diff options
author | wes <wes@FreeBSD.org> | 2003-03-31 21:09:57 +0000 |
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committer | wes <wes@FreeBSD.org> | 2003-03-31 21:09:57 +0000 |
commit | ca1839cb9191762cd4c49990a18f78fd9798c4d1 (patch) | |
tree | f83c7306439c7baa61bbd7bf0a72fa416688f426 /sys | |
parent | 35e71f4a050af9100a931d737080b2818efa8c63 (diff) | |
download | FreeBSD-src-ca1839cb9191762cd4c49990a18f78fd9798c4d1.zip FreeBSD-src-ca1839cb9191762cd4c49990a18f78fd9798c4d1.tar.gz |
Add a facility allowing processes to inform the VM subsystem they are
critical and should not be killed when pageout is looking for more
memory pages in all the wrong places.
Reviewed by: arch@
Sponsored by: St. Bernard Software
Diffstat (limited to 'sys')
-rw-r--r-- | sys/sys/mman.h | 1 | ||||
-rw-r--r-- | sys/sys/proc.h | 1 | ||||
-rw-r--r-- | sys/vm/vm_mmap.c | 15 | ||||
-rw-r--r-- | sys/vm/vm_pageout.c | 3 |
4 files changed, 19 insertions, 1 deletions
diff --git a/sys/sys/mman.h b/sys/sys/mman.h index 71ac90c..f8b94cc 100644 --- a/sys/sys/mman.h +++ b/sys/sys/mman.h @@ -124,6 +124,7 @@ #define MADV_AUTOSYNC 7 /* revert to default flushing strategy */ #define MADV_NOCORE 8 /* do not include these pages in a core file */ #define MADV_CORE 9 /* revert to including pages in a core file */ +#define MADV_PROTECT 10 /* protect process from pageout kill */ /* * Return bits from mincore diff --git a/sys/sys/proc.h b/sys/sys/proc.h index 77464a0..8e25aa0 100644 --- a/sys/sys/proc.h +++ b/sys/sys/proc.h @@ -629,6 +629,7 @@ struct proc { #define P_EXEC 0x04000 /* Process called exec. */ #define P_THREADED 0x08000 /* Process is using threads. */ #define P_CONTINUED 0x10000 /* Proc has continued from a stopped state. */ +#define P_PROTECTED 0x20000 /* Do not kill on memory overcommit. */ /* flags that control how threads may be suspended for some reason */ #define P_STOPPED_SIG 0x20000 /* Stopped due to SIGSTOP/SIGTSTP */ diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c index 93c8524..d20756f 100644 --- a/sys/vm/vm_mmap.c +++ b/sys/vm/vm_mmap.c @@ -752,8 +752,23 @@ madvise(td, uap) { vm_offset_t start, end; vm_map_t map; + struct proc *p; + int error; /* + * Check for our special case, advising the swap pager we are + * "immortal." + */ + if (uap->behav == MADV_PROTECT) { + p = td->td_proc; + PROC_LOCK(p); + error = suser(td); + if (error == 0) + p->p_flag |= P_PROTECTED; + PROC_UNLOCK(p); + return (error); + } + /* * Check for illegal behavior */ if (uap->behav < 0 || uap->behav > MADV_CORE) diff --git a/sys/vm/vm_pageout.c b/sys/vm/vm_pageout.c index dab4ae2..8c07be2 100644 --- a/sys/vm/vm_pageout.c +++ b/sys/vm/vm_pageout.c @@ -1184,9 +1184,10 @@ rescan0: if (PROC_TRYLOCK(p) == 0) continue; /* - * if this is a system process, skip it + * If this is a system or protected process, skip it. */ if ((p->p_flag & P_SYSTEM) || (p->p_pid == 1) || + (p->p_flag & P_PROTECTED) || ((p->p_pid < 48) && (vm_swap_size != 0))) { PROC_UNLOCK(p); continue; |