| Message ID | 1391066055-17024-7-git-send-email-owasserm@redhat.com |
|---|---|
| State | New |
| Headers | show |
* Orit Wasserman (owasserm@redhat.com) wrote: > It is better to fail migration in case of failure to > allocate new cache item Does this actually fail migration or just drop back to sending an uncompressed page? (I think the latter, and that's an even better result). > Signed-off-by: Orit Wasserman <owasserm@redhat.com> > --- > arch_init.c | 4 +++- > include/migration/page_cache.h | 4 +++- > page_cache.c | 16 +++++++++++----- > 3 files changed, 17 insertions(+), 7 deletions(-) > > diff --git a/arch_init.c b/arch_init.c > index 806d096..0bfbc5a 100644 > --- a/arch_init.c > +++ b/arch_init.c > @@ -284,7 +284,9 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data, > > if (!cache_is_cached(XBZRLE.cache, current_addr)) { > if (!last_stage) { > - cache_insert(XBZRLE.cache, current_addr, current_data); > + if (cache_insert(XBZRLE.cache, current_addr, current_data) == -1) { > + return -1; > + } > } > acct_info.xbzrle_cache_miss++; > return -1; > diff --git a/include/migration/page_cache.h b/include/migration/page_cache.h > index 87894fe..d156f0d 100644 > --- a/include/migration/page_cache.h > +++ b/include/migration/page_cache.h > @@ -60,11 +60,13 @@ uint8_t *get_cached_data(const PageCache *cache, uint64_t addr); > * cache_insert: insert the page into the cache. the page cache > * will dup the data on insert. the previous value will be overwritten > * > + * Returns -1 on error > + * > * @cache pointer to the PageCache struct > * @addr: page address > * @pdata: pointer to the page > */ > -void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata); > +int cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata); > > /** > * cache_resize: resize the page cache. In case of size reduction the extra > diff --git a/page_cache.c b/page_cache.c > index 62a53f8..69e8329 100644 > --- a/page_cache.c > +++ b/page_cache.c > @@ -150,7 +150,7 @@ uint8_t *get_cached_data(const PageCache *cache, uint64_t addr) > return cache_get_by_addr(cache, addr)->it_data; > } > > -void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata) > +int cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata) > { > > CacheItem *it = NULL; > @@ -161,16 +161,22 @@ void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata) > /* actual update of entry */ > it = cache_get_by_addr(cache, addr); > > - /* free old cached data if any */ > - g_free(it->it_data); > - > + /* allocate page */ > if (!it->it_data) { > cache->num_items++; > + it->it_data = g_try_malloc(cache->page_size); > + if (!it->it_data) { > + DPRINTF("Error allocating page\n"); > + return -1; > + } It feels like it would have been correct to do the num_items++ after the allocation test (although since the num_items doesn't seem to be used anywhere that's not a show-stopper, but worth fixing sometime). > } > > - it->it_data = g_memdup(pdata, cache->page_size); > + memcpy(it->it_data, pdata, cache->page_size); > + > it->it_age = ++cache->max_item_age; > it->it_addr = addr; > + > + return 0; > } > > int64_t cache_resize(PageCache *cache, int64_t new_num_pages) > -- > 1.8.3.1 Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On 01/30/2014 06:08 PM, Dr. David Alan Gilbert wrote: > * Orit Wasserman (owasserm@redhat.com) wrote: >> It is better to fail migration in case of failure to >> allocate new cache item > > Does this actually fail migration or just drop back to sending an uncompressed > page? (I think the latter, and that's an even better result). > It fails the migration, if the users wants to disable compression it can do it and start migration again. >> Signed-off-by: Orit Wasserman <owasserm@redhat.com> >> --- >> arch_init.c | 4 +++- >> include/migration/page_cache.h | 4 +++- >> page_cache.c | 16 +++++++++++----- >> 3 files changed, 17 insertions(+), 7 deletions(-) >> >> diff --git a/arch_init.c b/arch_init.c >> index 806d096..0bfbc5a 100644 >> --- a/arch_init.c >> +++ b/arch_init.c >> @@ -284,7 +284,9 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data, >> >> if (!cache_is_cached(XBZRLE.cache, current_addr)) { >> if (!last_stage) { >> - cache_insert(XBZRLE.cache, current_addr, current_data); >> + if (cache_insert(XBZRLE.cache, current_addr, current_data) == -1) { >> + return -1; >> + } >> } >> acct_info.xbzrle_cache_miss++; >> return -1; >> diff --git a/include/migration/page_cache.h b/include/migration/page_cache.h >> index 87894fe..d156f0d 100644 >> --- a/include/migration/page_cache.h >> +++ b/include/migration/page_cache.h >> @@ -60,11 +60,13 @@ uint8_t *get_cached_data(const PageCache *cache, uint64_t addr); >> * cache_insert: insert the page into the cache. the page