| Message ID | 20250226063043.732455-6-lizhijian@fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | migration/rdma: fixes, refactor and cleanup | expand |
On Wed, Feb 26, 2025 at 02:30:42PM +0800, Li Zhijian wrote: > control_save_page() is for RDMA only, unfold it to make the code more > clear. > In addition: > - Similar to other branches style in ram_save_target_page(), involve RDMA > only if the condition 'migrate_rdma()' is true. > - Further simplify the code by removing the RAM_SAVE_CONTROL_NOT_SUPP. > > Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> [...] > @@ -56,7 +55,7 @@ static inline > int rdma_control_save_page(QEMUFile *f, ram_addr_t block_offset, > ram_addr_t offset, size_t size) > { > - return RAM_SAVE_CONTROL_NOT_SUPP; > + g_assert_not_reached(); > } Not sure if some compiler will be unhappy on the retval not provided, but anyway we'll see.. Reviewed-by: Peter Xu <peterx@redhat.com> > #endif > #endif > -- > 2.44.0 >
On 26/02/2025 23:51, Peter Xu wrote: > On Wed, Feb 26, 2025 at 02:30:42PM +0800, Li Zhijian wrote: >> control_save_page() is for RDMA only, unfold it to make the code more >> clear. >> In addition: >> - Similar to other branches style in ram_save_target_page(), involve RDMA >> only if the condition 'migrate_rdma()' is true. >> - Further simplify the code by removing the RAM_SAVE_CONTROL_NOT_SUPP. >> >> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> > > [...] > >> @@ -56,7 +55,7 @@ static inline >> int rdma_control_save_page(QEMUFile *f, ram_addr_t block_offset, >> ram_addr_t offset, size_t size) >> { >> - return RAM_SAVE_CONTROL_NOT_SUPP; >> + g_assert_not_reached(); >> } > > Not sure if some compiler will be unhappy on the retval not provided, but > anyway we'll see.. There is no problem in fedora 40(gcc 14.2.1) and ubuntu2204(gcc 11.4.0) with --disable-rdma. I also noticed we have a few existing same usage: 1708 bool ram_write_tracking_compatible(void) 1709 { 1710 g_assert_not_reached(); 1711 } 1712 1713 int ram_write_tracking_start(void) 1714 { 1715 g_assert_not_reached(); 1716 } 1717 1718 void ram_write_tracking_stop(void) 1719 { 1720 g_assert_not_reached(); 1721 } I also asked the AI/Deepseek-R1, pasted a piece of his answer ``` 3. Why No Warning for Missing return?
On Thu, Feb 27, 2025 at 12:42:30AM +0000, Zhijian Li (Fujitsu) wrote: > > > On 26/02/2025 23:51, Peter Xu wrote: > > On Wed, Feb 26, 2025 at 02:30:42PM +0800, Li Zhijian wrote: > >> control_save_page() is for RDMA only, unfold it to make the code more > >> clear. > >> In addition: > >> - Similar to other branches style in ram_save_target_page(), involve RDMA > >> only if the condition 'migrate_rdma()' is true. > >> - Further simplify the code by removing the RAM_SAVE_CONTROL_NOT_SUPP. > >> > >> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> > > > > [...] > > > >> @@ -56,7 +55,7 @@ static inline > >> int rdma_control_save_page(QEMUFile *f, ram_addr_t block_offset, > >> ram_addr_t offset, size_t size) > >> { > >> - return RAM_SAVE_CONTROL_NOT_SUPP; > >> + g_assert_not_reached(); > >> } > > > > Not sure if some compiler will be unhappy on the retval not provided, but > > anyway we'll see.. > > There is no problem in fedora 40(gcc 14.2.1) and ubuntu2204(gcc 11.4.0) with --disable-rdma. > > I also noticed we have a few existing same usage: > > 1708 bool ram_write_tracking_compatible(void) > 1709 { > 1710 g_assert_not_reached(); > 1711 } > 1712 > 1713 int ram_write_tracking_start(void) > 1714 { > 1715 g_assert_not_reached(); > 1716 } > 1717 > 1718 void ram_write_tracking_stop(void) > 1719 { > 1720 g_assert_not_reached(); > 1721 } Right. The other question is what about G_DISABLE_ASSERT, then I found this: osdep.h: #ifdef G_DISABLE_ASSERT #error building with G_DISABLE_ASSERT is not supported #endif So yeah, we should be good. > > > I also asked the AI/Deepseek-R1, pasted a piece of his answer > > ``` > 3. Why No Warning for Missing return?
