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author | Olaf Hering <olaf@aepfle.de> | 2012-02-20 21:18:44 +0100 |
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committer | Olaf Hering <olaf@aepfle.de> | 2012-02-20 21:18:44 +0100 |
commit | d3fd52a24bc96b0f9cd16a5bd0caa768c2043827 (patch) | |
tree | 9d2bf19df0c473c8a290ee31248bae62afb89654 /tools/xenpaging/xenpaging.c | |
parent | 7520fdef279e12a9da5de7eab088dc7abc9fa230 (diff) | |
download | xen-d3fd52a24bc96b0f9cd16a5bd0caa768c2043827.tar.gz xen-d3fd52a24bc96b0f9cd16a5bd0caa768c2043827.tar.bz2 xen-d3fd52a24bc96b0f9cd16a5bd0caa768c2043827.zip |
xenpaging: move nominate+evict into single function
Move all code to evict a single gfn into one function. This simplifies
error handling in caller. The function returns -1 on fatal error, 0 on
success and 1 if the gfn cant be paged.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Committed-by: Ian Jackson <ian.jackson.citrix.com>
Diffstat (limited to 'tools/xenpaging/xenpaging.c')
-rw-r--r-- | tools/xenpaging/xenpaging.c | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/tools/xenpaging/xenpaging.c b/tools/xenpaging/xenpaging.c index 6cead5e3c7..5dff4ff5f2 100644 --- a/tools/xenpaging/xenpaging.c +++ b/tools/xenpaging/xenpaging.c @@ -571,6 +571,11 @@ static void put_response(struct mem_event *mem_event, mem_event_response_t *rsp) RING_PUSH_RESPONSES(back_ring); } +/* Evict a given gfn + * Returns < 0 on fatal error + * Returns 0 on successful evict + * Returns > 0 if gfn can not be evicted + */ static int xenpaging_evict_page(struct xenpaging *paging, unsigned long gfn, int fd, int slot) { xc_interface *xch = paging->xc_handle; @@ -580,31 +585,51 @@ static int xenpaging_evict_page(struct xenpaging *paging, unsigned long gfn, int DECLARE_DOMCTL; + /* Nominate page */ + ret = xc_mem_paging_nominate(xch, paging->mem_event.domain_id, gfn); + if ( ret < 0 ) + { + /* unpageable gfn is indicated by EBUSY */ + if ( errno == EBUSY ) + ret = 1; + else + PERROR("Error nominating page %lx", gfn); + goto out; + } + /* Map page */ - ret = -EFAULT; page = xc_map_foreign_pages(xch, paging->mem_event.domain_id, PROT_READ, &victim, 1); if ( page == NULL ) { PERROR("Error mapping page %lx", gfn); + ret = -1; goto out; } /* Copy page */ ret = write_page(fd, page, slot); - if ( ret != 0 ) + if ( ret < 0 ) { PERROR("Error copying page %lx", gfn); munmap(page, PAGE_SIZE); + ret = -1; goto out; } + /* Release page */ munmap(page, PAGE_SIZE); /* Tell Xen to evict page */ ret = xc_mem_paging_evict(xch, paging->mem_event.domain_id, gfn); - if ( ret != 0 ) + if ( ret < 0 ) { - PERROR("Error evicting page %lx", gfn); + /* A gfn in use is indicated by EBUSY */ + if ( errno == EBUSY ) + { + ret = 1; + DPRINTF("Nominated page %lx busy", gfn); + } else + PERROR("Error evicting page %lx", gfn); goto out; } @@ -619,6 +644,8 @@ static int xenpaging_evict_page(struct xenpaging *paging, unsigned long gfn, int /* Record number of evicted pages */ paging->num_paged_out++; + ret = 0; + out: return ret; } @@ -753,9 +780,10 @@ static int evict_victim(struct xenpaging *paging, int fd, int slot) ret = -EINTR; goto out; } - ret = xc_mem_paging_nominate(xch, paging->mem_event.domain_id, gfn); - if ( ret == 0 ) - ret = xenpaging_evict_page(paging, gfn, fd, slot); + + ret = xenpaging_evict_page(paging, gfn, fd, slot); + if ( ret < 0 ) + goto out; } while ( ret ); |