cache >> * will dup the data on insert. the previous value will be overwritten >> * >> + * Returns -1 on error >> + * >> * @cache pointer to the PageCache struct >> * @addr: page address >> * @pdata: pointer to the page >> */ >> -void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata); >> +int cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata); >> >> /** >> * cache_resize: resize the page cache. In case of size reduction the extra >> diff --git a/page_cache.c b/page_cache.c >> index 62a53f8..69e8329 100644 >> --- a/page_cache.c >> +++ b/page_cache.c >> @@ -150,7 +150,7 @@ uint8_t *get_cached_data(const PageCache *cache, uint64_t addr) >> return cache_get_by_addr(cache, addr)->it_data; >> } >> >> -void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata) >> +int cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata) >> { >> >> CacheItem *it = NULL; >> @@ -161,16 +161,22 @@ void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata) >> /* actual update of entry */ >> it = cache_get_by_addr(cache, addr); >> >> - /* free old cached data if any */ >> - g_free(it->it_data); >> - >> + /* allocate page */ >> if (!it->it_data) { >> cache->num_items++; >> + it->it_data = g_try_malloc(cache->page_size); >> + if (!it->it_data) { >> + DPRINTF("Error allocating page\n"); >> + return -1; >> + } > > It feels like it would have been correct to do the num_items++ after the > allocation test (although since the num_items doesn't seem to be used > anywhere that's not a show-stopper, but worth fixing sometime). > You are correct, I will move it after allocation. Orit >> } >> >> - it->it_data = g_memdup(pdata, cache->page_size); >> + memcpy(it->it_data, pdata, cache->page_size); >> + >> it->it_age = ++cache->max_item_age; >> it->it_addr = addr; >> + >> + return 0; >> } >> >> int64_t cache_resize(PageCache *cache, int64_t new_num_pages) >> -- >> 1.8.3.1 > > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > > Dave > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >
Orit Wasserman <owasserm@redhat.com> wrote: > It is better to fail migration in case of failure to > allocate new cache item > > Signed-off-by: Orit Wasserman <owasserm@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com>
diff --git a/arch_init.c b/arch_init.c index 806d096..0bfbc5a 100644 --- a/arch_init.c +++ b/arch_init.c @@ -284,7 +284,9 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data, if (!cache_is_cached(XBZRLE.cache, current_addr)) { if (!last_stage) { - cache_insert(XBZRLE.cache, current_addr, current_data); + if (cache_insert(XBZRLE.cache, current_addr, current_data) == -1) { + return -1; + } } acct_info.xbzrle_cache_miss++; return -1; diff --git a/include/migration/page_cache.h b/include/migration/page_cache.h index 87894fe..d156f0d 100644 --- a/include/migration/page_cache.h +++ b/include/migration/page_cache.h @@ -60,11 +60,13 @@ uint8_t *get_cached_data(const PageCache *cache, uint64_t addr); * cache_insert: insert the page into the cache. the page cache * will dup the data on insert. the previous value will be overwritten * + * Returns -1 on error + * * @cache pointer to the PageCache struct * @addr: page address * @pdata: pointer to the page */ -void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata); +int cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata); /** * cache_resize: resize the page cache. In case of size reduction the extra diff --git a/page_cache.c b/page_cache.c index 62a53f8..69e8329 100644 --- a/page_cache.c +++ b/page_cache.c @@ -150,7 +150,7 @@ uint8_t *get_cached_data(const PageCache *cache, uint64_t addr) return cache_get_by_addr(cache, addr)->it_data; } -void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata) +int cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata) { CacheItem *it = NULL; @@ -161,16 +161,22 @@ void cache_insert(PageCache *cache, uint64_t addr, uint8_t *pdata) /* actual update of entry */ it = cache_get_by_addr(cache, addr); - /* free old cached data if any */ - g_free(it->it_data); - + /* allocate page */ if (!it->it_data) { cache->num_items++; + it->it_data = g_try_malloc(cache->page_size); + if (!it->it_data) { + DPRINTF("Error allocating page\n"); + return -1; + } } - it->it_data = g_memdup(pdata, cache->page_size); + memcpy(it->it_data, pdata, cache->page_size); + it->it_age = ++cache->max_item_age; it->it_addr = addr; + + return 0; } int64_t cache_resize(PageCache *cache, int64_t new_num_pages)
It is better to fail migration in case of failure to allocate new cache item Signed-off-by: Orit Wasserman <owasserm@redhat.com> --- arch_init.c | 4 +++- include/migration/page_cache.h | 4 +++- page_cache.c | 16 +++++++++++----- 3 files changed, 17 insertions(+), 7 deletions(-)