* Re: [PATCH 2/7] writeback: switch to per-bdi threads for flushing data [not found] ` <1236868428-20408-3-git-send-email-jens.axboe@oracle.com> @ 2009-03-16 10:22 ` Christoph Hellwig 2009-03-16 13:30 ` Chris Mason 0 siblings, 1 reply; 3+ messages in thread From: Christoph Hellwig @ 2009-03-16 10:22 UTC (permalink / raw) To: Jens Axboe Cc: linux-kernel, linux-fsdevel, chris.mason, david, npiggin, linux-mm On Thu, Mar 12, 2009 at 03:33:43PM +0100, Jens Axboe wrote: > +static void bdi_kupdated(struct backing_dev_info *bdi) > +{ > + long nr_to_write; > + struct writeback_control wbc = { > + .bdi = bdi, > + .sync_mode = WB_SYNC_NONE, > + .nr_to_write = 0, > + .for_kupdate = 1, > + .range_cyclic = 1, > + }; > + > + sync_supers(); Not directly related to your patch, but can someone explain WTF sync_supers is doing here or in the old kupdated? We're writing back dirty pages from the VM, and for some reason we try to also write back superblocks. This doesn't really make any sense. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 2/7] writeback: switch to per-bdi threads for flushing data 2009-03-16 10:22 ` [PATCH 2/7] writeback: switch to per-bdi threads for flushing data Christoph Hellwig @ 2009-03-16 13:30 ` Chris Mason 2009-03-16 13:39 ` Christoph Hellwig 0 siblings, 1 reply; 3+ messages in thread From: Chris Mason @ 2009-03-16 13:30 UTC (permalink / raw) To: Christoph Hellwig Cc: Jens Axboe, linux-kernel, linux-fsdevel, david, npiggin, linux-mm On Mon, 2009-03-16 at 06:22 -0400, Christoph Hellwig wrote: > On Thu, Mar 12, 2009 at 03:33:43PM +0100, Jens Axboe wrote: > > +static void bdi_kupdated(struct backing_dev_info *bdi) > > +{ > > + long nr_to_write; > > + struct writeback_control wbc = { > > + .bdi = bdi, > > + .sync_mode = WB_SYNC_NONE, > > + .nr_to_write = 0, > > + .for_kupdate = 1, > > + .range_cyclic = 1, > > + }; > > + > > + sync_supers(); > > Not directly related to your patch, but can someone explain WTF > sync_supers is doing here or in the old kupdated? We're writing back > dirty pages from the VM, and for some reason we try to also write back > superblocks. This doesn't really make any sense. Some of our poor filesystem cousins don't write the super until kupdate kicks them (see ext2_write_super). kupdate has always been the periodic FS thread of last resort. -chris -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 2/7] writeback: switch to per-bdi threads for flushing data 2009-03-16 13:30 ` Chris Mason @ 2009-03-16 13:39 ` Christoph Hellwig 0 siblings, 0 replies; 3+ messages in thread From: Christoph Hellwig @ 2009-03-16 13:39 UTC (permalink / raw) To: Chris Mason Cc: Christoph Hellwig, Jens Axboe, linux-kernel, linux-fsdevel, david, npiggin, linux-mm On Mon, Mar 16, 2009 at 09:30:14AM -0400, Chris Mason wrote: > Some of our poor filesystem cousins don't write the super until kupdate > kicks them (see ext2_write_super). kupdate has always been the periodic > FS thread of last resort. Yikes, looks like this is indeed the only peridocial sb update for many simpler filesystems. We should really have a separate thread for that instead of hacking it into VM writeback. Especially with the per-bdi one where the current setup doesn't make any sense. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 3+ messages in thread
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2009-03-16 10:22 ` [PATCH 2/7] writeback: switch to per-bdi threads for flushing data Christoph Hellwig
2009-03-16 13:30 ` Chris Mason
2009-03-16 13:39 ` Christoph Hellwig
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