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OS-7753 THREAD_KPRI_RELEASE does nothing of the sort
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

*** 19,28 **** --- 19,29 ---- * CDDL HEADER END */ /* * Copyright 2009 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. + * Copyright 2019 Joyent, Inc. */ /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */ /* All Rights Reserved */
*** 219,262 **** /* * Wait for all of the direct IO operations to finish */ - uint32_t ufs_directio_drop_kpri = 0; /* enable kpri hack */ - static int directio_wait(struct directio_buf *tail, long *bytes_iop) { int error = 0, newerror; struct directio_buf *dbp; - uint_t kpri_req_save; /* * The linked list of directio buf structures is maintained * in reverse order (tail->last request->penultimate request->...) */ - /* - * This is the k_pri_req hack. Large numbers of threads - * sleeping with kernel priority will cause scheduler thrashing - * on an MP machine. This can be seen running Oracle using - * directio to ufs files. Sleep at normal priority here to - * more closely mimic physio to a device partition. This - * workaround is disabled by default as a niced thread could - * be starved from running while holding i_rwlock and i_contents. - */ - if (ufs_directio_drop_kpri) { - kpri_req_save = curthread->t_kpri_req; - curthread->t_kpri_req = 0; - } while ((dbp = tail) != NULL) { tail = dbp->next; newerror = directio_wait_one(dbp, bytes_iop); if (error == 0) error = newerror; } - if (ufs_directio_drop_kpri) - curthread->t_kpri_req = kpri_req_save; return (error); } /* * Initiate direct IO request */ --- 220,245 ----