1. 23 Jan, 2015 1 commit
    • Shaohua Li's avatar
      block: support different tag allocation policy · ee1b6f7a
      Shaohua Li authored
      The libata tag allocation is using a round-robin policy. Next patch will
      make libata use block generic tag allocation, so let's add a policy to
      tag allocation.
      
      Currently two policies: FIFO (default) and round-robin.
      
      Cc: Jens Axboe <axboe@fb.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Christoph Hellwig <hch@infradead.org>
      Signed-off-by: default avatarShaohua Li <shli@fb.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      ee1b6f7a
  2. 08 Jul, 2014 1 commit
  3. 28 Jun, 2013 1 commit
    • Jan Kara's avatar
      block: Reserve only one queue tag for sync IO if only 3 tags are available · a6b3f761
      Jan Kara authored
      In case a device has three tags available we still reserve two of them
      for sync IO. That leaves only a single tag for async IO such as
      writeback from flusher thread which results in poor performance.
      
      Allow async IO to consume two tags in case queue has three tag availabe
      to get a decent async write performance.
      
      This patch improves streaming write performance on a machine with such disk
      from ~21 MB/s to ~52 MB/s. Also postmark throughput in presence of
      streaming writer improves from 8 to 12 transactions per second so sync
      IO doesn't seem to be harmed in presence of heavy async writer.
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      a6b3f761
  4. 12 Sep, 2012 1 commit
    • Peter Senna Tschudin's avatar
      block/blk-tag.c: Remove useless kfree · d41570b7
      Peter Senna Tschudin authored
      Remove useless kfree() and clean up code related to the removal.
      
      The semantic patch that finds this problem is as follows:
      (http://coccinelle.lip6.fr/)
      
      // <smpl>
      @r exists@
      position p1,p2;
      expression x;
      @@
      
      if (x@p1 == NULL) { ... kfree@p2(x); ... return ...; }
      
      @unchanged exists@
      position r.p1,r.p2;
      expression e <= r.x,x,e1;
      iterator I;
      statement S;
      @@
      
      if (x@p1 == NULL) { ... when != I(x,...) S
                              when != e = e1
                              when != e += e1
                              when != e -= e1
                              when != ++e
                              when != --e
                              when != e++
                              when != e--
                              when != &e
         kfree@p2(x); ... return ...; }
      
      @ok depends on unchanged exists@
      position any r.p1;
      position r.p2;
      expression x;
      @@
      
      ... when != true x@p1 == NULL
      kfree@p2(x);
      
      @depends on !ok && unchanged@
      position r.p2;
      expression x;
      @@
      
      *kfree@p2(x);
      // </smpl>
      Signed-off-by: default avatarPeter Senna Tschudin <peter.senna@gmail.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      d41570b7
  5. 29 Dec, 2011 1 commit
  6. 25 Oct, 2011 1 commit
  7. 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
  8. 06 Oct, 2009 1 commit
  9. 20 May, 2009 1 commit
  10. 11 May, 2009 1 commit
    • Tejun Heo's avatar
      block: implement and enforce request peek/start/fetch · 9934c8c0
      Tejun Heo authored
      Till now block layer allowed two separate modes of request execution.
      A request is always acquired from the request queue via
      elv_next_request().  After that, drivers are free to either dequeue it
      or process it without dequeueing.  Dequeue allows elv_next_request()
      to return the next request so that multiple requests can be in flight.
      
      Executing requests without dequeueing has its merits mostly in
      allowing drivers for simpler devices which can't do sg to deal with
      segments only without considering request boundary.  However, the
      benefit this brings is dubious and declining while the cost of the API
      ambiguity is increasing.  Segment based drivers are usually for very
      old or limited devices and as converting to dequeueing model isn't
      difficult, it doesn't justify the API overhead it puts on block layer
      and its more modern users.
      
      Previous patches converted all block low level drivers to dequeueing
      model.  This patch completes the API transition by...
      
      * renaming elv_next_request() to blk_peek_request()
      
      * renaming blkdev_dequeue_request() to blk_start_request()
      
      * adding blk_fetch_request() which is combination of peek and start
      
      * disallowing completion of queued (not started) requests
      
      * applying new API to all LLDs
      
      Renamings are for consistency and to break out of tree code so that
      it's apparent that out of tree drivers need updating.
      
      [ Impact: block request issue API cleanup, no functional change ]
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
      Cc: Mike Miller <mike.miller@hp.com>
      Cc: unsik Kim <donari75@gmail.com>
      Cc: Paul Clements <paul.clements@steeleye.com>
      Cc: Tim Waugh <tim@cyberelk.net>
      Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Laurent Vivier <Laurent@lvivier.info>
      Cc: Jeff Garzik <jgarzik@pobox.com>
      Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
      Cc: Grant Likely <grant.likely@secretlab.ca>
      Cc: Adrian McMenamin <adrian@mcmen.demon.co.uk>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
      Cc: Borislav Petkov <petkovbb@googlemail.com>
      Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
      Cc: Alex Dubov <oakad@yahoo.com>
      Cc: Pierre Ossman <drzeus@drzeus.cx>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
      Cc: Stefan Weinhuber <wein@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Pete Zaitcev <zaitcev@redhat.com>
      Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      9934c8c0
  11. 29 Dec, 2008 1 commit
  12. 09 Oct, 2008 2 commits
  13. 27 Aug, 2008 1 commit
  14. 07 May, 2008 1 commit
    • Jens Axboe's avatar
      block: adjust tagging function queue bit locking · aa94b537
      Jens Axboe authored
      For most initialization purposes, calling blk_queue_init_tags() without
      the queue lock held is OK. Only if called for resizing an existing map
      must the lock be held. Ditto for tag cleanup, the maps are reference
      counted.
      
      So switch the general queue flag setting to the unlocked variant, but
      retain the locked variant for resizing.
      Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      aa94b537
  15. 01 May, 2008 1 commit
  16. 29 Apr, 2008 1 commit
  17. 04 Mar, 2008 1 commit
  18. 01 Feb, 2008 1 commit
  19. 29 Jan, 2008 1 commit