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mirror of https://git.FreeBSD.org/src.git synced 2025-01-04 12:52:15 +00:00

Don't lower the ipl when returning from handling an interrupt.

If the ipl is lowered here, a machine can rapidly run out of stack
space when it is under heavy interrupt load.   Without this fix,
my test machine would fall over within a few seconds when forwarding
14,000 packets/sec.  With the patch, it has been up for over 24 hours
and has built the world at the same time.

submitted by: dfr@freebsd.org
This commit is contained in:
Andrew Gallatin 1999-10-30 15:20:31 +00:00
parent e1e5fdf6d4
commit c89564e46e
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=52672

View File

@ -263,9 +263,6 @@ Ler1: LDGP(pv)
CALL(do_sir) /* do the SIR; lowers IPL */
Lchkast:
ldiq a0, ALPHA_PSL_IPL_0 /* drop IPL to zero*/
call_pal PAL_OSF1_swpipl
and s1, ALPHA_PSL_USERMODE, t0 /* are we returning to user? */
beq t0, Lrestoreregs /* no: just return */