Every patch of this patchset got at least one 'Reviewed-by' or 'Acked-by' from appropriate maintainers by last Wednesday, and after that, got no comment yet. May I ask some more comments? Thanks, SeongJae Park On Wed, 18 Dec 2019 19:37:13 +0100 SeongJae Park <sjpark@xxxxxxxxxx> wrote: > Granting pages consumes backend system memory. In systems configured > with insufficient spare memory for those pages, it can cause a memory > pressure situation. However, finding the optimal amount of the spare > memory is challenging for large systems having dynamic resource > utilization patterns. Also, such a static configuration might lack > flexibility. > > To mitigate such problems, this patchset adds a memory reclaim callback > to 'xenbus_driver' (patch 1) and then introduce a lock for race > condition avoidance (patch 2). After that, patch 3 applies the callback > mechanism to mitigate the problem in 'xen-blkback'. The fourth and > fifth patches are trivial cleanups; those fix nits we found during the > development of this patchset. > > Note that patches 1, 4, and 5 are not changed since v9. > > > Base Version > ------------ > > This patch is based on v5.4. A complete tree is also available at my > public git repo: > https://github.com/sjp38/linux/tree/patches/blkback/buffer_squeeze/v13 > > > Patch History > ------------- > > Changes from v12 > (https://lore.kernel.org/xen-devel/20191218104232.9606-1-sjpark@xxxxxxxxxx/) > - Do not unnecessarily disable interrupts (suggested by Juergen) > - Hold lock from xenbus side (suggested by Juergen) > > Changes from v11 > (https://lore.kernel.org/xen-devel/20191217160748.693-2-sjpark@xxxxxxxxxx/) > - Fix wrong trylock use (reported by Juergen) > - Merge patch 3 and 4 (suggested by Juergen) > - Update test result > > Changes from v10 > (https://lore.kernel.org/xen-devel/20191216124527.30306-1-sjpark@xxxxxxxxxx/) > - Fix race condition (reported by SeongJae, suggested by Juergen) > > Changes from v9 > (https://lore.kernel.org/xen-devel/20191213153546.17425-1-sjpark@xxxxxxxxx/) > - Add 'Reviewed-by' and 'Acked-by' from Roger Pau Monné > - Update the commit message for overhead test of the 2nd path > > Changes from v8 > (https://lore.kernel.org/xen-devel/20191213130211.24011-1-sjpark@xxxxxxxxx/) > - Drop 'Reviewed-by: Juergen' from the second patch > (suggested by Roger Pau Monné) > - Update contact of the new module param to SeongJae Park > <sjpark@xxxxxxxxx> > (suggested by Roger Pau Monné) > - Wordsmith the description of the parameter > (suggested by Roger Pau Monné) > - Fix dumb bugs > (suggested by Roger Pau Monné) > - Move module param definition to xenbus.c and reduce the number of > lines for this change > (suggested by Roger Pau Monné) > - Add a comment for the new callback, reclaim_memory, as other > callbacks also have > - Add another trivial cleanup of xenbus.c file (4th patch) > > Changes from v7 > (https://lore.kernel.org/xen-devel/20191211181016.14366-1-sjpark@xxxxxxxxx/) > - Update sysfs-driver-xen-blkback for new parameter > (suggested by Roger Pau Monné) > - Use per-xen_blkif buffer_squeeze_end instead of global variable > (suggested by Roger Pau Monné) > > Changes from v6 > (https://lore.kernel.org/linux-block/20191211042428.5961-1-sjpark@xxxxxxxxx/) > - Remove more unnecessary prefixes (suggested by Roger Pau Monné) > - Constify a variable (suggested by Roger Pau Monné) > - Rename 'reclaim' into 'reclaim_memory' (suggested by Roger Pau Monné) > - More wordsmith of the commit message (suggested by Roger Pau Monné) > > Changes from v5 > (https://lore.kernel.org/linux-block/20191210080628.5264-1-sjpark@xxxxxxxxx/) > - Wordsmith the commit messages (suggested by Roger Pau Monné) > - Change the reclaim callback return type (suggested by Roger Pau > Monné) > - Change the type of the blkback squeeze duration variable > (suggested by Roger Pau Monné) > - Add a patch for removal of unnecessary static variable name prefixes > (suggested by Roger Pau Monné) > - Fix checkpatch.pl warnings > > Changes from v4 > (https://lore.kernel.org/xen-devel/20191209194305.20828-1-sjpark@xxxxxxxxxx/) > - Remove domain id parameter from the callback (suggested by Juergen > Gross) > - Rename xen-blkback module parameter (suggested by Stefan Nuernburger) > > Changes from v3 > (https://lore.kernel.org/xen-devel/20191209085839.21215-1-sjpark@xxxxxxxxxx/) > - Add general callback in xen_driver and use it (suggested by Juergen > Gross) > > Changes from v2 > (https://lore.kernel.org/linux-block/af195033-23d5-38ed-b73b-f6e2e3b34541@xxxxxxxxxx) > - Rename the module parameter and variables for brevity > (aggressive shrinking -> squeezing) > > Changes from v1 > (https://lore.kernel.org/xen-devel/20191204113419.2298-1-sjpark@xxxxxxxxxx/) > - Adjust the description to not use the term, `arbitrarily` > (suggested by Paul Durrant) > - Specify time unit of the duration in the parameter description, > (suggested by Maximilian Heyne) > - Change default aggressive shrinking duration from 1ms to 10ms > - Merge two patches into one single patch > > > SeongJae Park (5): > xenbus/backend: Add memory pressure handler callback > xenbus/backend: Protect xenbus callback with lock > xen/blkback: Squeeze page pools if a memory pressure is detected > xen/blkback: Remove unnecessary static variable name prefixes > xen/blkback: Consistently insert one empty line between functions > > .../ABI/testing/sysfs-driver-xen-blkback | 10 +++++ > drivers/block/xen-blkback/blkback.c | 42 +++++++++---------- > drivers/block/xen-blkback/common.h | 1 + > drivers/block/xen-blkback/xenbus.c | 28 ++++++++++--- > drivers/xen/xenbus/xenbus_probe.c | 8 +++- > drivers/xen/xenbus/xenbus_probe_backend.c | 38 +++++++++++++++++ > include/xen/xenbus.h | 3 ++ > 7 files changed, 103 insertions(+), 27 deletions(-) > > -- > 2.17.1 >
