From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59869) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W8uAY-0001zi-Hd for qemu-devel@nongnu.org; Thu, 30 Jan 2014 11:08:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W8uAS-00073C-Da for qemu-devel@nongnu.org; Thu, 30 Jan 2014 11:08:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50736) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W8uAS-000736-5Z for qemu-devel@nongnu.org; Thu, 30 Jan 2014 11:08:40 -0500 Date: Thu, 30 Jan 2014 16:08:32 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20140130160831.GC2655@work-vm> References: <1391066055-17024-1-git-send-email-owasserm@redhat.com> <1391066055-17024-7-git-send-email-owasserm@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1391066055-17024-7-git-send-email-owasserm@redhat.com> Subject: Re: [Qemu-devel] [PATCH 6/6] Don't abort on memory allocation error List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Orit Wasserman Cc: peter.maydell@linaro.org, qemu-devel@nongnu.org, anthony@codemonkey.ws, quintela@redhat.com * 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 > --- > 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 Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK