1. 16 Feb, 2009 2 commits
    • Steven Rostedt's avatar
      ftrace: add do_for_each_ftrace_rec and while_for_each_ftrace_rec · 265c831c
      Steven Rostedt authored
      Impact: clean up
      
      To iterate over all the functions that dynamic trace knows about
      it requires two for loops. One to iterate over the pages and the
      other to iterate over the records within the page.
      
      There are several duplications of these loops in ftrace.c. This
      patch creates the macros do_for_each_ftrace_rec and
      while_for_each_ftrace_rec to handle this logic, and removes the
      duplicate code.
      
      While making this change, I also discovered and fixed a small
      bug that one of the iterations should exit the loop after it found the
      record it was searching for. This used a break when it should have
      used a goto, since there were two loops it needed to break out
      from.  No real harm was done by this bug since it would only continue
      to search the other records, and the code was in a slow path anyway.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      265c831c
    • Steven Rostedt's avatar
      ftrace: state that all functions are enabled in set_ftrace_filter · 0c75a3ed
      Steven Rostedt authored
      Impact: clean up, make set_ftrace_filter less confusing
      
      The set_ftrace_filter shows only the functions that will be traced.
      But when it is empty, it will trace all functions. This can be a bit
      confusing.
      
      This patch makes set_ftrace_filter show:
      
        #### all functions enabled ####
      
      When all functions will be traced, and we do not filter only a select
      few.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      0c75a3ed
  2. 13 Feb, 2009 3 commits
  3. 12 Feb, 2009 7 commits
    • Steven Rostedt's avatar
      sched: do not account for NMIs · 2a7b8df0
      Steven Rostedt authored
      Impact: avoid corruption in system time accounting
      
      Martin Schwidefsky told me that there was an issue with NMIs and
      system accounting. The problem is that the accounting code is
      not reentrant, and if an NMI goes off after an interrupt it can
      corrupt the accounting.
      
      For now, the best we can do is to treat NMIs like SMIs and they
      are not accounted for.
      
      This patch changes nmi_enter to not call __irq_enter and to do
      the preempt-count and tracing calls directly.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      2a7b8df0
    • Steven Rostedt's avatar
      ring-buffer: rename label out_unlock to out_reset · 45141d46
      Steven Rostedt authored
      Impact: clean up
      
      While reviewing the ring buffer code, I thougth I saw a bug with
      
      	if (!__raw_spin_trylock(&cpu_buffer->lock))
      		goto out_unlock;
      
      But I forgot that we use a variable "lock_taken" that is set if
      the spinlock is taken, and only unlock it if that variable is set.
      
      To avoid further confusion from other reviewers, this patch
      renames the label out_unlock with out_reset, which is the more
      appropriate name.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      45141d46
    • Linus Torvalds's avatar
    • Steven Rostedt's avatar
      preempt-count: force hardirq-count to max of 10 · 5a5fb7db
      Steven Rostedt authored
      To add a bit in the preempt_count to be set when in NMI context, we
      found that some archs did not have enough bits to spare. This is
      due to the hardirq_count being a mask that can hold NR_IRQS.
      
      Some archs allow for over 16000 IRQs, and that would require a mask
      of 14 bits. The sofitrq mask is 8 bits and the preempt disable mask
      is also 8 bits.  The PREEMP_ACTIVE bit is bit 30, and bit 31 would
      make the preempt_count (which is type int) a negative number.
      A negative preempt_count is a sign of failure.
      
      Add them up 14+8+8+1+1 you get 32 bits. No room for the NMI bit.
      
      But the hardirq_count is to track the number of nested IRQs, not
      the number of total IRQs.  This originally took the paranoid approach
      of setting the max nesting to NR_IRQS. But when we have archs with
      over 1000 IRQs, it is not practical to think they will ever all
      nest on a single CPU. Not to mention that this would most definitely
      cause a stack overflow.
      
      This patch sets a max of 10 bits to be used for IRQ nesting.
      I did a 'git grep HARDIRQ' to examine all users of HARDIRQ_BITS and
      HARDIRQ_MASK, and found that making it a max of 10 would not hurt
      anyone. I did find that the m68k expected it to be 8 bits, so
      I allow for the archs to set the number to be less than 10.
      
      I removed the setting of HARDIRQ_BITS from the archs that set it
      to more than 10. This includes ALPHA, ia64 and avr32.
      
      This will always allow room for the NMI bit, and if we need to allow
      for NMI nesting, we have 4 bits to play with.
      Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
      5a5fb7db
    • Nick Piggin's avatar
      Fix page writeback thinko, causing Berkeley DB slowdown · 3a4c6800
      Nick Piggin authored
      A bug was introduced into write_cache_pages cyclic writeout by commit
      31a12666 ("mm: write_cache_pages cyclic
      fix").  The intention (and comments) is that we should cycle back and
      look for more dirty pages at the beginning of the file if there is no
      more work to be done.
      
      But the !done condition was dropped from the test.  This means that any
      time the page writeout loop breaks (eg.  due to nr_to_write == 0), we
      will set index to 0, then goto again.  This will set done_index to
      index, then find done is set, so will proceed to the end of the
      function.  When updating mapping->writeback_index for cyclic writeout,
      we now use done_index == 0, so we're always cycling back to 0.
      
      This seemed to be causing random mmap writes (slapadd and iozone) to
      start writing more pages from the LRU and writeout would slowdown, and
      caused bugzilla entry
      
      	http://bugzilla.kernel.org/show_bug.cgi?id=12604
      
      about Berkeley DB slowing down dramatically.
      
      With this patch, iozone random write performance is increased nearly
      5x on my system (iozone -B -r 4k -s 64k -s 512m -s 1200m on ext2).
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Reported-and-tested-by: default avatarJan Kara <jack@suse.cz>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3a4c6800
    • Kirill A. Shutemov's avatar
      mm: Export symbol ksize() · b1aabecd
      Kirill A. Shutemov authored
      Commit 7b2cd92a ("crypto: api - Fix
      zeroing on free") added modular user of ksize(). Export that to fix
      crypto.ko compilation.
      
      Cc: Herbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarKirill A. Shutemov <kirill@shutemov.name>
      Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
      b1aabecd
    • Linus Torvalds's avatar
  4. 11 Feb, 2009 28 commits