Author: mav
Date: Sat Feb 18 06:03:16 2017
New Revision: 313910
URL: https://svnweb.freebsd.org/changeset/base/313910

Log:
  Change XCOPY memory allocations.
  
  Before this change XCOPY code could allocate memory in chunks up to 16-32MB
  (VMware does XCOPY in 4MB chunks by default), that could be difficult for
  VM subsystem to do due to KVA fragmentation, that sometimes created huge
  allocation delays, blocking any I/O for respective LU for that time.
  
  This change limits allocations down to TPC_MAX_IO_SIZE, which is 1MB now.
  1MB is also not a cookie, but ZFS also can do that for large blocks, so
  it should be less dramatic.  As drawback this increases CPU overhead, but
  it still look acceptable comparing to time consumed by ZFS read/write.
  
  MFC after:    1 week

Modified:
  head/sys/cam/ctl/ctl_tpc.c

Modified: head/sys/cam/ctl/ctl_tpc.c
==============================================================================
--- head/sys/cam/ctl/ctl_tpc.c  Sat Feb 18 05:07:53 2017        (r313909)
+++ head/sys/cam/ctl/ctl_tpc.c  Sat Feb 18 06:03:16 2017        (r313910)
@@ -85,6 +85,7 @@ struct tpc_io {
        uint8_t                  target;
        uint32_t                 cscd;
        uint64_t                 lun;
+       uint8_t                 *buf;
        struct tpc_list         *list;
        struct runl              run;
        TAILQ_ENTRY(tpc_io)      rlinks;
@@ -127,7 +128,6 @@ struct tpc_list {
        off_t                    curbytes;
        int                      curops;
        int                      stage;
-       uint8_t                 *buf;
        off_t                    segsectors;
        off_t                    segbytes;
        int                      tbdio;
@@ -813,9 +813,9 @@ tpc_process_b2b(struct tpc_list *list)
                while ((tior = TAILQ_FIRST(&list->allio)) != NULL) {
                        TAILQ_REMOVE(&list->allio, tior, links);
                        ctl_free_io(tior->io);
+                       free(tior->buf, M_CTL);
                        free(tior, M_CTL);
                }
-               free(list->buf, M_CTL);
                if (list->abort) {
                        ctl_set_task_aborted(list->ctsio);
                        return (CTL_RETVAL_ERROR);
@@ -874,7 +874,6 @@ tpc_process_b2b(struct tpc_list *list)
                return (CTL_RETVAL_ERROR);
        }
 
-       list->buf = malloc(numbytes, M_CTL, M_WAITOK);
        list->segbytes = numbytes;
        list->segsectors = numbytes / dstblock;
        donebytes = 0;
@@ -894,11 +893,12 @@ tpc_process_b2b(struct tpc_list *list)
 
                tior = malloc(sizeof(*tior), M_CTL, M_WAITOK | M_ZERO);
                TAILQ_INIT(&tior->run);
+               tior->buf = malloc(roundbytes, M_CTL, M_WAITOK);
                tior->list = list;
                TAILQ_INSERT_TAIL(&list->allio, tior, links);
                tior->io = tpcl_alloc_io();
                ctl_scsi_read_write(tior->io,
-                                   /*data_ptr*/ &list->buf[donebytes],
+                                   /*data_ptr*/ tior->buf,
                                    /*data_len*/ roundbytes,
                                    /*read_op*/ 1,
                                    /*byte2*/ 0,
@@ -919,7 +919,7 @@ tpc_process_b2b(struct tpc_list *list)
                TAILQ_INSERT_TAIL(&list->allio, tiow, links);
                tiow->io = tpcl_alloc_io();
                ctl_scsi_read_write(tiow->io,
-                                   /*data_ptr*/ &list->buf[donebytes],
+                                   /*data_ptr*/ tior->buf,
                                    /*data_len*/ roundbytes,
                                    /*read_op*/ 0,
                                    /*byte2*/ 0,
@@ -1029,9 +1029,9 @@ tpc_process_register_key(struct tpc_list
                while ((tio = TAILQ_FIRST(&list->allio)) != NULL) {
                        TAILQ_REMOVE(&list->allio, tio, links);
                        ctl_free_io(tio->io);
+                       free(tio->buf, M_CTL);
                        free(tio, M_CTL);
                }
-               free(list->buf, M_CTL);
                if (list->abort) {
                        ctl_set_task_aborted(list->ctsio);
                        return (CTL_RETVAL_ERROR);
@@ -1064,9 +1064,9 @@ tpc_process_register_key(struct tpc_list
        TAILQ_INSERT_TAIL(&list->allio, tio, links);
        tio->io = tpcl_alloc_io();
        datalen = sizeof(struct scsi_per_res_out_parms);
-       list->buf = malloc(datalen, M_CTL, M_WAITOK);
+       tio->buf = malloc(datalen, M_CTL, M_WAITOK);
        ctl_scsi_persistent_res_out(tio->io,
-           list->buf, datalen, SPRO_REGISTER, -1,
+           tio->buf, datalen, SPRO_REGISTER, -1,
            scsi_8btou64(seg->res_key), scsi_8btou64(seg->sa_res_key),
            /*tag_type*/ CTL_TAG_SIMPLE, /*control*/ 0);
        tio->io->io_hdr.retries = 3;
@@ -1166,9 +1166,9 @@ tpc_process_wut(struct tpc_list *list)
                while ((tio = TAILQ_FIRST(&list->allio)) != NULL) {
                        TAILQ_REMOVE(&list->allio, tio, links);
                        ctl_free_io(tio->io);
+                       free(tio->buf, M_CTL);
                        free(tio, M_CTL);
                }
-               free(list->buf, M_CTL);
                if (list->abort) {
                        ctl_set_task_aborted(list->ctsio);
                        return (CTL_RETVAL_ERROR);
@@ -1233,8 +1233,6 @@ tpc_process_wut(struct tpc_list *list)
                return (CTL_RETVAL_ERROR);
        }
 
-       list->buf = malloc(numbytes, M_CTL, M_WAITOK |
-           (list->token == NULL ? M_ZERO : 0));
        list->segbytes = numbytes;
        list->segsectors = numbytes / dstblock;
 //printf("Copy chunk of %ju sectors from %ju to %ju\n", list->segsectors,
@@ -1257,11 +1255,12 @@ tpc_process_wut(struct tpc_list *list)
 
                tior = malloc(sizeof(*tior), M_CTL, M_WAITOK | M_ZERO);
                TAILQ_INIT(&tior->run);
+               tior->buf = malloc(roundbytes, M_CTL, M_WAITOK);
                tior->list = list;
                TAILQ_INSERT_TAIL(&list->allio, tior, links);
                tior->io = tpcl_alloc_io();
                ctl_scsi_read_write(tior->io,
-                                   /*data_ptr*/ &list->buf[donebytes],
+                                   /*data_ptr*/ tior->buf,
                                    /*data_len*/ roundbytes,
                                    /*read_op*/ 1,
                                    /*byte2*/ 0,
@@ -1280,7 +1279,7 @@ tpc_process_wut(struct tpc_list *list)
                TAILQ_INSERT_TAIL(&list->allio, tiow, links);
                tiow->io = tpcl_alloc_io();
                ctl_scsi_read_write(tiow->io,
-                                   /*data_ptr*/ &list->buf[donebytes],
+                                   /*data_ptr*/ tior->buf,
                                    /*data_len*/ roundbytes,
                                    /*read_op*/ 0,
                                    /*byte2*/ 0,
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