
                                         (lock-free)
 Test            2.6.12-rc5      Stdev   2.6.12-rc5-fd   Stdev
 -------------------------------------------------------------
 Seqread         1549            91.16   1569.6          47.2
 Randread        1473.6          25.11   1585.4          69.99
 Seqwrite        1096.8          20.03   1136            29.61
 Randwrite       1189.6           4.04   1275.2          32.96

 Also running Tridge's thread_perf test on ppc64 :

 2.6.12-rc5-vanilla
 --------------------
 Running test 'readwrite' with 4 tasks
 Threads     0.20 +/- 0.02 seconds
 Processes   0.16 +/- 0.01 seconds

 2.6.12-rc5-fd
 --------------------
 Running test 'readwrite' with 4 tasks
 Threads     0.18 +/- 0.04 seconds
 Processes   0.16 +/- 0.01 seconds

 The benefits are huge (upto ~60%) in some cases on x86 primarily
 due to the atomic operations during acquisition of ->file_lock
 and cache line bouncing in fast path. ppc64 benefits are modest
 due to LL/SC based locking, but still statistically significant.

This patch:

RCU head initilizer no longer needs the head varible name since we don't use
list.h lists anymore.
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>
      8b6490e5
  31. 01 5月, 2005 1 次提交
    • P
      [PATCH] Deprecate synchronize_kernel, GPL replacement · 9b06e818
      由 Paul E. McKenney 提交于 
      The synchronize_kernel() primitive is used for quite a few different purposes:
waiting for RCU readers, waiting for NMIs, waiting for interrupts, and so on.
This makes RCU code harder to read, since synchronize_kernel() might or might
not have matching rcu_read_lock()s.  This patch creates a new
synchronize_rcu() that is to be used for RCU readers and a new
synchronize_sched() that is used for the rest.  These two new primitives
currently have the same implementation, but this is might well change with
additional real-time support.  Both new primitives are GPL-only, the old
primitive is deprecated.
Signed-off-by: NPaul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      9b06e818
  33. 17 4月, 2005 1 次提交
    • L
      Linux-2.6.12-rc2 · 1da177e4
      由 Linus Torvalds 提交于 
      Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
      1da177e4