| Message ID | 20210812084148.14458-1-hreitz@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | block-status cache for data regions | expand |
On 12.08.21 10:41, Hanna Reitz wrote: > Hi, > > See the cover letter from v1 for the general idea: > https://lists.nongnu.org/archive/html/qemu-block/2021-06/msg00843.html > > Cover letter from v2, introducing RCU locking: > https://lists.nongnu.org/archive/html/qemu-block/2021-06/msg01060.html > > > v3: > - Patch 2: > - Add rcu_head object to BdrvBlockStatusCache, so we can use > g_free_rcu() to free it instead of synchronize_rcu()+g_free() > - Use qatomic_rcu_read() every time we read bs->block_status_cache > (except in bdrv_close(), where no concurrency is possible) > - Use RCU_READ_LOCK_GUARD() instead of WITH_RCU_READ_LOCK_GUARD() in > functions where we lock the whole scope anyway > - Same for QEMU_LOCK_GUARD() instead of WITH_QEMU_LOCK_GUARD() in > bdrv_bsc_fill() > - Drop from_cache variable in bdrv_co_block_status() > (was an artifact from v1, which had a different control flow and > needed this variable) > - Assert that local_map returned from a protocol driver’s > bdrv_co_block_status() implementation is equal to the offset we > passed to it (see comment there for why we should do this) > > - Patch 3: > - Add note why block drivers should return larger *pnum values in > addition to just saying that it’s allowed Thanks for the reviews, I’ve added the `local_file == bs` assertion in patch 2 as suggested by Vladimir (and updated the comment to match) and applied the series to my block branch: https://github.com/XanClic/qemu/commits/block Hanna
Hi, See the cover letter from v1 for the general idea: https://lists.nongnu.org/archive/html/qemu-block/2021-06/msg00843.html Cover letter from v2, introducing RCU locking: https://lists.nongnu.org/archive/html/qemu-block/2021-06/msg01060.html v3: - Patch 2: - Add rcu_head object to BdrvBlockStatusCache, so we can use g_free_rcu() to free it instead of synchronize_rcu()+g_free() - Use qatomic_rcu_read() every time we read bs->block_status_cache (except in bdrv_close(), where no concurrency is possible) - Use RCU_READ_LOCK_GUARD() instead of WITH_RCU_READ_LOCK_GUARD() in functions where we lock the whole scope anyway - Same for QEMU_LOCK_GUARD() instead of WITH_QEMU_LOCK_GUARD() in bdrv_bsc_fill() - Drop from_cache variable in bdrv_co_block_status() (was an artifact from v1, which had a different control flow and needed this variable) - Assert that local_map returned from a protocol driver’s bdrv_co_block_status() implementation is equal to the offset we passed to it (see comment there for why we should do this) - Patch 3: - Add note why block drivers should return larger *pnum values in addition to just saying that it’s allowed git-backport-diff against v2: Key: [----] : patches are identical [####] : number of functional differences between upstream/downstream patch [down] : patch is downstream-only The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively 001/6:[----] [--] 'block: Drop BDS comment regarding bdrv_append()' 002/6:[0063] [FC] 'block: block-status cache for data regions' 003/6:[0004] [FC] 'block: Clarify that @bytes is no limit on *pnum' 004/6:[----] [--] 'block/file-posix: Do not force-cap *pnum' 005/6:[----] [--] 'block/gluster: Do not force-cap *pnum' 006/6:[----] [--] 'block/iscsi: Do not force-cap *pnum' Hanna Reitz (6): block: Drop BDS comment regarding bdrv_append() block: block-status cache for data regions block: Clarify that @bytes is no limit on *pnum block/file-posix: Do not force-cap *pnum block/gluster: Do not force-cap *pnum block/iscsi: Do not force-cap *pnum include/block/block_int.h | 61 +++++++++++++++++++++++++++-- block.c | 80 +++++++++++++++++++++++++++++++++++++++ block/file-posix.c | 7 ++-- block/gluster.c | 7 ++-- block/io.c | 65 +++++++++++++++++++++++++++++-- block/iscsi.c | 3 -- 6 files changed, 207 insertions(+), 16 deletions(-)