| Message ID | 20201201082128.15239-1-jgross@suse.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | xen: support per-cpupool scheduling granularity | expand |
On 01/12/2020 08:21, Juergen Gross wrote: > Support scheduling granularity per cpupool. Setting the granularity is > done via hypfs, which needed to gain dynamical entries for that > purpose. > > Apart from the hypfs related additional functionality the main change > for cpupools was the support for moving a domain to a new granularity, > as this requires to modify the scheduling unit/vcpu relationship. > > I have tried to do the hypfs modifications in a rather generic way in > order to be able to use the same infrastructure in other cases, too > (e.g. for per-domain entries). > > The complete series has been tested by creating cpupools with different > granularities and moving busy and idle domains between those. > > Changes in V2: > - Added several new patches, especially for some further cleanups in > cpupool.c. > - Completely reworked the locking scheme with dynamical directories: > locking of resources (cpupools in this series) is now done via new > callbacks which are called when traversing the hypfs tree. This > removes the need to add locking to each hypfs related cpupool > function and it ensures data integrity across multiple callbacks. > - Reordered the first few patches in order to have already acked > patches in pure cleanup patches first. > - Addressed several comments. > > Juergen Gross (17): > xen/cpupool: add cpu to sched_res_mask when removing it from cpupool > xen/cpupool: add missing bits for per-cpupool scheduling granularity > xen/cpupool: sort included headers in cpupool.c > xen/cpupool: switch cpupool id to unsigned > xen/cpupool: switch cpupool list to normal list interface > xen/cpupool: use ERR_PTR() for returning error cause from > cpupool_create() > xen/cpupool: support moving domain between cpupools with different > granularity > docs: fix hypfs path documentation > xen/hypfs: move per-node function pointers into a dedicated struct > xen/hypfs: pass real failure reason up from hypfs_get_entry() > xen/hypfs: add getsize() and findentry() callbacks to hypfs_funcs > xen/hypfs: add new enter() and exit() per node callbacks > xen/hypfs: support dynamic hypfs nodes > xen/hypfs: add support for id-based dynamic directories > xen/cpupool: add cpupool directories > xen/cpupool: add scheduling granularity entry to cpupool entries > xen/cpupool: make per-cpupool sched-gran hypfs node writable Gitlab CI is fairly (but not completely) reliably hitting an failure in ARM randconfig against this series only. https://gitlab.com/xen-project/patchew/xen/-/pipelines/225445864 is one example. Error is: cpupool.c:102:12: error: 'sched_gran_get' defined but not used [-Werror=unused-function] 102 | static int sched_gran_get(const char *str, enum sched_gran *mode) | ^~~~~~~~~~~~~~ Weirdly, there is a second diagnostic showing up which appears to be unrelated and non-fatal, but a concerning non-the-less mem_access.c: In function 'p2m_mem_access_check': mem_access.c:227:6: note: parameter passing for argument of type 'const struct npfec' changed in GCC 9.1 227 | bool p2m_mem_access_check(paddr_t gpa, vaddr_t gla, const struct npfec npfec) | ^~~~~~~~~~~~~~~~~~~~ It appears to be related to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88469 and is letting us know that the ABI changed. However, Xen is an embedded project with no external linkage, so we can probably compile with -Wno-psabi and be done with it. ~Andrew, in lieu of a real CI robot.
On 05.12.20 00:53, Andrew Cooper wrote: > On 01/12/2020 08:21, Juergen Gross wrote: >> Support scheduling granularity per cpupool. Setting the granularity is >> done via hypfs, which needed to gain dynamical entries for that >> purpose. >> >> Apart from the hypfs related additional functionality the main change >> for cpupools was the support for moving a domain to a new granularity, >> as this requires to modify the scheduling unit/vcpu relationship. >> >> I have tried to do the hypfs modifications in a rather generic way in >> order to be able to use the same infrastructure in other cases, too >> (e.g. for per-domain entries). >> >> The complete series has been tested by creating cpupools with different >> granularities and moving busy and idle domains between those. >> >> Changes in V2: >> - Added several new patches, especially for some further cleanups in >> cpupool.c. >> - Completely reworked the locking scheme with dynamical directories: >> locking of resources (cpupools in this series) is now done via new >> callbacks which are called when traversing the hypfs tree. This >> removes the need to add locking to each hypfs related cpupool >> function and it ensures data integrity across multiple callbacks. >> - Reordered the first few patches in order to have already acked >> patches in pure cleanup patches first. >> - Addressed several comments. >> >> Juergen Gross (17): >> xen/cpupool: add cpu to sched_res_mask when removing it from cpupool >> xen/cpupool: add missing bits for per-cpupool scheduling granularity >> xen/cpupool: sort included