diff --git a/migration/ram.c b/migration/ram.c index 424df6d9f13..c363034c882 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1143,32 +1143,6 @@ static int save_zero_page(RAMState *rs, PageSearchStatus *pss, return len; } -/* - * @pages: the number of pages written by the control path, - * < 0 - error - * > 0 - number of pages written - * - * Return true if the pages has been saved, otherwise false is returned. - */ -static bool control_save_page(PageSearchStatus *pss, - ram_addr_t offset, int *pages) -{ - int ret; - - ret = rdma_control_save_page(pss->pss_channel, pss->block->offset, offset, - TARGET_PAGE_SIZE); - if (ret == RAM_SAVE_CONTROL_NOT_SUPP) { - return false; - } - - if (ret == RAM_SAVE_CONTROL_DELAYED) { - *pages = 1; - return true; - } - *pages = ret; - return true; -} - /* * directly send the page to the stream * @@ -1965,7 +1939,13 @@ static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss) int res; /* Hand over to RDMA first */ - if (control_save_page(pss, offset, &res)) { + if (migrate_rdma()) { + res = rdma_control_save_page(pss->pss_channel, pss->block->offset, + offset, TARGET_PAGE_SIZE); + + if (res == RAM_SAVE_CONTROL_DELAYED) { + res = 1; + } return res; } diff --git a/migration/rdma.c b/migration/rdma.c index e5b4ac599b1..08eb924ffaa 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -3284,14 +3284,11 @@ err: int rdma_control_save_page(QEMUFile *f, ram_addr_t block_offset, ram_addr_t offset, size_t size) { - if (!migrate_rdma()) { - return RAM_SAVE_CONTROL_NOT_SUPP; - } + assert(migrate_rdma()); int ret = qemu_rdma_save_page(f, block_offset, offset, size); - if (ret != RAM_SAVE_CONTROL_DELAYED && - ret != RAM_SAVE_CONTROL_NOT_SUPP) { + if (ret != RAM_SAVE_CONTROL_DELAYED) { if (ret < 0) { qemu_file_set_error(f, ret); } diff --git a/migration/rdma.h b/migration/rdma.h index f55f28bbed1..8eeb0117b91 100644 --- a/migration/rdma.h +++ b/migration/rdma.h @@ -33,7 +33,6 @@ void rdma_start_incoming_migration(InetSocketAddress *host_port, Error **errp); #define RAM_CONTROL_ROUND 1 #define RAM_CONTROL_FINISH 3 -#define RAM_SAVE_CONTROL_NOT_SUPP -1000 #define RAM_SAVE_CONTROL_DELAYED -2000 #ifdef CONFIG_RDMA @@ -56,7 +55,7 @@ static inline int rdma_control_save_page(QEMUFile *f, ram_addr_t block_offset, ram_addr_t offset, size_t size) { - return RAM_SAVE_CONTROL_NOT_SUPP; + g_assert_not_reached(); } #endif #endif
control_save_page() is for RDMA only, unfold it to make the code more clear. In addition: - Similar to other branches style in ram_save_target_page(), involve RDMA only if the condition 'migrate_rdma()' is true. - Further simplify the code by removing the RAM_SAVE_CONTROL_NOT_SUPP. Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> --- V3: squash previous 2nd, 3th, 4th into one patch --- migration/ram.c | 34 +++++++--------------------------- migration/rdma.c | 7 ++----- migration/rdma.h | 3 +-- 3 files changed, 10 insertions(+), 34 deletions(-)