diff --git a/config/common_linuxapp b/config/common_linuxapp
index f1638db..a74cbab 100644
--- a/config/common_linuxapp
+++ b/config/common_linuxapp
@@ -110,6 +110,7 @@ CONFIG_RTE_EAL_PMD_PATH=""
 
 #
 # Special configurations in PCI Config Space for high performance
+# They are all deprecated, and will be removed later.
 #
 CONFIG_RTE_PCI_CONFIG=n
 CONFIG_RTE_PCI_EXTENDED_TAG=""
diff --git a/lib/librte_eal/common/eal_common_pci.c b/lib/librte_eal/common/eal_common_pci.c
index 96d5113..366fb46 100644
--- a/lib/librte_eal/common/eal_common_pci.c
+++ b/lib/librte_eal/common/eal_common_pci.c
@@ -180,13 +180,6 @@ rte_eal_pci_probe_one_driver(struct rte_pci_driver *dr, struct rte_pci_device *d
 		}
 
 		if (dr->drv_flags & RTE_PCI_DRV_NEED_MAPPING) {
-#ifdef RTE_PCI_CONFIG
-			/*
-			 * Set PCIe config space for high performance.
-			 * Return value can be ignored.
-			 */
-			pci_config_space_set(dev);
-#endif
 			/* map resources for devices that use igb_uio */
 			ret = rte_eal_pci_map_device(dev);
 			if (ret != 0)
diff --git a/lib/librte_eal/common/include/rte_pci.h b/lib/librte_eal/common/include/rte_pci.h
index 067e084..189d509 100644
--- a/lib/librte_eal/common/include/rte_pci.h
+++ b/lib/librte_eal/common/include/rte_pci.h
@@ -580,12 +580,14 @@ void rte_eal_pci_ioport_write(struct rte_pci_ioport *p,
 #ifdef RTE_PCI_CONFIG
 /**
  * Set special config space registers for performance purpose.
+ * It is deprecated, as all configurations have been moved into
+ * each PMDs respectively.
  *
  * @param dev
  *   A pointer to a rte_pci_device structure describing the device
  *   to use
  */
-void pci_config_space_set(struct rte_pci_device *dev);
+void pci_config_space_set(struct rte_pci_device *dev) __rte_deprecated;
 #endif /* RTE_PCI_CONFIG */
 
 #ifdef __cplusplus
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
index 4346973..4c45452 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
@@ -482,92 +482,14 @@ error:
 }
 
 #ifdef RTE_PCI_CONFIG
-static int
-pci_config_extended_tag(struct rte_pci_device *dev)
-{
-	struct rte_pci_addr *loc = &dev->addr;
-	char filename[PATH_MAX];
-	char buf[BUFSIZ];
-	FILE *f;
-
-	/* not configured, let it as is */
-	if (strncmp(RTE_PCI_EXTENDED_TAG, "on", 2) != 0 &&
-		strncmp(RTE_PCI_EXTENDED_TAG, "off", 3) != 0)
-		return 0;
-
-	snprintf(filename, sizeof(filename),
-		SYSFS_PCI_DEVICES "/" PCI_PRI_FMT "/" "extended_tag",
-		loc->domain, loc->bus, loc->devid, loc->function);
-	f = fopen(filename, "rw+");
-	if (!f)
-		return -1;
-
-	fgets(buf, sizeof(buf), f);
-	if (strncmp(RTE_PCI_EXTENDED_TAG, "on", 2) == 0) {
-		/* enable Extended Tag*/
-		if (strncmp(buf, "on", 2) != 0) {
-			fseek(f, 0, SEEK_SET);
-			fputs("on", f);
-		}
-	} else {
-		/* disable Extended Tag */
-		if (strncmp(buf, "off", 3) != 0) {
-			fseek(f, 0, SEEK_SET);
-			fputs("off", f);
-		}
-	}
-	fclose(f);
-
-	return 0;
-}
-
-static int
-pci_config_max_read_request_size(struct rte_pci_device *dev)
-{
-	struct rte_pci_addr *loc = &dev->addr;
-	char filename[PATH_MAX];
-	char buf[BUFSIZ], param[BUFSIZ];
-	FILE *f;
-	/* size can be 128, 256, 512, 1024, 2048, 4096 */
-	uint32_t max_size = RTE_PCI_MAX_READ_REQUEST_SIZE;
-
-	/* not configured, let it as is */
-	if (!max_size)
-		return 0;
-
-	snprintf(filename, sizeof(filename),
-		SYSFS_PCI_DEVICES "/" PCI_PRI_FMT "/" "max_read_request_size",
-			loc->domain, loc->bus, loc->devid, loc->function);
-	f = fopen(filename, "rw+");
-	if (!f)
-		return -1;
-
-	fgets(buf, sizeof(buf), f);
-	snprintf(param, sizeof(param), "%d", max_size);
-
-	/* check if the size to be set is the same as current */
-	if (strcmp(buf, param) == 0) {
-		fclose(f);
-		return 0;
-	}
-	fseek(f, 0, SEEK_SET);
-	fputs(param, f);
-	fclose(f);
-
-	return 0;
-}
-
+/*
+ * It is deprecated, all its configurations have been moved into
+ * each PMD respectively.
+ */
 void
-pci_config_space_set(struct rte_pci_device *dev)
+pci_config_space_set(__rte_unused struct rte_pci_device *dev)
 {
-	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
-		return;
-
-	/* configure extended tag */
-	pci_config_extended_tag(dev);
-
-	/* configure max read request size */
-	pci_config_max_read_request_size(dev);
+	RTE_LOG(DEBUG, EAL, "Nothing here, as it is deprecated\n");
 }
 #endif
 
