----- Forwarded message from Mikulas Patocka <mpatocka@xxxxxxxxxx> ----- Date: Wed, 25 Feb 2009 14:26:08 -0500 (EST) From: Mikulas Patocka <mpatocka@xxxxxxxxxx> Subject: Re: [PATCH 2/3] check for completed exception after dropped lock To: dm-devek@xxxxxxxxxx cc: Alasdair G Kergon <agk@xxxxxxxxxx> > - up_write(&s->lock); > - pe = alloc_pending_exception(s); > - down_write(&s->lock); BTW. shouldn't this rw-semaphore be replaced with a mutex or normal semaphore? It is never locked for read. (it used to be in locked for reads in RHEL-4). Mutex has better performance than a rw-semaphore --- it takes fewer cycles and it also guarantees first-in-first-out ordering. Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