headers in cpupool.c >> xen/cpupool: switch cpupool id to unsigned >> xen/cpupool: switch cpupool list to normal list interface >> xen/cpupool: use ERR_PTR() for returning error cause from >> cpupool_create() >> xen/cpupool: support moving domain between cpupools with different >> granularity >> docs: fix hypfs path documentation >> xen/hypfs: move per-node function pointers into a dedicated struct >> xen/hypfs: pass real failure reason up from hypfs_get_entry() >> xen/hypfs: add getsize() and findentry() callbacks to hypfs_funcs >> xen/hypfs: add new enter() and exit() per node callbacks >> xen/hypfs: support dynamic hypfs nodes >> xen/hypfs: add support for id-based dynamic directories >> xen/cpupool: add cpupool directories >> xen/cpupool: add scheduling granularity entry to cpupool entries >> xen/cpupool: make per-cpupool sched-gran hypfs node writable > > Gitlab CI is fairly (but not completely) reliably hitting an failure in > ARM randconfig against this series only. > > https://gitlab.com/xen-project/patchew/xen/-/pipelines/225445864 is one > example. > > Error is: > > cpupool.c:102:12: error: 'sched_gran_get' defined but not used > [-Werror=unused-function] > 102 | static int sched_gran_get(const char *str, enum sched_gran *mode) > | ^~~~~~~~~~~~~~ > Ah, this is without CONFIG_HYPFS. Will fix. Juergen
On 05.12.2020 00:53, Andrew Cooper wrote: > Weirdly, there is a second diagnostic showing up which appears to be > unrelated and non-fatal, but a concerning non-the-less > > mem_access.c: In function 'p2m_mem_access_check': > mem_access.c:227:6: note: parameter passing for argument of type 'const > struct npfec' changed in GCC 9.1 > 227 | bool p2m_mem_access_check(paddr_t gpa, vaddr_t gla, const struct > npfec npfec) > | ^~~~~~~~~~~~~~~~~~~~ > > It appears to be related to > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88469 and is letting us > know that the ABI changed. However, Xen is an embedded project with no > external linkage, so we can probably compile with -Wno-psabi and be done > with it. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91710 I have no idea why the fix suggested there hasn't made it into the code base yet - iirc I had taken it verbatim and it got rid of the problem in my builds of the compiler. I don't, btw, think us being "embedded" is an excuse to suppress the warning. If there really was a code generation difference here (and not just a false positive warning), an incremental build across a switch between older and newer gcc would then be broken. Jan
Support scheduling granularity per cpupool. Setting the granularity is done via hypfs, which needed to gain dynamical entries for that purpose. Apart from the hypfs related additional functionality the main change for cpupools was the support for moving a domain to a new granularity, as this requires to modify the scheduling unit/vcpu relationship. I have tried to do the hypfs modifications in a rather generic way in order to be able to use the same infrastructure in other cases, too (e.g. for per-domain entries). The complete series has been tested by creating cpupools with different granularities and moving busy and idle domains between those. Changes in V2: - Added several new patches, especially for some further cleanups in cpupool.c. - Completely reworked the locking scheme with dynamical directories: locking of resources (cpupools in this series) is now done via new callbacks which are called when traversing the hypfs tree. This removes the need to add locking to each hypfs related cpupool function and it ensures data integrity across multiple callbacks. - Reordered the first few patches in order to have already acked patches in pure cleanup patches first. - Addressed several comments. Juergen Gross (17): xen/cpupool: add cpu to sched_res_mask when removing it from cpupool xen/cpupool: add missing bits for per-cpupool scheduling granularity xen/cpupool: sort included headers in cpupool.c xen/cpupool: switch cpupool id to unsigned xen/cpupool: switch cpupool list to normal list interface xen/cpupool: use ERR_PTR() for returning error cause from cpupool_create() xen/cpupool: support moving domain between cpupools with different granularity docs: fix hypfs path documentation xen/hypfs: move per-node function pointers into a dedicated struct xen/hypfs: pass real failure reason up from hypfs_get_entry() xen/hypfs: add getsize() and findentry() callbacks to hypfs_funcs xen/hypfs: add new enter() and exit() per node callbacks xen/hypfs: support dynamic hypfs nodes xen/hypfs: add support for id-based dynamic directories xen/cpupool: add cpupool directories xen/cpupool: add scheduling granularity entry to cpupool entries xen/cpupool: make per-cpupool sched-gran hypfs node writable docs/misc/hypfs-paths.pandoc | 18 +- xen/common/hypfs.c | 336 ++++++++++++++++++++++---- xen/common/sched/core.c | 137 ++++++++--- xen/common/sched/cpupool.c | 446 +++++++++++++++++++++++++++-------- xen/common/sched/private.h | 15 +- xen/include/xen/hypfs.h | 140 ++++++++--- xen/include/xen/param.h | 15 +- xen/include/xen/sched.h | 4 +- 8 files changed, 875 insertions(+), 236 deletions(-)