From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39677) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YJi0W-0006be-QK for qemu-devel@nongnu.org; Fri, 06 Feb 2015 07:27:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YJi0R-0002eE-OE for qemu-devel@nongnu.org; Fri, 06 Feb 2015 07:27:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48283) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YJi0R-0002e3-Hx for qemu-devel@nongnu.org; Fri, 06 Feb 2015 07:27:31 -0500 Date: Fri, 6 Feb 2015 12:27:25 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20150206122725.GJ2364@work-vm> References: <1422875149-13198-1-git-send-email-liang.z.li@intel.com> <1422875149-13198-11-git-send-email-liang.z.li@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1422875149-13198-11-git-send-email-liang.z.li@intel.com> Subject: Re: [Qemu-devel] [v4 10/13] migration: Add the core code for decompression List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Liang Li Cc: quintela@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org, lcapitulino@redhat.com, Yang Zhang , amit.shah@redhat.com * Liang Li (liang.z.li@intel.com) wrote: > Implement the core logic of multiple thread decompression, > the decompression can work now. > > Signed-off-by: Liang Li > Signed-off-by: Yang Zhang > --- > arch_init.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 47 insertions(+), 2 deletions(-) > > diff --git a/arch_init.c b/arch_init.c > index 8ef0315..549fdbb 100644 > --- a/arch_init.c > +++ b/arch_init.c > @@ -814,6 +814,13 @@ static inline void start_compression(CompressParam *param) > qemu_mutex_unlock(¶m->mutex); > } > > +static inline void start_decompression(DecompressParam *param) > +{ > + qemu_mutex_lock(¶m->mutex); > + param->busy = true; > + qemu_cond_signal(¶m->cond); > + qemu_mutex_unlock(¶m->mutex); > +} > > static uint64_t bytes_transferred; > > @@ -1347,8 +1354,27 @@ void ram_handle_compressed(void *host, uint8_t ch, uint64_t size) > > static void *do_data_decompress(void *opaque) > { > + DecompressParam *param = opaque; > + size_t pagesize; > + > while (!quit_thread) { > - /* To be done */ > + qemu_mutex_lock(¶m->mutex); > + while (!param->busy) { > + qemu_cond_wait(¶m->cond, ¶m->mutex); > + if (quit_thread) { > + break; > + } > + pagesize = TARGET_PAGE_SIZE; > + /* uncompress() will return failed in some case, especially > + * when the page is dirted when doing the compression, it's > + * not a problem because the dirty page will be retransferred > + * and uncompress() won't break the data in other pages. > + */ > + uncompress((Bytef *)param->des, &pagesize, > + (const Bytef *)param->compbuf, param->len); > + param->busy = false; > + } > + qemu_mutex_unlock(¶m->mutex); > } Again, similar question to the compress thread; what ensures that teh cond_signal for quit_thread happens while this loop is at the cond_wait? Again mainly in error cases. Dave > > return NULL; > @@ -1379,6 +1405,9 @@ void migrate_decompress_threads_join(void) > quit_thread = true; > thread_count = migrate_decompress_threads(); > for (i = 0; i < thread_count; i++) { > + qemu_cond_signal(&decomp_param[i].cond); > + } > + for (i = 0; i < thread_count; i++) { > qemu_thread_join(decompress_threads + i); > qemu_mutex_destroy(&decomp_param[i].mutex); > qemu_cond_destroy(&decomp_param[i].cond); > @@ -1395,7 +1424,23 @@ void migrate_decompress_threads_join(void) > static void decompress_data_with_multi_threads(uint8_t *compbuf, > void *host, int len) > { > - /* To be done */ > + int idx, thread_count; > + > + thread_count = migrate_decompress_threads(); > + while (true) { > + for (idx = 0; idx < thread_count; idx++) { > + if (!decomp_param[idx].busy) { > + memcpy(decomp_param[idx].compbuf, compbuf, len); > + decomp_param[idx].des = host; > + decomp_param[idx].len = len; > + start_decompression(&decomp_param[idx]); > + break; > + } > + } > + if (idx < thread_count) { > + break; > + } > + } > } > > static int ram_load(QEMUFile *f, void *opaque, int version_id) > -- > 1.9.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK